J

COASTAL LAGOONS IN THE J

(VOLUME 111)

1. LADY'S ISLAND LAKE

J

Brenda Healy J Geoff Oliver Pat Hatch Jervis Good

February 1997 J

Prepared for the National Parks and Wildlife Service

(BioMar/Life) J J

I LJ 1. LADY'S ISLAND LAKE

CONTENTS

1.1 Study Area

1.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

1.2.1 Methods 1.2.2Results J 1.2.3Discussion 1.2.4Threats 1.2.5Evaluation J 1.2.6References

J 1.3 Vegetation Survey (Pat Hatch)

J 1.3.1 Site Description 1.3.2Methods 1.3.3Results Transect tables 1.3.4Evaluation

!.4 Ecotonal Coleoptera (Jervis Good)

1.4.1 Site description 1.4.2Methods 1.4.3Results J 1.4.4Evaluation 1.4.5 References

1.5 Summary and Evaluation Lady's Island Lake

1. LADY'S ISLAND LAKE, Co.

OS Grid Reference: T 099065,1.50 000 Sheet No: 77 J Alternative names: Our Lady's Island Lake, Loch Tochair

1.1 STUDY AREA

Generalfeatures Lady's Island Lake is a natural, brackish, percolating lagoon, situatedon the southeast coast of Co Wexford about 3 km west of CarnsorePoint and 5 km from Rosslare Harbour (Fig. 1.1.1). It is impounded by a sand andgravel barrier which has no natural outlet but is periodically breached to relieve flooding. The lakeis named after Lady's Island which has been connected to the mainland by acauseway since early Christian times, and is still a place of pilgrimage in August. Breaching of the barrier, which has been carried out sinceat least the 17thcentury, is needed to relieve flooding of farmland and also the pilgrimageroute around Lady's Island. The cut is made in Spring when water levelsare highest and the water level then falls until the lake becomes tidal for variable lengths oftime. The practice has become contentious, however, because water levels sometimes fall too low, allowingpredators to cross over the exposed bed of the lake to theimportant tern nesting sites on the Sgarbheen and Inish Islands. The lagoon is of great ornithological interest, not only forup to 5,000 wintering waterfowl but also due to the presence of breeding terncolonies (Hutchinson 1979, Delany 1995, Sheppard 1993). Sandwich terns (Sterna sandvicensis) are themost numerous, but Common (S. hirundo), Arctic (S. paradisaea) and, recentlyRoseate terns (S. dougalli) also breed. Following Rockabill Island, which holds thelargest colony in of the globally threatened Roseate terns, this lagoon holds the second largest colony in Ireland. There is almost no exploitation of the lake. Eels havebeen fished commercially in the past and there used to be some fishing for local consumptionwhen fish were plentiful, but this appears to have ceased. The main leisure activity is sail-boarding;a few small boats are seen in summer. Lady's Island Lake is the best documented lagoon in Ireland.There are published accounts of its geomorphology, ornithology, aquatic fauna and rare plantsand further papers on fauna and hydrology are in preparation. Faunal studiesare described in two publications (Healy et al. 1982, Norton and Healy 1984) andthree student theses. The cockle (Cerastoderma glaucum) population was listed in a survey ofthe species in Britain and Ireland (Boyden and Russell 1972). The long list ofpublications, not all of which are cited in this report, reflect the scientific value of thelake as possibly the best remaining example in Europe of a distinct and relatively rare geomorphologicalformation. Both the barrier and the lagoon itself have provided exceptional opportunities forstudying geomorphological, ecological and biological processes.

Due to ornithological value, the two islands are listed asa Refuge for Fauna and the lagoon is designated as a Special Protection Area. The barrierand lagoon shoreline are

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0 Fig. 1. 1. ISection of l .50 000 map showing locality of Lady'sIsland Lake D J

Lady's Island Lake J

also important for endangered plant species. The lagoon and barrierare a proposed J National Heritage Area (Site Code No. 00704). n i Climate and oceanographic influences Li (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979)The region experiences a mild oceanic climate with a smallannual temperature 7 range of only 8°C and frequent cyclonic depressions accompanied byrain and strong winds. The mean daily air temperature is 6.5°C in Januaryand 15°C in July. The growing rl i season (the period of mean daily air temperatures above 6 °C) is around 10 monthsand LJ as snow and frosts are rare, some plant growth ispossible in winter months. Annual rainfall is approximately 900 mm, and the number of raindays (1 mm or more) is <150. Winds are mainly from the southwest. Mean annual hourly windspeeds are between 5.9 m/s and a maximum wind speed of 47 m/s isestimated to occur once in 50 years. The mean annual number of hours of bright sunshine is 1700which is the highest for the country. Mean relative humidity is around 85% as on allIrish coasts.

Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce large waves, but inshore breakers rarely exceed 4.5 m with extremesreaching 8.5 m (Carter 1992). Maximum wave heights (averaging once in 50 years) are18-20 m (Couper 1983). Tides are semi-diurnal and the tidal range (MHWS-MLWS) at Rosslareis 3.1 m (Admiralty Tide Tables). Sea temperatures are lowest in February andhighest in August.

J Landscape and Geology The area surrounding the lake is flat, consisting almost entirelyof grazing or arable land with natural vegetation mostly confined to wet or rocky groundnear the coast. A complex series of glacial deposits overlies a relatively flat LowerPalaeozoic bedrock (Carter and Orford 1982). A granite intrusion forms the headlandat Carnsore Point and large granite boulders are numerous at the surface to thewest of the Point and in the southeast corner of Lady's Island Lake. Surface geology consists ofsand, gravel and gravelly till producing mostly dry mineral soils. 7 Li Lake topography The lake is 3.7 km long and 0.8-1.8 km wide.The area varies seasonally but is generally estimated at around 450 ha although there are estimates ofup to 900 ha in the literature. Sediments grade from soft sandy mud in the north tocoarse, sandy gravel near the barrier. The bed is stony in places e.g. at thesouth end of the peninsula at Lady's Island and on the south shore and there are numerous graniteboulders in the southeast.

rl Geomorphology of the harrier J Barrier systems extend uninterrupted for 12 km from Carnsore Pointto near Kilmore Quay. Early explanations for lagoon formation in the area suggestedthat they became isolated by westward migrating spits (Lowry and Carter 1981), butlater studies showed that the barrier on this part of the coast hasbeen, and still is, moving onshore by a "rolling-over" process rather than extending alongshore (Orford and Carter 1982).Coring of the lake revealed clay sediments with lacustrine floral remnants,dating from about 5000 y BP, underlying more recent sediments derived from thebarrier by washover

2 Level of bar in Feb. 1977, April 1979 and March Level(2 months of bar after cut) 27-vii. 'fg-" 1989 ------Highest recorded level ------OD S ---. owest level N Fig. 1.1.2 thebreach lake is relative made, showingto sea level. variations in the heightLady's of Island the Lake, Section through the region of the barrier bar and water levels in where the C C3 C2 O C C=7 Ci C C C C23 C C C23 C C O C C23 C C J

Lady's Island Lake

(Orford and Carter 1982). The original lagoon bed extends underthe barrier onto the shore where peat is visible at the surface in places.

The gravel-dominated barrier of Lady's Island Lake, known locally asthe Coombe, is overlain with small aeolian dunes. It is composed of stratifiedcoarse to fine gravels with median grain sizes between 0 and 4 (0.06-1.0 mm), toppedwith small aeolian sand dunes, interrupted by relict washover fans (Carter & Orford 1980,Ruz 1989). At the point where the breach is made, laminations of coarse sedimentsrepresenting washover

fans are visible at the cut face. However, the barrier crest has now stabilised at 5-12 m OD and washover only occurs in the region of thebreach (Fig. 1.1.2). The coarse sediments of the barrier allow extensive seaward seepage which issufficient to prevent the formation of outlet streams. Their absence is characteristic ofpercolation lagoons (Orford and Carter 1984).

The beach is severely eroded, due to long-term failure inthe supply of sediment, possibly aggravated by illegal gravel extraction near Carnsore Point.

Hydrology. Lake water levels were measured monthly from 1976-1980 (Healy etal. 1982), irregularly from 1981-1984 (Healy, unpublished), and weekly from 1985 (Hurley unpublished).

Fluctuations in water level follow a regular seasonal pattern, risingin winter to reach a maximum in spring when the barrier is usually breached. Inyears when breaching is not carried out, the level starts to fall in early summerwhen evaporation and seepage through the barrier exceed inputs from groundwater, streams, drainage and runofffrom surrounding land, and direct rainfall. Low summer levels expose rocksand areas of rock around the lake causing some mortality of fauna. The risein water level starts in September-October and by the end of January water has usuallycovered most of Sgarbheen and part of the pilgrimage path which borders theLady's Island peninsula. Inish is never completely covered but its stony beach, whereCommon and Arctic terns nest, becomes submerged. From about December, The pool at Bunargatein the southwest, which is isolated in summer, becomes joined to thelagoon allowing mixing of the waters and their fauna. From September to March thelagoon level normally rises a little over 2 in and, if the breach is notmade, stabilises at between 5 and 6 m OD untilthe summer drop in level. A water level range of 3.02m was recorded between 1976 and 1981.

J Breaching of the barrier is carried out when the springwater level is high, usually in April, but it may be delayed until May, or considered unnecessary.In 1996 the cut was completed on 26 February and sealed naturally after 10 days.Following completion of the cut, the water flows out for several days until thelagoon level falls below high tide mark. The lagoon then becomes tidal until the opening seals asa result of onshore and longshore transport of beach sediment. During tidal periods, the waterfalls well below levels which would be reached as a result of lossby seepage and evaporation and large expanses of the substratum are exposed. The bar which formsacross the sealed opening continues to build up gradually but finally stabilises. During theperiod 1975-1978, and in March 1989, the final level of the bar was 6.8m OD which is nearly 3 m above extreme high water of spring tides although waves may wash overduring storms. Landward 0

Lady's Island Lake EJ seepage of saltwater is usually observed in late summer andearly autumn, i.e. when the water level is low. The level in the lagoon usuallyremains above mean tide level, even in 0 summer, so the amount of landward percolation is probably alwayssmall. It is not clear whether landward seepage would continue to take place if thewater level in the lagoon were allowed to stabilise naturally. EJ

Salinity and water quality Seawater at approximately 34%o enters the lagoon by seepage throughthe barrier, by salt 0 spray being washed into the lagoon from the barrier, byoccasional overwash of the entrance bar and, most importantly, by tidal flow following breaching.Salinities between 2 and 40%o have been recorded in the lagoon asa whole. At most times when the lagoon tJ was isolated, the salinity was 0.5-2.0%o higher at the southend than at Lady's Island, showing direct influence of the sea, and lower in theextreme north where a small stream EJ enters. The pool at Bunargate in the southwest also receivessome freshwater and during its periods of isolation, which can last up to ninemonths, the salinity falls below that of the lagoon. Concentrations of 2-19%o were recorded here between 1977and 1991 but an tJ exceptional level of 26%o was reached in September 1990. Allother point sources of freshwater are too small to have any significant effect andthe main body of the lagoon has a more or less uniform salinity. Vertical stratification has beenobserved during calm 0 weather in summer but has not been investigated.

Seasonal fluctuations in salinity correspond to changes in water level.In years when the IJ breach sealed early before any significant tidal exchange could takeplace (e.g. in 1977, 1978 and 1979), the annual range was from 6-8%o inwinter to 12-16%o in summer. In years when there is a major influx of tidal seawater(e.g. 1980, 1981, 1983), the salinity IJ throughout most of the lagoon rises rapidly, and in 6of the 17 years for which measurements are available, salinities in summer reached over 30%o. Variationsfrom year to year are chiefly caused by differences in the proportionof lagoon water which is IJ replaced by seawater during periods of tidal flow. This dependson the length of time the inlet remains open, which in turn depends on tides andweather, and the degree of mixing brought about by winds, conditions which are unpredictable. In calmweather, tidal water 0 flows north through the centre of the lagoon and ebbsalong the same route so that regions on either side are little affected (observed in 1979).However, even when the IJ opening closes quickly, the salinity throughout the lagoon can riserapidly, especially if there are strong cross winds during tidal flow (e.g. in1980). 0 Changes in the salinity regime have occurred with high salinity,poly-euhaline phases in 1975-77, 1980-84 and 1988-90 alternating with low salinity oligo-mesohaline phasesin 1977-79 and 1985-87. The reasons for this pattern of cyclicalchange are not known. 0 During high salinity phases there were wide seasonal fluctuations insalinity while in low salinity phases differences between summer and winter were relatively small. IJ Eutrophication has increased since the early 1980s, due chiefly tonutrients from agricultural sources, and phytoplankton blooms have become more frequent. Someof the press reports about deteriorating conditions, however, have been misinterpretations of IJ faunal mortality resulting from extensive tidal flow. 0

4 Lady's Island Lake

1.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin.

1.2.1Methods

Environmental variables A profile of the barrier was obtained from previous studies(Fig 1.1.2).

The position of each sample area was determined using aGPS Personal Navigator ( Global Positioning Satellite, Garmin GPS 45). Manufacturers of theGPS state that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 0. S. mapand grid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o. precision). A photographic record was made of the site andlocal information sought concerning the background and recent history. J Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations A, B, D andE in order to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by J 5 LJ

Lady's Island Lake 0 inter- and intra-specific relationships of the fauna and non-random distributionwithin the water column. Abundance categories of present, common and abundantare purely 0 subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists (Hemipteraand Coleoptera in particular). Standard keys were used to identify remainingspecimens, EJ but many of these were larval or juvenile stages anddifficult to identify with certainty. Some groups require adult males for identification and these wereoften not available due to low population density and the limited number ofindividuals collected in the EJ time available (e.g. hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify when preserved (turbellarians, leeches). 0 All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same species. 0

1.2.2Results 0 Environmental Variables The lake was sampled on l.vii.96 during the first partof the survey and from 1-3.x.96 EJ during the more intensive survey.

EJ Five sampling stations were selected in the lake to reflectthe influences of substrate, freshwater and tidal inflows. Fig. 1.2.1 shows the position ofthese sampling stations in the lake. 0

Station A (OS 1046 0810) was located in the mostnortherly bay of the lake (Plate EJ 2.2.2). Substrate consisted of gravel, sand and silt, water depthvaried from 0 - 60 cms., and salinity measured 4 - 15 %o. D Station B (OS 1069 0749) was located at the northernend of the lake, to the east of Lay's Island (Plate 1.2.3). Substrate consisted of gravel and stonesalong the shoreline, with finer sand and soft anoxic mud in deeper water.Water depth varied from 0 - 75 EJ cms., and salinity measured up to 23 %o. Station C (OS 0894 0574) was located at the southwesternend of the lake in Bunargate Pool. Substrate consisted of fine sand, silt and anoxicmud, water depth El varied from 10- 50 cms., And salinity measured 6 - 10 %o Station D (OS 0834 0529) was located in the southwesterlycorner of the lake close 0 to the barrier (Plate 1.2..4). Substrate consisted mostly of sandwith gravel and silts and occasional stones. Water depth varied from 0-1 m., and salinity measured 26 %o. 0

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a 6

a J

Wexford 14 km.

7 Fig1.2.1Location Map of Sampling Stations in Lady's Island Lake J LJ

Table 1.2.1. Fauna Recorded at Lady'sIsland Lake, Co. Wexford. July and October1996. 0 ( ) = records for July 0 Stations (L.T. = light trap) Fauna A L.T.A B 1 L.T.B C L.T.C D LTD E L.LE Porifera ==1 E 0 Cnidaria_ Turbellaria Nemerteans 0

+ Annelids Arenicola marina + Hediste diversicolor + + + 0

1

1

Crustacea I Ostracoda a Cirripedia Balanus improvisus + + o 0 o 31 Mysidacea Neomysis integer (a) o c100 o c.100 + 1 Praunusflexuosus 1 0 1 + 9 Isopoda Idotea chelipes c o 4 o c300 + 75 + 1 Lekanesphaera hookeri a >100 + 38 a Amphipoda Gammarus zaddachi + + + 0 Orchestia gammarella +

F4,3 Decapoda Carcinus maenas F1,7 F2,7 F3,4 a Crangon crangon 3 1 a>100 a 82 a 130 o 5 o 5 Palaemonetes varians a Arachnids 1 Thysanura tJ Ephemeroptera + OdonataIschnura elegans + Plecoptera 0 Trichoptera Hemiptera Corixidae + + a + a a jCorixa panzeri + 0 Callicorixa praeusta + Sigara dorsalis + a i S. concinna + a 0 S. stagnalis + + a + +

I Notonecta viridis + + + + 0

i I I Coleoptera + *Colymbetes fusers C

Enochrus bicolor + I *Graptodytes granularis Noterus clavicornis + C 0 1 - + o - DipteralChironomidae + a !Ephynidae pupa 0

+ = present; o = occasional; c =common; a = abundant; F =fyke net. r = Stations notknown July and October 1996. Table 1.2.1. cont. Fauna Recorded atLady's Island Lake, Co. Wexford. ( ) = records for July

t

Stations(L.T. = light trap) , ' Fauna ----_--'------D L.T.D': E L.T.E -- - - A !L.T. B -L_T.B C L.T.CI- - - i Mollusca _ - _ -- j + o + o c20 Prosobr100 ,_ rt_ f c20 i Hvdrobia ventrosa 8 o iPotamopyrgusantipodarum 12 + Pulmonawi_ _------'- fi Opisthobranchia _ - shells - Bivalvia: Cerastodermaglaucin shells! shellsi J ; + + Bryozoa Conopeum seurati + Echinodermata j Tunicata __-

Ascidia ' F,5 I F,13 Teleostei lAnguilla anguilla F, 5 Gasterosteus aculeatus + c50 o 1 l o a o + I Mugilidae F1,17 F1,7 F2,6 F4,5 jPlatichthys flesus A F,3t Pollachius pollachius a a 3 I Pomatoschistusmicrops a >100 + 14 Spinachia spinachia F, 1 ISprattus sprattus SvnQnathus acus J

J

i

+ = present; o =occasional; c = common; a = abundant;F = fyke net. u

Lady's Island Lake rJ

Station E (OS 0989 0483) was located in the southeasterncorner of the lake close to cJ the barrier and the location of annual breaching. Substrate consistedof coarse sand with large granite boulders, water depth varied from 0-80 cmand salinity measured 25%0. cJ Fauna The species recorded at the different stations, using all samplingmethods, are listed in D Table 1.2.1 Among 38 taxa recorded, 35 are identified tospecies. Four of the species are marine, 6 are poly-mesohaline, 13 are euryhaline, 4 areoligo-mesohaline, and 6 are limnic (Table 1.2.2). Eight of the species are listed aslagoonal specialists in Britain Ei (Davidson et al. 1991). Benthic fauna was probably under sampledand rough weather during sampling of D and E may have made collectingless efficient than at A and B. Ei Differences between stations reflect a N-S gradient in marine influencewhich is also demonstrated by differences in salinity. Some limnic and low salinity(oligo- mesohaline) species such as Sigara dorsalis, Sigara concinna, Notonecta viridis, Ei Noterus clavicornis, Enochrus bicolor, Potamopyrgus antipodarum and Ischnura elegans were confined to stations A and B at thenorth end of the lake and C (Bunargate Pool) but some others normally associated with low salinitywere found 0 near the barrier e.g. Corixa panzeri and Callicorixa praeusta. Highsalinity (poly- mesohaline) species e.g. Praunusflexuosus and Crangon crangon, were absent fromA and C. Reasons for the absence of Neomysis integer, normallya euryhaline species, EJ from A and B in October are not known. Severalspecies which were widely distributed in the lake were absent from C, including Balanusimprovisus and Conopeum seurati which were limited by the absence of rocksor other hard substrate, 0 and Idotea chelipes and Hydrobia ventrosa which were probably limitedby the low salinity. Gammarus zaddachi was the only completely aquatic amphipod presentin the lake. D No live Cerastoderma glaucum were found although shells were plentiful.The species was recorded in 1971 by Boyden and Russell (1972) andin 1976-77 by Healy et al. EJ (1982) and a thriving population has been observed on severaloccasions since e.g. in 1991 (Galvin 1992). The population is known to undergo widefluctuations in density. EJ Table 1.2. 2Ecological categories of the recorded taxa. L = lagoonal specialist according to (Davidson et al. (1991). a Marine Pollachius pollachius Spinachia spinachia Sprattus sprattus 0 Syngnathus acus

Poly-mesohaline Arenicola marina 0 Balanus improvisus Praunusflexuosus Crangon crangon 0 Hydrobia ventrosa L Mugilidae Euryhaline Hediste diversicolor 0 Neomysis integer Idotea chelipes L 0

7 0 Lady's Island Lake J

Table 1.2.2 (cont.) J Lekanesphaera hookeri L Gammarus zaddachi Palaemonetes varians L Carcinus maenas Sigara stagnalis L Conopeum seurati L Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps Pl atichthys Jlesus

Oligo-mesohaline Potamopyrgus antipodaruin Ischnura elegans Sigara concinna L J Enochrus bicolor L

Limnic Sigara dorsalis J Corixa panzeri Callicorixa praeusta Colymbetes fuscus J Graptodytes granularis Noterus clavicornis

1.2.3Discussion J A typical lagoonal fauna was present with elements of bothlow and high salinity faunas. There was little evidence ofa recent invasion of marine species, suggesting that early closure of the breach this yearmay have limited the period of tidal flow sufficiently to prevent extensive colonisation. It is possible,too, that the unusually early date of breaching (April is themore usual month) meant that few individuals of marine species were present in inshore watersat the time, and almost no larval forms. Sprat, mullet, flounder and pollack breed in theopen sea and must therefore have entered the lake as juveniles or adults during tidal periodsfollowing breaching. Many other fish species, including herring and dogfish have been takenin the past. The lake fauna has, in the past, undergone wide fluctuationsin populations according to the changing salinity regime with corixids and becomingabundant and n diverse when the salinity fell below 10%o and fish andcrustaceans replacing them J during high salinity phases (Healy et al. 1982). Whensampled this year, the fauna appeared to be in an intermediate phase anda strong N-S salinity gradient was evident. The fauna was poor by comparison with 1977-78 whenmore than 58 species were recorded (Healy et al. 1982). In thatyear, extensive tidal exchange brought in a wide range of marine species which coexisted with a low salinityfauna that had become established during the previousyear. Galvin (1992) recorded 49 taxa in the lake (including the Bunargate Pool), including 9 lagoonal specialists.A total of 97 macrofaunal species has been recordedover 17 years of observations (unpublished). According to Southwood and Leston (1959) Notottecta viridiswas only reported for Wexford and north Kerry. It has since been recordedat this site by Healy el al. (1982) r u

8 Li

Lady's Island Lake 0

and by Galvin (1992). It was found at Tacumshin L.,Kilkeran L. and L. Donnell during this survey. 0

1.2.4Threats 0

Land reclamation. Wexford County Council has granted planning permission for extension of a pitch and putt course which would encroachon an area subject to 0 winter flooding. Development of the flood zone by importation oflandfill will reduce the area of important shallow water habitats. As the areaof Lady's Island Lake varies 0 considerably according to season and rainfall, it is important thatthe boundary of any designated protection area be drawn to take this into account. Pollution. Serious eutrophication was first noticed in the early 1980swhen 0 phytoplankton blooms became common. The main sources of nutrientsare believed to be fertilizer, silage, and slurry runoff from surrounding land, andpossibly sewage overflow from a new housing estate near the north endof the lake. 0 Gravel extraction. Illegal extraction of gravel from the barriernear Carnsore continued until quite recently. As the supply of sediment tothe beach has been steadily 0 diminishing, removal of existing material may add to erosion problemsin the area and may also be responsible for the failure in recent yearsfor the breach to seal as rapidly as it formerly did. a

Breaching. Breaching is seen as a threat to the importanttern colonies because when the outlet remains open for long periods the water levelfalls below a critical level 0 allowing mammalian predators to reach the islands. Breaching is alsoseen by many as a threat to aquatic life because it can result inhigh mortalities of flora and fauna. The lake may even appear "dead" after an extended period oftidal flow. However, long- 0 term studies (unpublished) have shown that the community recovers withno obvious loss of species a 1.2.5Evaluation a Lady's Island Lake is a large, natural sedimentary lagoon andis therefore of international importance based on geomorphology. It isone of the largest and possibly the best example of a true lagoon in the wholeof Europe. It is also of international El importance for its ornithological valueas a breeding site for endangered tern species. The site is rated as of international geomorphological importance andthe sole 0 surviving major example in Ireland ofa back-barrier seepage lagoon. The sequence of back-barrier washover and seepage structuresare among the best examples in Europe (Orford and Carter 1982). 0 The aquatic faunal community during stable periods comprisesa characteristic assemblage of brackishwater species, a high proportion of whichare specialist lagoonal species. A strong N-S salinity gradient and a wide rangeof substrate types explains the 0 high level of species richness reported in this and othersurveys. This is not always apparent, however, because the community undergoes wide fluctuations in species composition and abundance due to breaching. 0

a 9 0 Lady's Island Lake

Among other important features of Lady's Island Lake are itslarge size (few lagoons in Britain are more than 10 ha), its naturalness, andits long history of scientific investigations. This is the best documented lagoon in Ireland andscientific studies are ongoing. Of particular interest are local geomorphological processes and theeffects of the fluctuating conditions on fauna and flora. Current management practices are controversial and effective solutions to the conflicting interests are subject to financial constraints. The lake is a Refuge for Fauna, an SPA anda proposed NHA (Site Code No. 704).

In conclusion, Lady's Island Lake is regarded as of exceptionalconservation value and highly recommended as a proposed SAC.

1.2.6References and Additional Sources J Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department J Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. J Bates, R. 1977 An ecological survey of a brackish lagoon. Our Lady's Island Lake, Co. Wexford. Unpublished thesis, University College, Dublin. Boyden, C.R. and Russell, P.J.C. 1972 The distribution and habitatrange of the J brackish water cockle (Cardium (Cerastoderma) glaucum) in the British Isles. Journal of Ecology. 41: 719-734. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Carter, R.W.G. and Orford, J.D. 1980 Gravel barrier genesis andmanagement: a contrast. Proceedings, Coastal Zone 80, American Society of Civil Engineers J 1304-1320. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. J Davidson, N.C. et al.1991. Nature conservation and estuaries in . Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Galvin, P. 1992 The ecology of the brackish-water lagoons ofWexford and East Cork. M.Sc thesis, University College, Dublin J Healy, B., Bates, R. and McGrath, D. 1982 Marine Faunaof Co. Wexford - 5. Lady's Island Lake. Irish Naturalists' Journal 20: 509-560. J Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hurley, J.1994 The South Wexford Coast, Ireland - a natural heritagecoastline. Telecom Eireann, 31 pp. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979. Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. J

10 Lady's Island Lake 0

Lowry, P. and Carter, R.W.S. 1982 Computer simulation and delimitationof littoral power cells on the barrier coast of southern C. Wexford,Ireland. Journal of Ei Earth Sciences of the Royal Dublin Society 4: 121-132. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 0 1, Bord Failte/ An Foras Forbartha. Merne, O.J. 1974. A Guide to the Birds of Wexford.South East Tourism and Bord Failte. 49 pp. 0 Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Murphy, P. 1956 Our Lady's Island, Wexford, in history andlegend. The People 0 Newspapers, Wexford. 32 pp. Norton, M. and Healy, B. 1984 Marine fauna of CountyWexford - 7. Observations on the ecology and reproductive biology of Sphaeroma hookeri Leach (Isopoda). 0 Irish Naturalists' Journal 2: 25 7-262. Orford, J.D. and Carter, R.W.G. 1982 Geomorphological changes on thebarrier coasts of South Wexford. Irish Geography 15: 70-71. E Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis. Dublin University. 0 Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the 0 Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp. 0 Ruz, M-H. 1989 Recent evolution of the southeast barrier coastof Ireland. Journal of Coastal Research 5, 523-539. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. 0 Southwood, T.R.E and Leston, D. 1959. Land and water bugsof the British Isles. Wayside and Woodland series. Warne and Co., London. 446 pp. 0

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Plate 9.2-1 View of the breach in the barrier ofLady's Island Lake, 1 st July 1996. me

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r Plate 1 ,2.2 View of the northern area of Lady'sIsland Lake, Station A. go

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Plate 1. 2.3 View of the area to the eastof Lady's Island Lake, Station B. a

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Plate 1. 2.4 View of the southwest area of Lady'sIsland Lake, Station D. r r40

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a Plate 1 1..5 View of the southeast area of Lady'sIsland Lake, Station E is 0

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Plate 12-6 Large granite boulder at Station E of Lady'sIsland Lake, showing dense zone of Balanus improvisus, taken in the 1980's. Lady's Island Lake

J 1. 3 VEGETATION SURVEY Pat Hatch, Sherkin Island Co. Cork

Aims

J The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

UI 1.3.1Site Description nI This large lagoon is bordered by low-lying, predominantly pastoral farmlandto the J north, east and west. The barrier lies to the south.The major freshwater inflow joins the lake at its northern extent.

The main features of the shoreline, including marginal communities, areshown in Fig. 1.3.1. The slope of the shores is generally shallow. Marginalswamps occur in more 7 or less sheltered areas with long stretches of open shoreelsewhere. In these areas U marginal vegetation forms a typically narrow strip. There is anarea of open rocky shore in the south east. Extensive marshland occurs at RingMarsh in the south eastern quarter.

There is a semi-isolated pool in the south west ofthe site fringed by emergent swamp species.

1.3.2 Methods

This site was surveyed using transects only. The locality ofthese is shown in Fig. 1.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the n adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves J and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was J dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. Theaverage height and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

I lJ At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel 7 survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic LJ survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. J

12 u

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- Swa m p 0 Dowiihant species oode5:

[.U9+rd(t 5 PaQ12-pirCITAI i"e 5 0 5mdY - Jc*trpLt5 wiari-''m.(5 51dc-5c-hoevlop!ec a5(dcL454; 55p. E

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Fig. 1.3.1 Lcl V,s15(and l ike, Go Wexford - Swctmi2 \1tgefafioh O

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Fig. 1.3.2 Lady's Island Lake, Co.Wexford: Location of Transects J

7 Lj u

Lady's Island Lake 0

E At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many 0 metres out from the shore. For the purposes of thissurvey, `the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and 0 the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0

In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was 0 generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded. 0 Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the transect. a Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) 0 methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: D Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin D scale as follows:

Domin. 10 91-100% a 9 76-90 % 8 51-75 % 7 34-50 % 0 6 26-33 % 5 11-25 % 4 4-10 % a 3 <4 % -many individuals 2 <4 % -several individuals 0 1 <4 % -few individuals

Frequency Values 0 Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100% 0 IV 61-80 % III 41-60 % 0

13 J

J Lady's Island Lake

II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each J community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). J Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS

14

I i U

Lady's Island Lake a

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous 0 green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. a Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0 Nomenclature

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0

Evaluation C This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey. D The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen 0 algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. n A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey. 0 A `Not Valuable 'site is one that is shown tobe of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see 0 `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged. 0

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15 G rl J Lady's Island Lake

J 1.3.3Results n J Transect tables Site: Lady's Island Lake Transact code: A 7 J Location: Roc shore near outlet Sample point: 1 Aquatic - 10m out - granule Sample area: Granule only Substrate: Sand,ravel, boulders

Depth: 80 cm + Salinit : 23arts per thousand NBC communit :----- Height (cm) Cover (%)

Ruis s p. 40+ n Filamentous algae u Description:

J

Site: Lady's Island Lake Transact code: A Location: Rocshore near outlet Sample point: 2 Aquatic - 3m out Sample area: 16m2 4x4 Substrate: Sand,ravel, boulders

Depth: 50 cm Salinit : 23arts per thousand

NBC communit : ----- n Height (cm) Cover (%) Total Plant < 1 U

Ruis s p. 15 < 1

Bare substrate 100 rl J Sand and ravel 90 Boulders 10

Description: Very sparse low growing Ruis only.

16 Lady's Island Lake 0

Site, Lady's Island Lake Transact code: A Location: Rock shore near outlet Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Sand,ravel boulders

Depth.- 0 cm Salinit : ----- NBC communit :Undetermined Height cm Cover %) Total Plant 75

Juncus Gerald 30 25 A rostis stolonifera 20 25 Festuca rubra 20 5 Potentilla anserina 10 5 Glaux mantima 10 5 Aster tri olium 40 10 S er ularia marina 8 < I 0 Atri lex hastata 4 < I Tri leuros ermum maritimum 5 < 1 0 Planta o corono us 4 < I Juncus bufonius 4 < I Isole es cernua 5 < I

Bare substrate 25 r,

L.J Sand and ravel 5 Boulders 20

Description: Juncuserardii - A rostis stolonifera dominated shore community forming 15m wide strip amongst scattered boulders. 0 Grading to Dact lislomerata - Festuca rubra grassland.

E

0 Site. Lady's Island Lake Transect code: B Location: Outlet to sea Sample oint: 1 Aquatic - 5m out - grapnel 0 Sample area: Grapnel only Substrate: Sand,ravel

Depth: 80 cm + Salinit : 23arts per thousand NVC communit : ----- 0 Height (cm) Cover (%)

Ruis s p. 40 cm + 0 Filamentous algae

Description- 0

0 17 J

Lady's Island Lake

J Site: Lady's Island Lake Transect code: B Location: Outlet to sea Sample oint:2 Aquatic - 5m out Sample area: 16m2 4x4 Substrate: Sand,ravel

Depth: 80 cm Salinit : 23arts per thousand NVC communit :----- Height (cm) Cover Total Plant < I

Enteromor ha < I

Description: Very sparse Enteromor ha only.

Site: Lady's Island Lake Transect code: B Location: Outlet to sea Sample point: 3 Marginal J Sample area: 16m2 8x2 Substrate: Sand,ravel

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 15

Atri lex hastata 2 5 S er ularia marina 6 < 5 Tri leuros ermum maritimum 3 < 5 Senecio jacobaea 6 < 5 Atri lexatula 2 < I

Description: Sparse community of mostly prostrate pioneer shorespecies forming 2mstrip. Backing unve etated sand and ravel for 20m. r, Backing to Ammo hila arenaria dune grassland. u

J

18 Lady's Island Lake

Site: Lady's Island Lake Transect code: C

Location: Western end of barrier Sample oint: 1 Aquatic - 10m out Sample area: 16m2 4x4 Substrate:Sand andravel

Depth: 60 cm Salinit : 23arts per thousand NVC communit :----- Height (cm) Cover %) Total Plant 80 Higher Plant 75

Ruis s p. 15 75

Algae 5

Lam rothamnium a ulosum 10 5

Description: Extensive low growing Ruis dominant. Lam rothamnium blackened and dead looking. Same species at more or less same coverfrom c.20m out to shore.

Site: Lady's Island Lake Transect code: C Location: Western end of barrier Sample oint: 2 Marginal Sample area: IOm2 10x1 Substrate: Sand andravel

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height (cm) Cover (% C Total Plant 10

Atri lex hastata 5 5 Tri leuros ermum maritimum 3 5

Salicornia a . 6 < 1 C Planta o maritima 4 < 1

0 Description- Im wide strip of sparse pioneer shore vegetation. 0

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19 Lady's Island Lake

Site: Lady's Island Lake Transect code: C Location: Western end of barrier Sample point: 3 Marginal Sam le area: lOm2 (5x2 Substrate: Sand,ravel

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover (%) Total Plant 20

J Suaeda maritima 10 5 Atri lex hastata 5 < 5 Tri leuros ermum maritimum 3 < 5 Aster tri olium 10 < 1 Glaux maritima 5 < I S er ularia marina 6 < I Cochlearia an lica 4 < I Planta o corono us 4 < I

Description: Sparse cover of low growing salt-tolerant shore vegetation withSuaeda the dominantspecies. 3m strip. Grading through Tri leuros ermum dominated community 10m to Ammo hila arenaria dunes (barrier).

Site: Lady's Island Lake Transect code: D

Location: Semi-isolated pool Sample point: 1 Aquatic - 3m out rl Sample area: 16m2 4x4 Substrate: Silt u Depth: 50 cm Salinit : 5arts per thousand

NVC communit : ----- 7 Height cm Cover (%) u Total Plant 80

Potamo etonectinatus 30 80

Description: Dense Potamo eton ectinatus in single species stand.

u

20 Lady's Island Lake 0

Site: Lad 's Island Lake Transect code: D 0 Location: Semi-isolated pool Sample oint: 2 Marginal Sample area: 80m2 10x8 Substrate:Silt 0 Depth: 0 - 40 cm Salinit : 5arts per thousand

NVC communit : S21 Scir us maritimus swam - Scir us maritimus sub-community Height cm Cover (% 0 Total Plant 90

Scir us maritimus 130 90 Potamo etonectinatus 30 < 1 0 Description: Dense Scir us maritimus swam with sparse Potamo etonectinatus the only associated submer ent species. 8m. 0 Scir us lacustris sstabernaemontani and Phra mites australis also forming single species and mixed species swamps in marginal areas ofpool . G

0

Site: Lady's Island Lake Transect code: D Location: Semi-isolated pool Sample point- 3 Marginal C Sample area: 16m2 4x4 Substrate: Depth: 0 cm Salinit : ----- 0 NVC communit : Undetermined Height cm Cover (%) Total Plant 100

Juncuserardii 25 20 A rostis stolonifera 20 75 Festuca rubra 20 15 Potentilla anserina 10 15 Leontodon autumnalis 25 < 5 Glaux maritima 10 < 5 Oenanthe lachenalii 30 < 1

Description: Complete round cover of Juncuserardii - A rostis stolonifera dominated community. 20m. Grading to A. stolonifera - Festuca rubra- Potentilla anserina grassland.

21 J

Lady's Island Lake

Site: Lady's Island Lake Transect code: E Location: Freshwater inflow Sample point: 1 Aquatic - IOm out Sample area: 16m2 4x4 Substrate: Silt and sand

Depth: 70 cm Salinit : 14arts per thousand NVC communit :----- Height cm Cover Total Plant 80 Higher Plant 60

Ruis s p. 40. 60 J

Algae 40

Filamentous algae 40

Description: Fairly dense Ruis bed. More or less unchanging cover back to marginalzone. Approximately 80% of Ruis plants in this sample were blackened and dead looking or partly so. J

Site: Lady's Island Lake Transect code: E Location: Freshwater inflow Sample point: 2 Marginal Sam le area: 100m2 10x10 Substrate:Silt and sand

Depth: 40 cm Salinit : 10arts per thousand NVC communit :S21 Scir us maritimus swam- Scir us maritimus sub-communit Height cm Cover (%) Total Plant 50 Higher Plant 40

Scir us maritimus 70 40 Ru is s p. 30 < 1

Algae 10

Enteromor ha 10

Description: Open Scir us maritimus swam with sparse Ru is and Enteromor ha. 20m-

rl J

22 v

Lady's Island Lake 0

a

Site: Lady's Island Lake Transect code: E 0 Location: Freshwater inflow Sample point: 3 Marginal Sample area: 100m2 (10x10 Substrate: Silt (de-oxygenated)

Depth: 30 cm Salinit : 6arts per thousand 0 NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - S.lacustris ssp tabernaemontani sub-community Height (cm) Cover %) Total Plant 60 Higher Plant 60

Schoeno lectus lacustris sstabernaemontani 100 40 Scius maritimus 70 20 0 Algae < 5 0 Enteromo ha < 5

0 Description: Fairly open swam vegetation wit h Schoeno lectus dominantover S . maritimus. Sparse free-floating Enteromoha. 30m. 0

0

Site: Lady's Island Lake Transect code: E 0 Location: Freshwater inflow Sample point: 4 Marginal Sam le area: 100m2 10x10 Substrate: Silt (de-oxygenated)

Depth: 15 cm Salinit : 0arts per thousand 0 NVC communit :S21 Scius maritimus swam- A rostis stolonifera sub-communit Height (cm) Cover (%) Total Plant 100 0

f1 Scir us maritimus 160 95 u A rostis stolonifera 40 10 A ium nodiflorum 25 < 1 Lemna minor < 1 G

Description.- Tall dense Scir us maritimus swam withsparse A rostis cover. 50m. 0

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23 a Lady's Island Lake

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Site: Lady's Island Lake Transect code: E Location: Freshwater inflow Sample point: 5 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 5 cm Salinit : 0arts per thousand

NVC communit : S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover %) Total Plant 100

Phra mites australis 300 100 Lemna minor < 1

Description: Tall, very dense Phra mites swamp. 100m. Grading to willow carr strip of c.50m width. Backing pasture. a

J Site: Lady's Island Lake Transect code: F Location: Exposed promontory head Sample point:1 Aquatic - IOm out Sample area: 16m2 4x4 Substrate: Gravel, cobbles

Depth: 70 cm Salinit : 22arts per thousand NVC communit :----- Height cm Cover Total Plant 5

Ruis s p. 40 5

Substrate

Cobbles 80 ri Gravel 20

L-1

Description: Sparse Ruis only.

24 Lady's Island Lake a

Site: Lady's Island Lake Transect code: F 0 Location: Exposed promontory head Sample point: 2 Marginal Sample area: 16m2 4x4 Substrate: Sand Depth: ----- Salinit : ----- 0 NVC communit :Undetermined Height (cm) Cover %) Total Plant 100 D

Juncuserardii 30 80 0 A rostis stolonifera 15 10 Festuca rubra 15 5 Potentilla anserina 10 5 0 Glaux maritima 10 5 Aster triolium 30 < 1 Leontodon autumnalis 15 < 1 0 Tri leuros ermum maritimum 15 < 1 S er ularia marina 10 < 1 Atri lexatula 8 < 1 C Planta o major 6 < 1 0 Description. Extensive Juncuserardii cover with A rostis stolonifera and Festuca rubra locally co-dominant in small areas of more o pen Juncuscover. Associated sp ecies more or G less sparse. 20m. Backing to Rubus fruticosus - Salix fra ilis hedgerow. Backing arable farmland. 0

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Lady's Island Lake

J Site: Lady's Island Lake Transect code: G Location: Sheltered bay Sample point:1 Aquatic - 5m out Sample area: 16m2 4x4 Substrate: Silt, sand,ravel

Depth: 50 cm Salinit : 21arts per thousand NVC communit :----- Height (cm) Cover rl Total Plant 70 j Higher Plant 60

1 Ruis s p. 40 60 J Algae 10

Filamentous algae 10 Lam rothamnium a ulosum 8 < 1 J Description,- Patch cover of dominant Ruis with filamentous algae ands arse Lam rothamnium. Fruiting Ruis plantsresent. Lam rothamnium blackened and dead- looking. Grapnel surveys from 5 - 50m out found no additionalspecies.

Site: Lady's Island Lake Transect code: G Location: Sheltered bay Sample point: 2 Marginal Sam le area: 100m2 10x10) Substrate: Silt

Depth: 30 cm Salinit : 18arts per thousand

NVC communit : S21 Scir us maritimus swam- Scir us maritimus sub-community Height cm Cover Total Plant 80

Scir us maritimus 100 80

Description: Fairly dense single species Scir us swamp. 45m.

26 Lady's Island Lake

Site: Lady's Island Lake Transect code: G Location: Sheltered bay Sample oinv 3 Marginal 0 Sample area: 100m2 10x10 Substrate: Silt

Depth: 15 - 30 cm Salinit : 10arts per thousand

NVC communit : S4 Phra mites australis swam - Phra mites australis sub-community 0 Height (cm) Cover %) Total Plant 100 D Phra mites australis 300 100 c Description: Tall dense single species Phra mites swamp. 30m. 0

D Site: Lady's Island Lake Transect code: G Location: Sheltered bay Sample point: 4 Marginal Substrate: Not known 0 Sample-area: 16m2 4x4 Depth: ----- Salinit : ----- NVC communit :Undetermined C Height (cm) Cover (%) Total Plant 100 G Juncuserardii 30 50 A rostis stolonifera 25 40 Potentilla anserina 20 20 0 Aster tri olium 40 5 Leontodon autumnalis 20 < 1 Glaux maritima 20 < 1

Description: Juncuserardii and A rostis stolonifera co-dominant, each locall y mono- dominant, among species-poor salt tolerant community. 20m.

Grading to A rostis stolonifera - Festuca rubra - Potentillaanserina grassland.

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27 0 Lady's Island Lake

1.3.4Evaluation

`Valuable'

This large site was surveyed by transects only. Therefore, theinformation available upon which to make this assessment is limited compared withmost other sites. Six transects were carried out at the lagoon and one ina semi-isolated pool in the south west of the site.

This is one of the three Irish sites at whichLamprothamnium papulosum had been recorded prior to this survey. This rare charophyte was foundin the course of this 1 survey at the western end of the barrier and ina sheltered bay in the north east corner. J Its presence alone qualifies this as a valuable site. Ruppia was found at all six lagoon transects, with acover of 50% or more at three of these, one in each of the two northern bays andone at the west end of the barrier.It is notable that both Ruppia cirrhosa and R.maritima occur here.

Potamogeton pectinatus was not found in the lagoon but wasabundant in the semi- isolated pool, which had a much lower salinity level (5parts per thousand) than the rl lagoon itself (14-23 parts per thousand). LJ Marginal vegetation does not seem to be of particular interesthere. Scirpus mantimus, Schoenoplectus lacustris ssp. tabernaemontani and Phragmites australis swamps all occur at this site, but are nowhere extensive. Juncus gerardiidominated salt tolerant community occurs on more open shores.

The basis for the designation of Lady's Island Lake asvaluable is the presence of Lamprothamnium papulosum and both Ruppia species and the apparent wide distribution of all these species.

Further survey is recommended.

28 J

J Lady's Island Lake

J 1.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork.

1.4.1 Site Description

Large coastal brackish lake with sand/pebble dune barrier, opened almostannually by artificial excavation to permit drainage of the lake (Healy etal. 1982). Lake shore near barrier with coarse sand, pebbles, cobbles and boulders. Margins inplaces with nutrient and organic matter enrichment from breeding, roosting and loafing birds. Marginalvegetation includes Scirpus maritimus, Juncus gerardi, Glaux maritima and Salicornia sp.Margin of barrier and breach with dry coarse sand.

J Subsites(see Fig. 1.4. 1)

1. Juncus erg ardiEast(T 100049) Dense to sparse zone of Juncus gerardi, Glaux maritima, etc.,with some grass-dominated patches, c. 1-4 m from water edge (summer) above emergentScirpus maritimus, on coarse sand and pebbles with organic content. Soil moist; surface-dry soil(further up shore) avoided for sampling.

7 2. Juncus gerardi West(T 099053) u Zone of dense vegetation with Juncus gerardi near bare orsparsely vegetated zone behind emergent stand of Scirpus maritimus.

3. Salicornia / bare sand (T 082053) Bare coarse sand area (c. 250 m2), exposed during summer,with sparse growth of Salicornia and small patches of denser vegetation including Juncus gerardi.

1.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes. J As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating thepresence of rare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

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0 Fig. 1.4.1 Map of sampling sites (Carabidae and Staphylinidae)at Lady's Island Lake, Co. Wexford

1 - Pitfall traps,S-vac 0 2 - Ground search 3 - Pitfall traps 0

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J Lady's Island Lake

Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

U Interpretation of Indicator Species

Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat J (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings

The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous r-t assemblages (e.g. Lepidoptera). Different indicator speciesare likely to occur in u spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based J on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites. U71 Sampling Strategy

At each site representative marginalareas were sampled, including vegetation dominated by Scirpus maritimus, Jtrncus maritimus, Jurrcus gerardi andgrasses, as well as bare or poorly-vegetatedareas of sand, silt or peat. Particular emphasis was given to habitat associated with the sedimentary barrier andareas of highest salinity, since much of the habitat associated with freshwater inflowsto the interior of the J lagoons would contain a soil fauna not dependenton coastal lagoons. n Sampling Techniques

The sampling methods used are listed in Table 1.4.1. Foreach site, a Stihlo BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as

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Lady's Island Lake 0

'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter 0 (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species 0 expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from the same type of plastic cups that were used for the traps themselves. 0

TABLE 1.4.1. Details of sampling methods.

0 Method Details No. replicates Sampling period, etc. per unit sample 0 Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and C plastic funnels; collars used where cattle/horses occur C Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth 0 burrow casts observed; agitated soil floated in water Ground search Search of bare soil (< 50% 1 1 hour 0 vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer J substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (I hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 0 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn (late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated 0 with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent. 0 Variety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by 0

31 0 J Lady's Island Lake

other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfall traps, especially as it is difficult to visit sites twice between spring tides to place and lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the J survey. However, this was planned for, and three sets (6 traps each) were placed at all sites (four sets at some sites), of which two were sorted. There was only one site rl (Aughinish which has a spring/neap water level variation of >I m) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the n National Museum of Ireland, and specimens of many of theother species have been retained in J the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv. :Mar. Freshw. Ecosyst. 2: 185-208. n Good, J. A. and Speight, M.C.D. (1991) Sites of internationaland national importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. J 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from (1) Juncus gerardi (East)- S-vac suction sampler (part 17 vii 1996, part 12ix 1996 (separate dates for subsamples due to engine fire on firstdate), c. 2 m2;

32 Lady's Island Lake

(2) Juncus gerardi (East) - 6 plastic pitfall traps with funnelsand ethylene glycol preservative (23 vi - 3 viii 1996); (3) Juncus gerardi (West) - 6 pitfall traps (22 viii -13 ix 1996),- (4) Salicornia / bare sand - 1 h ground search (18vii 1996). C No Bledius burrow casts were located, nor were Bledius foundin 12 flotation subsamples, at the above sampled areas.

Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated withthe lagoon margins; and, 0 (2) they are reported in the literature as being localor rare, from which it is assumed that they are less likely to survive in historically degraded ecosystems.

1.4.3 Results

Thirteen species of carabid and thirty-six species of staphylinid wererecorded, three species of which are regarded as indicator species (Table 1.4.2).

Although Atheta gyllenhali is not listed by Hyman and Parsons (1994) as being rare or notable in Great Britain, it appears to be local orrare throughout Europe (Palm 1970, Benick and Lohse 1974). Johnson and Halbert (1902) cite twoIrish records. The species is 0 stenotopic, restricted to marshes, alder carr and bogs (Koch 1989).

There is only one previous Irish record ofAtheta liliputana (PollardstownFen. Co. Kildare) 0 which is cited as rare in Scandinavia and Central Europe(Good 1994). The species may be associated with birds (carrion, faeces, etc.), and is described asa stenoptopic woodland species by Koch (1989). However, it has been recorded from grassy salt meadow habitat by 0 Hansen et al. (1991), and it is possible that itmay be associated with the tern colony at this site. 0 Gabrius keysianus, also recorded from Kilkeran Lake, is a halobiontwater margin species (Koch 1989), widespread but local in England and Wales (Hyman and Parsons 1994), and generally local and mostly rare in western Europe (Horion 1965).It has been previously 0 recorded in Ireland (O'Mahony 1929). 0 TABLE 1.4.2Carabidae and Staphylinidae (Coleoptera) recorded from Lady's Island Lake. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0

Species No. individuals 0 Carabidae a Agonum marginatum (L.) 7 Bembidion varium (01.) 21

Bradycellus harpalinus (Scrv.) 1 Broscus cephalotes (L.) 2 Calathus fuscipes (Goeze) 4 Dyschirius glob osus (Host.) 60

33 0 Lady's Island Lake

J TABLE 1 (cont.)

r-T Dyschirius luedersi Wagn. 7 u cupreus Duft. I 1 Harpalus rufipes (Geer) 1 Loricera pilicornis (F.) 5 ri Pterostichus diligens (Sturm) 2 U Pterostichus niger (Schall.) 4 Pterostichus nigrita (Payk.) I 7 J Staphylinidae

Alianta incana (Er.) 1 1 Aloconota gregaria (Er.) 29 J Amischa decipiens (Sharp) 4

Astenus longelytratus Palm 1 Atheta amplicollis (Muls. Rey) 9 Atheta atramentaria (Gyll.) 5 Atheta elongatula (Grav.) 13 Atheta fungi (Grav.) 2 J A thetagraminicola (Grav.) 19 * Athetagyllenhah (Thoms.) 1 Indicator species * Atheta liliputana (Bris.) 1 Indicator species Atheta volans (Scriba) 15

Calodera aethiops Grav. 1

Carpelimus corticinus (Gray.) 1

Cypha laeviuscula (Mannh.) 1 J * Gabrius keysianus Sharp 3 Indicator species Gabrius nigritulus (Grav.) 1 Gnypeta carbonaria (Mannh.) 8

Megarthrus depressus (Payk.) 1 Ocypus olens (Mull.) 5 n Paederus fuscipes Curt. 13 Philonthus carbonarius (Grav.) 1 J Philonthus cognatus (Steph.) 1 Philonthus laminatus (Creutz.) 5

Philonthus quisquiliarius (Gyll.) 1

Quedius tristis (Grav.) 1

Sepedophilus nigripennis (Steph.) 1 Stenus boops Ljungh 4

Stenus canaliculatus Gyll. 71

J Stenus clavicornis (Scop.) 1 Stenus juno (Payk.) 32 Stenus melanopus (Marsh.) 3 Tachyporus chrysoinelinus (L.) 6

Tachyporus hypnorum (F.) 1 Tachyporus nitidulus (F.) 21 Tachyporus pusillus Grav. 3

J 1.4.4Evaluation

Of average conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

34 Lady's Island Lake

Scientific Argument for Rating

The presence of three indicator species indicatesan ecologically well developed site. However, further investigation of this large site is required beforeit can be rated as a whole.

1.4.5References

Benick, G. and Lohse, G.A. (1974) Staphylinidae II (Aleocharinae,Callicerini). In: Freude, H., Harde, K.W. and Lohse, G.A. (eds). Die Kdfer Mitteleuropas.5. Goecke & Evers, Krefeld. pp. 72-220. Good, J.A. (1994) Atheta liliputana (Brisout)(Coleoptera;Staphylinidae), a marsh beetlenew to Ireland. Ir. Nat. J. 24: 413. Hansen, M., Kristensen, S., Mahler, V. and Pedersen,J. (1991) Tiende tillaeg til "Fortegnelse over Danmarks biller" (Coleoptera). Ent. Meddr. 59: 99-126. Healy, B., Bates, R. and McGrath, D. (1982) Marinefauna of - 5. Lady's Island Lake. Ir. Nat. J. 20: 510-526. Horion, A. (1965) Faunistik der MitteleuropdischenKdfer. X. Staphylinidae: Paederinae bis . Feyel, Uberlingen-Bodensee. Hyman, P. S. and Parsons, M. S. (1994) A reviewof the scarce and theatened Coleoptera of Great Britain. Part 2. UK Nature ConservationSeries No. 12, Joint Committee for Nature Conservation, Peterborough. a - Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke& Evers, Krefeld. Lohse, G.A. and Lucht, W. H. (1989) Die KdferMitteleuropas. 12. 1. Supplementband mit Katalogted. Goecke & Evers, Krefeld. a Lucht, W. H. (1987) Die Kdfer Mitteleuropas.Katalog. Goecke & Evers, Krefeld. O'Mahony, E. (1929) Coleoptera. In: Praeger,R.L. (ed.) Report on recent additions to the 0 Irish fauna and flora. Proc. R. Ir. Acad. 39(B):22-36. Palm, T. (1970) Skalbaggar, Coleoptera.Kortvingar: Staphylinidae. Underfam. Aleocharinae (Atheta). Svensk Insektfaunano. 52: 117-296. 0

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35 Lady's Island Lake

1.5 SUMMARY AND EVALUATION

Lady's Island Lake is a large (c. 450 ha), naturalsedimentary lagoon and therefore qualifies for protection under the Habitats Directive. It is oneof the largest and possibly the best example of a true lagoon in thewhole of Europe. It is also of international importance for its ornithological value as a breeding sitefor endangered J tern species. The lake is a Refuge for Fauna, an SPA anda proposed NHA (Site Code No. 704). The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology Exceptional Aquatic Fauna High Vegetation High Ecotonal Coleoptera Average

Geomorphology Lady's Island Lake is a large, natural sedimentary lagoon, Itis one of the largest and possibly the best example of a true lagoon in thewhole of Europe The sequence of back-barrier washover and seepage structuresare among the best examples in Europe (Orford and Carter 1982). The lake is rated as of exceptional conservation value asone of the best examples of its type in Europe and for its large size, relativenaturalness and documentation. J Aquatic Fauna

A total of 38 species was recorded, of which 8were lagoonal specialists, the highest number for any of the 20 selected sites. In additionto lagoonal specialists, a large number of both limnic and marine species were also present,despite the fact that the survey was carried out late in the season (October) andweather conditions were poor. Interesting species included Notonecta viridis and Sigara concinna, the latteronly recorded from the south coast during this survey. J The large size of the lake (450 ha.), a strongN-S salinity gradient, regular breaching of the barrier and a wide range of substrate types explainsthe high level of species richness reported in this and other surveys. This is notalways apparent, however, because the community undergoes wide fluctuations in species composition and abundance due to breaching.

1 J 36 Lady's Island Lake 0

The lake is rated as of high conservation value forits high diversity, high proportion of lagoonal species and documentation.

Vegetation

This large site was surveyed by transects only. Therefore, theinformation available upon which to make this assessment is limited comparedwith most other sites. Six transects were carried out at the lagoon and one ina semi-isolated pool in the south west of the site. 0 Ruppia was found at all six lagoon transects, with acover of 50% or more at three of these. It is notable that both Ruppia cirrhosa and R.maritima occurhere. This is one of the 0 three Irish sites at which Lamprothamnium papulosum had been recordedprior to this survey. This rare charophyte was found in the course ofthis survey at the western end of the barrier and in a sheltered bay in thenorth east corner. Its presence alone qualifies this as a valuable site. Marginal vegetation does notseem to be of particular interest here. Scirpus maritimus, Schoenoplectus lacustris ssp. tabernaemontani and Phragmites australis swamps all occur at this site, but arenowhere extensive. Juncus C gerardii dominated salt tolerant community occurs on more open shores.

The basis for the designation of Lady's Island Lake asvaluable is the presence of Lamprothamnium papulosum and both Ruppia species and the apparent wide distribution of all these species.

Further survey is recommended

Ecotonal Coleoptera

Thirteen species of carabid and thirty-six species of staphylinid wererecorded, three species of 0 which are regarded as indicator species.

Although Atheta gyllenhali is not listed by Hyman and Parsonsas being rare or notable in 0 Great Britain, it appears to be local or rare throughoutEurope. There are two Irish records. The species is stenotopic, restricted to marshes, alder carr andbogs. There is only one previous Irish record of Atheta liliputana (Pollardstown Fen. Co. Kildare)which is cited as E rare in Scandinavia and Central Europe . The species maybe associated with birds (carrion, faeces, etc.), and is described as a stenoptopic woodland species.However, it has been recorded from grassy salt meadow habitat and it is possiblethat it may be associated with the tern colony at this site. Gabrius keysianus, also recorded fromKilkeran Lake, is a halobiont water margin species, widespread but local in England and Wales,and generally local and mostly rare in western Europe. It has been previously recordedin Ireland.

The site is rated as of avera e conservation valuefor terrestrial ecotonal community, due to the fact that the presence of three indicator species indicatesan ecologically well developed 0 site. However, further investigation of this large site is requiredbefore it can be rated as a whole. C

0 37 Lady's Island Lake

Summary

The lake is a very large, natural sedimentary lagoon, whichis still largely natural, although current management practicesare controversial and effective solutions to the conflicting interests are subject to financial constraints. The lagoon andbarrier are good examples of geomorphological types and there isa long history of scientific investigations. The lagoon is the best documented in Ireland andscientific studies are ongoing. Of particular interest are local geomorphologicalprocesses and the effects of the fluctuating conditions on fauna and flora. No particularlyrare species were recorded during this brief survey, but manyare "interesting" lagoonal specialists.

The lake is of great local importance and is ofimmense scenic value

J In conclusion, Lady's Island Lake is regardedas of exceptional conservation value and is highly recommended as n a proposed SAC. J

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38 J

COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

2. TACUMSHIN LAKE

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

J Prepared for the National Parks and WildlifeService

(BioMar/Life) J

J 2. TACUMSHIN LAKE J

CONTENTS

2.1 Study Area

J 2.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

2.2.1Methods 2.2.2Results 2.2.3Discussion 2.2.4Threats 2.2.5Evaluation 2.2.6References

2.3 Vegetation Survey J (Pat Hatch)

2.3.1Site Description 2.3.2Methods 2.3.3Results Transect tables 2.3.4Evaluation

2.4 Ecotonal Coleoptera J (Jervis Good)

2.4.1 Site description 2.4.2Methods 2.4.3Results 2.4.4Evaluation 2.4.5 References

J 2.5 Summary and Evaluation jn

J J 7 Tacumshin Lake J ri 2. TACUMSHIN LAKE, Co. Wexford J OS Grid Reference: T 050065. 1:50 000 Sheet No: 77 Alternative names: Tacumshane Lake

2.1 STUDY AREA

General features

Tacumshin Lake is a natural, brackish, percolating lagoon, situateda little over 1 km west of Lady's Island Lake and 14 km southwest ofWexford (Fig. 2. 1. 1).It lies behind a sand and gravel barrier which is at presentclosed but geomorphological J studies of the barrier, and a comparison of the 1840,1925 and recent maps, indicate that an outlet has existed intermittently at the westward endbut has shifted locality several times (Carter and Orford 1980, Ruz 1989). A naturaloutlet existed prior to 1972-73 when it became sealed by natural processes. At least four artificial outlets have been cut in thepast 100 years, all of which have been short-lived owing to rapid siltation by beach sand. In1975, a pipeline was installed through the barrier anda series of drainage channels excavated in the lake bed. Until the pipe became blocked in the late 1980s,the lake was generally dry in summer and filled with water in winter. In the lastfive years, flooding of arable farmland has created a need for amore reliable method of water level control. In summer 1996, six pipes were installed which drained the lakeexposing most of the substrate, but the pipes are not yet fully functional andat the time of faunal sampling (beginning of October) there was water toa depth of at least 1 in in the easternsector. The lake holds internationally important numbers of Brentgeese (Branta bernicla hrota) and nationally important numbers of 11 waterfowl species. Thelow water levels attract a diverse assemblage of waders including manyrare vagrants ( Sheppard 1993, Hutchinson 1994). The maximum waterfowlcount in the winter of 1994/5 was over 16,000 (Delany 1995). The lake is a proposed NHA (SiteCode No.00709) and proposed SPA. J Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) i The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 6.5°C in January and15°C in July. The growing season (the period of mean daily air temperatures above 6°C) is around 10 months and as snow and frosts are rare, some plant growthis possible in winter months. rl Annual rainfall is approximately 900 mm, and the number ofrain days (1 mm or more) J is <150. Winds are mainly from the southwest. Mean annualhourly wind speeds are 5.9 m/s and a maximum wind speed of 47 m/sis estimated to occur once in 50 years. The mean annual number of hours of bright sunshine is1700 which is the highest for the country. Mean relative humidity is around 85%as on all Irish coasts.

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0 Tacumshin Lake

Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, but inshore breakers rarely exceed 4.5 m withextremes reaching 8.5 m (Carter 1992). Maximum wave heights (averaging once in 50 years) are 18-20 in J (Couper 1984). Tides are semi-diurnal and the tidal range (MHWS-MLWS)at Rosslare is 3.1 m (Admiralty Tide Tables). Sea temperatures arelowest in February and highest in August.

Landscape and Geology A complex series of glacial deposits overlies a relatively flatLower Palaeozoic bedrock J (Carter and Orford 1982). Surface geology consists largely of tillderived from shales and slates, producing mostly wet mineral soils. Although situated closeto Lady's rl Island L., the underlying geology of Tacumshin L. is quitedifferent, producing a Lj shallow lake of finer, softer sediments. The area surrounding thelake is flat, consisting almost entirely of grazing or arable land.

Lake topography The lake is 3.5 km E-W by about 2 kmN-S. The total area of the lake as shown on the 6" map is approximately 450 ha but much of theformer bed is now taken over by reed beds and the area of open water, even in winteris much less. Sediments grade from soft sandy mud in the north to coarse, sandy gravelnear the barrier. There are few stones and no conspicuous rocks.

Geomorphology of the barrier Barrier systems extend uninterrupted for 12 km from Carnsore Pointto near Kilmore Quay. Early explanations for lagoon formation in the area suggestedthat they became isolated by westward migrating spits (Lowry and Carter 1981), butlater studies showed that the barrier on this part of the coasthas been, and still is, moving onshore by a "rolling-over" process rather than extending alongshore (Orford andCarter 1982).

The gravel-dominated barrier at Tacumshin is overlain with small aeoliandunes. It is divided into two distinct parts: Grogan Burrow in the eastis stable with a well- vegetated dune crest about 4 in high, while Mountpill Burrowin the west is lower with a sparsely vegetated crest of only 1-2 m (Orford andCarter 1984, Ruz 1989) (Fig. 2.1.2). A series of 53 washover fans has been identifiedwest of the drainage pipe, at intervals of 30-40 m, becoming closer toward the western endof the spit. Those in the eastern sector were no longer active in the mid 1980sbut overwash was frequent in the western sector (Orford and Carter 1984) (Fig. 2.1.2) Attempts toreduce overwash in this region by piling up beach sediments, planting marram grassand, more recently, by placing straw bales, have resulted in little accretion owing tothe scarcity of beach sand.

rl Sediments grade from fine grit to coarse sand, becoming finertoward the west where J the median grain size is 0.28 mm ( 2 4)(Ruz 1989). The fine sediments are associated with a gentle foreshore slope, formed in response to thelow wave energy of this sector. There appear to have been only short-term periods ofnet accretion on the western sector of the barrier and it has been suggestedthat its instability is due in part

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0 MHWS Protde AStable barrrei Prot le BActive overwash Profile CAggraded lake outlet 0 0 1------160 120 80 40 40 DISI AMC[ FROM MHWS (m) 0 Fig. 2.1.2 (a)Tacumshin Lake barrier. Profiles at three different areas. (From Orfordand Carter, 1984). 0

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TACUMSHIN LAKE BED (drrl Drainage da) cliff I culvert 0 e 9l at)td 0 ' BEACH FACE td Profile C BEACH FACE Profile 8 Profile A -t -

Mixed eolian & Fossil Stalk Active overwash withoccasional Fossiloverwash with low AcIM 0 beach sediment - wttl)h;7:: el vegetate d back banter seepage level back bafflerseepage o+anv "h ation in old lake back barrier It anrier outlet seepage 0 Fig. 2.1.2 (b) Tacumshin Lake barrier. Overwash sites along thewestern sector (Mountpill Burrow)., (From Orford and Carter, 1984). 0

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to human activities which interfere with natural barrier processes (Carterand Orford 1980).

Hydrology. The coarse sediments of the barrier allow extensive seaward seepagewhich is sufficient to prevent the formation of outlet streams. Their absenceis said to be characteristic of percolation lagoons.

The hydrological regime of Tacumshin Lake, even in the absenceof artificial drainage, is quite different from that of Lady's Island Lake because the geology is different. The average retention time for water is only 270 days comparedwith 2200 in Lady's Island n Lake and the seepage potential of the barrier is sometimesunable to cope with this so J that an outlet forms which may seal again during periodsof drought (Orford and Carter 1982). In the absence of an outlet/inlet, seawater enters the lake by both washover and also landward seepage streams, both occurring in thewestern sector. Freshwater enters by a number of small streams in thenorth and west and as runoff from surrounding land.

Water depth is probably never more than a metre or so except in a few areas in the east and in old or recently cut artificial channels. At present, the water level in the lake depends on the efficiency of artificial drainage. The six pipes recently installed should J allow sufficient water to accumulate in winter to support theimportant waterfowl population.

Salinity and water quality. Seawater at approximately 34%o enters thelagoon by percolation through the barrier, by seepage streams, by washover, andby salt spray being washed into the lagoon from the barrier. Salinities between0 and 26%o have been recorded in the lagoon as a whole (Galvin 1991,Healy unpublished). Temporary algal blooms sometimes occur following flooding after a period ofdrought but these are probably natural.

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Tacumshin Lake

2.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin J 2.2.1Methods

J Environmental variables The position of each sample area was determined using aGPS Personal Navigator ( Global Positioning Satellite, Garmin GPS 45). Manufacturers of theGPS state that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used J are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K. %o. precision). A photographic record was made of the site andlocal information sought concerning the background and recent history. Faunal Sampling. Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in the Zoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988)Faunal samples were preserved in 70% alcohol and stored for subsequent sorting andidentification. No fyke nets were used at this site as waterlevels were too low. Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of J the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of these were larval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for identification and these were often not available due to low population density and the limited number of individuals collected in the time available (e.g.hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify when preserved n (turbellarians, leeches). J

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Tacumshin Lake 0 All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same 0 species.

2.2.2Results EJ

The lake was sampled on l .vii.96 during the firstpart of the survey and from 1-3.x.96 during the more intensive survey. 0

Five sampling stations were selected in the lake to reflectthe influences of substrate, 0 freshwater and marine inflows. Positions of the sampling stations areshown in Fig. 2.2.1 0 Environmental Variables Station A (OS 0569 0666) was located in the northernshore of the lake (Plate 2.2.3) 0 where open water exists for much of the year. Substrateconsisted of silty sand, organic mud and occasional stones; water depth varied from 0- 60 cms., and salinity measured 8 %o. 0 Station B (OS 0345 0565) was located at the southwesternend of the lake in a deep drainage channel (Plate 2.2.4). Water depth varied from 0- 1.5 m in the area sampled, 0 substrate was sand, gravel and organic mud and salinity measured3-5 %o.. Station C (OS 0295 0542) was located at the southwesternend of the lake close to the barrier in what appeared to be the channel ofthe old outlet (Plate 2.2.5). Substrate 0 consisted of fine sand and silt with occasional smooth stones.water depth varied from 0 - 60 cms and salinity measured 18 %o . 0 Station D (OS 0599 0548) was located in the southeasterncorner of the lake close to the barrier. Substrate consisted soft organic mud and fine siltysand. Water depth was extremely shallow ( 0- 20 cms) and salinity measured 19%0. 0 Station E (OS 035 075 aprox.) was located in thenorthwest area of the lake where a road leads to the lagoon from Tomhaggard (Plate 2.2.6). Thisarea was sampled during 0 the first part of the survey (June) when salinity measured0 %o but was dry in October.

Fauna 0 The species recorded at the different stations, using all samplingmethods, are listed in Table 2.2.1. Among 40 taxa listed, 38 are identified tospecies. One of the species is poly-mesohaline, 7 are euryhaline, 8 are oligo-mesohaline, and 19are limnic. No live IJ marine species were recorded (Table 2.2.2). Six of the speciesare listed as lagoonal specialists in Britain (Davidson et al. 1991). Benthic species wereprobably undersampled and only small fish were collected because fyke netswere not used. 0 Differences between stations are explained by the wide variation insalinity and opportunities for colonisation from the sea. At C, where overwashand landward 0 seepage streams are frequent, Hydrobia ventrosa was present and thepresence of Pomatocerus tubes indicates direct colonisation from the sea in therecent past. However, corixids and notonectids were numerous at this site, includingmany limnic 0 species suggests that salinity at this station is often muchlower than 18%o. Both 0 5 0 :7 U U C-- j U C-] L] U U 08 Tomhaggard L] U U CJ U U U U U C-7 C-3 C- 07

06 05 Mountpill Burrow gravel barrier Grog.... an Burrow ------...... 02 Fig. 2.2.1 03 1 Location Map of Sampling Stations in Tacumshin Lake, Co. Wexford 04 1 05 1 06 1 07 1 U

Table 2. 2.1. Fauna Recorded at Tacumshin Lake, Co. Wexford.July and October, 1996 ( ) = records from July. 0

Fauna Sampling Stations ( L.T. = Tight-trap) A LT.A B L.T.B C L.T.C D E 0

Porifera i Cnidaria - _ __ Turbellaria ------i -- 0 Nemertea ------Annelida Hediste diversicolor c c + Pomatoceros lriqueter shell tJ Crustacea Ostracoda -- Copepods 0 Cirripedia Balanus improvises shells Mysidacea Neomysis integer 1 1 (c) 1 ri Isopoda Lekanesphaera hookeri c >100 + <100 c 2 (+) Asellus sp. (+) AmphipodaGammarus salinus + + + + + 0 Tanaidacea Decapoda Palaemonetes varians + ? a >100 c 2 Arachnids + 0 Insecta Thysanura Ephemeroptera rJ Odonata Ischnura elegans 1 + a Plecoptera (+) Trichoptera 0 HemipteraGerris odontogaster + G.thoracicus + Notonecta glaucum + + 0 N. viridis + + a Plea leachi + I Cori xi dae + a >100 a c loo a Callicorixa praeusta + + + c (a) Corixa punctata (+) (a) + + + + 0 C. panzeri L - Hesperocorixa linnaei + Sigara dorsalis a + + r -- (+) + Ej S. concinna - ----, +

S. stagnalis + a i a + ; a Coleopteta --- + + (+) a Colymbetes fuscus + --- - Enochrus halophilus +- --- - Gyrinus caspius + _ --- --_ ---- 0 Hydrobius forcipes - - (+) Hydroporous planes Hygrolus impressopunclatus + -- - _---_ ; ___-- 0 H. inaequalis + L-- ! i Laccophilres mtnutus ---' i + -- Noterus clavicornis + + I __ i. 0 Rhantes frontalis 0 + = present; o = occasional; a = abundant.

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Table 2. 2.1 cont.. Fauna Recorded at Tacumshin Lake, Co.Wexford. July and October, 1996 () = records from July.

Fauna Sampling Stations ( L.T. = Tight-trap) ALT.A B L.T.B C L.T.C D E DipteraChironomidae c + a + (+) Mollusca ------+ Prosobranchia Hydrobia ventrosa 5

Potamopyrgus antipodarum c 3 ; 1 1 (+)

Pulmonata Lymnaea peregra + j (+) L. palustris + Planorbis leucosioma - + (+) Opisthobranchia Bivalvia Cerastoderma glaucum shells Bryozoa Echinodermata Tunicata Teleostei Gasterosteus aculeatus a c loo + 15 a >100 ? (+) Pungilius pungitius I

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Tacumshin Lake 0

ragworm (Hediste diversicolor) and chironomid larvae were plentiful at Aindicating that if summer drainage had exposed the lake bed atthis station it was for a short period only. The presence of 12 limnic species at B,including 3 pulmonate snails and a fish, i.e. species with relatively low reproduction and dispersal rates,suggests that the salinity remains low at this station. 0 Shells of Cerastoderma glaucum were present at station A butno live specimens could be found. A thriving population was present in 1977 inan area of the southeast known 0 locally as the "cockle lake", and live specimenswere taken at station A in 1991 (Galvin 1992). tJ Table 2.2.2 Ecological categories of the recorded taxa in TacumshinLake L = lagoonal specialist according to Davidson et al. (1991).

Marine None

Poly-mesohaline Hydrobia ventrosa L EI

Euryhaline Hediste diversicolor Neomysis integer IJ Lekanesphaera hookeri L Gammarus zaddachi (salinus?) Palaemonetes varians L Sigara stagnalis L 0 Gasterosteus aculeatus Oligo-mesohaline Potamopyrgus antipodarum Ischnura elegans 0 Gerris thoracicus Notonecta viridis Sigara concinna L 0 Plea leachi Enochrus halophilus L Gyrinus caspius 0 Limnic Gerris odontogaster Notonecta glaucum Callocorixa praeusta 0 C. punctata C. panzeri Sigara dorsalis Hesperocorixa linnaei 0 Colymbetesfuscus Hydrobiusfuscipes Hydroporus planus 0 Hydrotus impressipunctatus H. inaequalis Laccophilus minutus Noterus clavicornis El Rhantus frontalis Lymnaea peregra L. palustris El Planorbis leucostoina Pungitius pungitius 0

0 6 a J

Tacumshin Lake

2.2.3Discussion The faunal assemblage of the lake as a whole ischaracteristic of lagoon waters with generally low to very low salinities but subject to occasionalinfluxes of seawater in confined areas of the system. The fauna at A andB was dominated by insects with beetles especially diverse. Station E, which held a range oflimnic species in July but was not intensively sampled, was completely dry at the beginningof October, thus the limnic element in the fauna may have been undersampled. According to Southwood and Leston (1959) Notonecta viridis was onlyreported for Wexford and north Kerry. It has since been recorded atthis site by Healy et al. (1982) and by Galvin (1992). It was found at Tacumshin L.,Kilkeran Land L. Donnell during this survey. Plea leachi and Gerris thoracicus were not recordedat any other site during this survey although both are regarded as slightly brackishspecies. Sigara concinna was described as rare in Ireland (Southwood and Leston1959) but was found also at Lady's Island L. and Kilkeran L. duringthis survey. Pungitiuspungitius is listed in the Irish Red Data Book (Whilde1993) as a "near threatened" species needing to be closely monitored.

J 2.2.4Threats The current flood-management scheme results in excessive drainage of thelake exposing extensive areas of the substrate, causing mortality of somefauna. Attempts to limit overwash are considered to be inappropriate bygeomorphologists.

2.2.5Evaluation

Tacumshin Lake is a large, natural sedimentary lagoon and istherefore of international importance. It is one of the largest and possiblythe best example of a true lagoon in the whole of Europe. It is also ofinternational importance for Brent geese and nationally important for 11 waterfowl species. The site is rated as of international geomorphological importance inspite of interference with natural processes. There is extensive documentation of the Tacumshin barrier morphology and processes. The aquatic fauna was rich with 40 taxa recorded ofwhich 7 are lagoonal specialists. Insects were abundant and Corixidae and Coleoptera were particularly diverseand include one rare backswimmer. The assemblage typifies a low salinitylagoon with a consistently high input of freshwater, and few opportunities for colonisationfrom the sea.

The lake is of outstanding ornithological interest and is aproposed SPA and a proposed NHA (Site Code 709).

In conclusion, Tacumshin Lake is regarded as of exceptional conservationvalue and highly recommended as a proposed SAC.

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Tacumshin Lake 0

2.2.6References and Additional Sources of Information 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department 0 Barnes, R.S.K. 1989a Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. 0 Boyden, C.R. and Russell, P.J.C. 1972 The distribution and habitatrange of the brackish water cockle (Cardium (Cerastoderma) glaucum) in the British Isles. Journal of Animal Ecology. 41: 719-734. 0 Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Carter, R.W.G. and Orford, J.D. 1980 Gravel barrier genesis andmanagement: a 0 contrast. Proceedings, Coastal Zone 80, American Society of Civil Engineers 1304-1320. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. 0 Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. 0 Galvin, P. 1992 The ecology of the brackish-water lagoons ofWexford and East Cork. M.Sc thesis, University College, Dublin. 0 Holmes, J.M.C. and O'Connor, J.P. 1988. A portable light-trap forcollecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 23 5-23 8. 0 Hurley, J.1994 The South Wexford Coast, Ireland - a natural heritagecoastline. Telecom Eireann, 3 1 pp. 0 Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. 0 Lowry, P. and Carter, R.W.S. 1982 Computer simulation and delimitationof littoral power cells on the barrier coast of southern C. Wexford,Ireland. Journal of 0 Earth Sciences of the Royal Dublin Society 4: 121-132. Merne, O.J. 1974. A Guide to the Birds of Wexford.South East Tourism and Bord Failte. 49 pp. 0 Orford, J.D. and Carter, R.W.G. 1982 Geomorphological changes on thebarrier coasts of South Wexford. Irish Geography 15: 70-71. Orford, J.D. and Carter, R.W.G. 1984. Mechanisms to account forthe longshore 0 spacing of overwash throats on a coarse clastic barrier insoutheast Ireland. Marine Geology, 56: 207-226. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp a Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 0 pp. Ruz, M-H. 1989 Recent evolution of the southeast barrier coastof Ireland. Journal of Coastal Research 5, 523-539. 0 Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. 0

8 0 J Tacumshin Lake

Southwood, T.R.E and Leston, D. 1959. Land and water bugsof the British Isles. Wayside and Woodland series. Warne and Co., London. 446 pp.

Whilde, A. 1993Threatened mammals, birds, amphibians and fish in Ireland. Irish Red Data Book 2. Vertebrates. HMSO, Belfast. 224 pp. J

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Plate 2.2.1 View of seaward end of drainage pipe runningthrough the barrier of i Tacumshin Lake. a

a

Plate 2,2.2 View of landward end of drainage pipe inthe barrier of Tacumshin Lake, showing drainage channels.

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D as

IN

a

Plate 2.2.3 View of the northeast area of Tacumshin Lake,Station A.

am

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Plate 2,2.4 View of southwestern area of Tacumshin Lake, StationB.

so 1

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Plate 2.2.5 View of southwestern area, near the barrier ofTacumshin Lake, Station C

Plate 2.2.6 View of northern area of Tacumshin Lake takenon 1 st. July, Station E

0 J Tacumshin Lake

2.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

2.3.1Site description

The surrounding landscape is fairly low-lying with pastoral farmland tothe north, east and west. The barrier lies to the south.

Several freshwater streams flow into the lagoon from the north.

The main features of the shoreline, including marginal vegetation, areshown in Fig. 2.3.1. Shores are generally shallow sloping and vegetated. Swamp vegetationoccurs in extensive stands in sheltered bays. Two bays in thenorth west of the site are almost entirely filled with emergent swamps, predominantly of Phragmites and 7 Schoenoplectus lacustris. More open shores occur on promontories in thenorth lJ central area, the north east and east.

2.3.2 Methods

This site was surveyed using transects only. The locality ofthese is shown in Fig. 2.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described. 9 lJ The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A rl transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic 7 survey due to water depth or poor visibility. Here, ofcourse, the results were a lJ species list only with no cover data. The reach ofthe grapnel was 10 metres.

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10 Key: Fig. 2.3.1 en 0-Oornindvnf 5wgwip 5recie5 Coc(ef: a a a a a a a a a a a a anyaF-nn a a a a a a a vea_e Sldc5md),Puu5 - 5cirrLls wlarus - 5r-hoevlopleofuS- 55r FkKc(//Mlfe5 (dc lOs Ki s a U U C._] C_] C-3 U 1_3 U U U U C_ 1 C-I C-] C_> C_3 U U C-I C r m N

H h Wu+c r Mark \ Ouflcf Pipe Fig. 2.3.2 Tacumshin Lake, Co. Wexford: Location of Transects 0

Tacumshin Lake a

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for 0 other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the 0 transect.

Representative examples of every marginal community encountered during the course 0 of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 6 26-33 % 0 5 11-25 % 4 4-10 % 3 <4 % -many individuals 0 2 <4 % -several individuals 1 <4 % -few individuals Frequency Values 0 Frequency of each species within the total number of samplesis expressed as follows: 0 Frequency V 81-100 % IV 61-80 % III 41-60 % 0 II 21-40 % 1 1-20 % 0

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7 J Tacumshin Lake

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Tall J Swamp communities were determined according to the NVC `Swamps and Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief M description covering dominant species, stand structure and physiognomy. cJ The locations of transects within each site were selected torepresent the degree of 7 variation therein. Variation in marginal zone floristics, aquatic floristics andshore and LA aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was LJ working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'.

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Tacumshin Lake 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this reportare in accordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of 0 Britain and Ireland: Stoneworts' (1992).

Evaluation 0

This section comprises a brief summary of the survey findings for each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of each site are species 0 composition, diversity and abundance, thepresence of rare species and whether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance isput on aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection. 0

A `Potentially Valuable'site is one which thissurvey indicates may be of interest and which may prove to be valuable following furthersurvey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-basedsurvey and not a full aquatic survey (see `Constraints') makes a complete assessment ofmany sites impossible. Further aquatic survey of sites where recommended is to be encouraged.

13 J Tacumshin Lake

2.3.3Results

Transect tables J Site: Tacumshin Lake Transect code: A Location: Barrier - Eastern end Sample point:1 Aquatic - 20m out Sample area: 25m2 5x5 Substrate:Silt, sand

Depth: 30 cm Salinit : 26arts per thousand NVC communit :----- Height cm Cover Total Plant 5

Ruis c.f maritima 15 5

J Description: Sparse low growing Ruis only.

Site: Tacumshin Lake Transect code: A Location: Barrier - Eastern end Sample point: 2 Aquatic - 1Om out Sample area: 25m2 5x5 Substrate: Silt, sand

Depth: 20cm Salinit : 26arts per thousand NVC communit :----- Height cm Cover Total Plant 40

Ruis c.f maritima 30 40

Description: Patch cover of Ruis only.

Site: Tacumshin Lake Transect code: A Location: Barrier - Eastern end Sample point: 3 Aquatic - 5m out Sample area: 25m 5x5 Substrate: Silt, sand

Depth: 10cm Salinit : 26arts per thousand

NVC communit : ----- Height cm Cover Total Plant 70

Ruis c.f maritima 30 70

Description: Increasing patchy Ruis cover.

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Tacumshin Lake 0

0 Site: Tacumshin Lake Transect code: A Location: Barrier - Eastern end Sample point: 4 Marginal Sample area: 16m2 8x2 Substrate: Sand 0

Depth: ----- Salinit : ----- NVC communit :Undetermined 0 Height cm Cover Total Plant 90 0 Juncuserardii 50 90 A rostis stolonifera 15 15 Glaux maritima 8 5 0 Aster triolium 40 5 Tri lochin maritima 20 < 1 Atri lexatula 4 < 1 0

0 Description: Tall dense cover of dominant Juncuserardii with patchy A rostis stolonifera among species-poor salt tolerant community. 6m. Backing open vegetation dominated b Tri leuros ermum maritimum and 0 Armeria maritima with sparse Planta o corono us. 10m. Grading to Ammo hila arenaria - Festuca rubra dune grassland(barrier). 0

0

Transect code: B Site: Tacumshin Lake 0 Location: Barrier - Seawater seepage point Sample point:1 Aquatic - 30m out Sample area: 25m2 5x5 Substrate: Silt, sand Depth- 40 cm Salinit : 35arts per thousand 0 NVC communit :----- Height cm Cover Total Plant 100 0

Ruis c.f maritima 40 100 0

-Description: Dense single species Ruis bed. Some plants in bud. This stand extends 0 20 - c.50m out.

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Tacumshin Lake

Site: Tacumshin Lake Transect code: B Location: Barrier - Seawater seepage point Sample oint: 2 Aquatic - IOm out J Sample area: 25m2 5x5 Substrate: Silt, sand Depth: 10 cm Salinit : 35arts per thousand NVC communit :----- Height (cm) Cover (%) Total Plant 5

Ruis c.f maritima 10 5

Description: Ruis now sparse and low growing. Same species at moreor less same cover 0 - 20m out.

Site: Tacumshin Lake Transect code: B Location: Barrier - Seawater seepage point Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Sand,ravel

Depth: ----- Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 50

Suaeda maritima 10 25 Glaux maritima 3 25 Salicornia agg. 2 < 1 S erlaria marina 3 < 1 Aster tri olium 6 < 1 Tri leuros ermum maritimum 4 < 1

Description: Suaeda and Glaux co-dominant among open species-poor salt tolerantshore community. 18m. Backing Ammo hila arenaria - Festuca rubra dune grasslandbarrier).

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Tacumshin Lake 0

Site: Tacumshin Lake Transect code: C 0 Location: Barrier - Outlet pipe Sample oint:1 Aquatic - 5m out Sample area: 25m2 5x5 Substrate: Silt

Depth: 40 cm Salinit : 30arts per thousand 0 NVC communit :----- Height cm Cover Total Plant < 1 0

Ruis c.f maritima 20 < 1 0

Description: Sparse fairly low growing Ruppia only. 0

0

0

Site: Tacumshin Lake Transect code: C 0 Location: Barrier - Outlet pipe Sample point: 2 Marginal Sample area: 20m2 10x2 Substrate: Silt 0 Depth: 0 - 40cm Salinit : 28arts per thousand NVC communit :S21 Scir us maritimus swam- Scir us manitimus sub-community Height cm Cover 0 Total Plant 100

Scir us maritimus 160 100 0

Description- Tall dense single species Scir us swam forming 3mstrip for 12m along shore. 0

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0 i

Tacumshin Lake

Site: Tacumshin Lake Transect code: C Location: Barrier- Outlet pipe Sample point: 3 Marginal Sample area: 20m2 10x2 Substrate: Sand,ravel

Depth: 0 cm Salinit : ----- NVC communit :S21 Scir us maritimus swam- A rostis stolonifera sub-community Height cm Cover Total Plant 100

Scius maritimus 90 20 J A rostis stolonifera 30 95 Glaux maritima 15 < 1

Description: Open Scius cover with dense A rostis stolonifera dominant below andsarse Glaux the only associated species. 3m. Backing Ammo hila arenaria dune grassland (barrier). J

Site: Tacumshin Lake Transect code: D

Location: Sheltered channel Sample point: 1 Aquatic - 8m out Sample area: 16m2 4x4 Substrate: Silt

Depth: 80 cm Salinit : 5arts per thousand

NVC communit : ----- J Height cm Cover Total Plant 100

Potamo eton ectinatus 50 100

J Description: Dense single species stand of Potamo etonectinatus extendin g from 5- 10m out. Width of channel c.40m.

18 a

Tacumshin Lake a

0 Site: Tacumshin Lake Transect code: D Sample point: 2 Aquatic - 2m out Location: Sheltered channel 0 Sample area: 16m2 4x4 Substrate: Silt

Depth: 60 cm Salinit : 5arts per thousand NVC communit :----- 0 Height cm Cover Total Plant 5 0 Potamo eton ectinatus 40 5 0 Description: Potamo etonectinatus now sparse, remaining mono-dominant. Cover more or less constant 0 - 5m out. 0

0

0 Site: Tacumshin Lake Transect code: D Location: Sheltered channel Sample point: 3 Marginal Sample area: 100m2 10x10 Substrate: Silt 0

Depth: 20 - 60 cm Salinit : 3arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - S.lacustrisssp 0 tabernaemontani sub-community Height cm Cover Total Plant 100 0

Schoeno lectus lacustris sstabernaemontani 140 100 0

Description: Dense single species S. lacustris swamp. 35m. 0

0

0

0

0

0

19 0 J

Tacumshin Lake

Site: Tacumshin Lake Transect code: D Location: Sheltered channel Sample point: 4 Marginal Sam le area: 100m2 10x10 Substrate: Silt

Depth: 0 - 20 cm Salinit : 3arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- Agrostis stolonifera sub-community Height cm Cover Total Plant 100

Schoeno lectus lacustris sstabernaemontani 140 80 Scius maritimus 120 10 A rostis stolonifera 40 50 Tri lochin maritima 70 10 J

Description: Fairly dense Schoeno lectus dominated swam with frequent Scius maritimus. A rostis stolonifera patchy below with frequent Trilochin. 40m.

Site: Tacumshin Lake Transect code: D Location: Sheltered channel Sample oint: 5 Marginal Sample area: 16m2 4x4 Substrate: Not known

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 100

Juncus erardii 40 50 A rostis stolonifera 30 40 Potentilla anserina 25 15 Glaux maritima 10 < 1 Aster triolium 40 < 1 Tri lochin maritima 50 < 1 Oenanthe lachenalii 40 < 1

J Description: Juncuserardii and A rostis stolonifera co-dominant with freq uent Potentilla and a few sparse salt tolerant associates. 25m. Backing flood embankment (height 3m, slope 45 degrees) with Festucarubra and Rubus fruticosus dominant. J Backing low lying Lolium erenne pasture.

20 J U

Tacumshin Lake 0

Site: Tacumshin Lake Transect code: E 0 Location: Marginal swam Sampleoint: 1 Aquatic - 40m out Sample area: 25m2 5x5 Substrate :Silt

Depth: 80 cm Salinit : 18arts per thousand 0 NVC communit :----- Heig ht cm Cover 0 Total Plant 100 Higher Plant 100 0 Potamo eton ectinatus 80 100

Algae 10 0

Filamentous algae 10 0

Description: Dense bed of Potamo eton ectinatus with s parsefilamentous algae. Same species at more or less same cover 20- c.45m out. 0

0

0 Site: Tacumshin Lake Transect code: E Location: Marginal swam Sample point: 2 Aquatic- 15m out Sample area: 25m2 5x5 Substrate: Silt 0

Depth: 50 cm Salinit : 18arts per thousand NVC communit :----- 0 Height cm Cover Total Plant 40 Higher Plant 35 0

Ruis c.f maritima 6 30 Potamo etonectinatus 25 5

Algae 10 0 Filamentous algae 10 Chara canescens 8 < 1 0

Description: Open cover of low growing Ruis dominant with s parse Potamo eton and 0 filamentous algae. Chara canescens very sparse. Same species atmore or less same cover 8 - 20m out. 0

0 21 Tacumshin Lake

Site: Tacumshin Lake Transect code: E Location: Marginal swam Sample point: 3 Aquatic - 5m out Sample area: 25m2 5x5 Substrate: Silt

Depth: 30 cm Salinit : 18arts per thousand NVC communit : J Height cm Cover (%) Total Plant 80 Higher Plant 80

Potamo etonectinatus 50 75 Ruis c.f maritima 20 5

Algae 5

Filamentous algae 5

Description: Potamo eton ectinatus dominant in fairly dense stand withsp arse Ruis and filamentous algae. Same sp ecies at more or less samecover 0 - 8m out. J

Site: Tacumshin Lake Transect code: E Location: Marginal swam Sampleoint: 4 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 0 - 30 cm Salinit : 14arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- Agrostis stolonifera sub-community Height cm Cover (%) Total Plant 100

Schoeno lectus lacustris sstabernaemontani 130 100 A rostis stolonifera 40 5

I Ll

Description- Dense S. lacustris swam with sparse A rostis coverincreasing to landward. I Om.

n 22 u u

Tacumshin Lake 0

Site: Tacumshin Lake Transect code: E 0 Location: Marginal swam Sample point: 5 Marginal Sample area: 100m2 20x5 Substrate: Not known 0 Depth: 0 cm Salinit : ----- NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- Agrostis stolonifera sub-community 0 Height (cm) Cover Total Plant 100 0 Schoeno lectus lacustris sstabernaemontani 100 30 Scius maritimus 80 20 A rostis stolonifera 30 90 0 Glaux maritima 15 < 1 0 Description: Open cover of dominant Schoeno lectus lacustris with abundantScius maritimus. A rostis stolonifera forming dense round cover. 8m. 0

0

Site: Tacumshin Lake Transect code: E 0 Location: Marginal swam Sample oint: 6 Marginal Sample area: 16m2 4x4 Substrate: Not known 0 Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover 0 Total Plant 100

A rostis stolonifera 40 80 0 Juncuserardii 40 20 Festuca rubra 30 10 Potentilla anserina 15 10 0

Description: A rostis dominant in dense cover with patchy Juncuserardii and frequent Festuca rubra and Potentilla anserina. 15m. Backing arable farmland. 0

0

0

0 23 0 J

Tacumshin Lake

Site: Tacumshin Lake Transect code: F Location: Freshwater inflow Sample point:1 Aquatic - 10m out J Sample area: 16m2 4x4 Substrate: Silt

Depth: 60 cm Salinit : 13arts per thousand NVC communit :----- Height cm Cover Total Plant 80

Potamo etonectinatus 50 80

Description: Fairly dense single species Potamo eton ectinatus bed. Samespecies at more or less same cover 0 - 12m.

Site: Tacumshin Lake Transect code: F Location: Freshwater inflow Sample point: 2 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 40 cm Salinit : 10arts per thousand NVC communit :S21 Scius maritimus swam - Scius maritimus sub-community Height cm Cover Total Plant 90

Scir us maritimus 120 90

Description- Dense single species Scir us swamp. 120m.

J

24 u

Tacumshin Lake 0

0 Site: Tacumshin Lake Transect code: F Location: Freshwater inflow Sample point: 3 Marg inal Sample area: 100m2 10x10 Substrate: Silt 0

Depth: 20 cm Salinit : 4arts per thousand NVC communit :S21 Scir us maritimus swam - A rostis stolonifera sub-community Height cm Cover 0 Total Plant 100 0 Scius maritimus 140 75 Schoeno lectus lacustris sstabernaemontani 160 < 1 A rostis stolonifera 30 30 0

Description: Scius maritimus swam with p atchy round cover of Arostis stolonifera. 30m 0

0

0 Site: Tacumshin Lake Transect code: F Location: Freshwater inflow Sam leoint: 4 Marginal Sample area: 100m2 10x10 Substrate:Silt 0 Depth: 0 - 20 cm Salinit : 2arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover 0 Total Plant 100

Phra mites australis 260 100 0

0 Description-. Dense single species Phra mites swamp. 30m. Backing A rostis stolonifera dominated community with frequent Ranunculus acris and Mentha a uatica. 5m. 0 Grading to Lolium erenne - Dact lislomerata pasture.

0

0

0

0

a

25 0 Tacumshin Lake

2.3.4Evaluation

'Valuable' M J This large site was surveyed bytransects only. Therefore, the information available upon which to make this assessment is limited compared withmost other sites. Five transects were carried out at the lagoon itself andone at a channel at the western end of the site.

This is one of six Irish sites at which Chara 7U canescens has been recorded since 1970. This rare charophyte was foundon this occasion growing sparsely in a northern bay. It was also found in a western channel during a previoussite visit.Its presence alone is reason enough to regard Tacumshin Lake asa valuable site. J Ruppia c.f. maritimawas found at four out of five lagoon transects. Itgrows in occasional dense beds within 50 metres of thebarrier shore. J Potamogeton pectinatuswas found at the two northern transects and ina western channel, forming moreor less dense beds at all of these.

A previous site visit found Potamogeton pusillus,Zannichellia palustris, Myriophyllum spicatum and Ranunculus baudotiiat low salinities (0-4 parts per thousand) in western and northwestern channels amongst swamp vegetation.

Salinity range was great at time ofsurvey (13-35 parts per thousand in the main body of the lagoon and 4 -3 5 partsper thousand taking the surveyed western channel into account). This variation is reflected in the relativelyhigh degree of species diversity found at the site.

The most notable feature of the marginalvegetation is the extent of swamp species. Phragmites and Schoenoplectus beds fillthe two north western bays and much of the south western area. These species and Scirpusmaritimus fringe much of the north shore and are again extensive in the northcentral and the north eastern bayheads. J Tacumshin Lake is considered valuable for itsspecies diversity and spatial salinity variation, for its extensiveswamps and for the presence of Chara canescens.

Further survey is recommended.

U

J

26 M u Tacumshin Lake

2.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

2.4.1Site Description

Large coastal brackish lake with sand barrier with inflow percolationsprings, overtopping, and a recently rebuilt artificial pipe, as sources of seawater. South-westerndune breach has been closed for some years. Lake shore with medium-textured sandnear coastal dune barrier, with sandflats which were exposed during latesummer opening of pipe blockages (Plates 1 and 2). Marginal vegetation near barrier includes Scirpus maritimus and Agrostis stolonifera;also J halophytic vegetation near percolation springs. Phragmites communes beds andother marsh vegetation with deep organic layer on interior inlet shores.

Subsites (see Fig. 2.4. 1)

1. Agrostis stoloni era (T 033054) Agrostis stolonifera with Potentilla anserina grading into Scirpus maritimuson sand. Sampled during rapid groundwater drawdown.

2. Percolation spring (T 056054) Shallow banks of percolation spring with halophytic vegetation. Saline springinflowing during high spring tide after heavy rain event (22 August 1996,salinity 9%0).

3. Bare sand near old breach (T 028053) Bare sand (created by plough furrows) behind dunes of oldbreach area, flooded by water in winter.

2.4.2 Methods Site Rating using Indicator Species Species rarity or community typicalityare the most frequently used criteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating thepresence of rare beetles. 1 Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if:(1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon J 27 J a

0

0

i 0

0

0

0

Fig. 2.4.1 Map of sampling sites (Carabidae and Staphylinidae) atTacumshin Lake, Co. Wexford 0 1 - Pitfall traps 2 - Pitfall traps, S-vac 3 - Ground search, Flotation 0

0

0

G J

J Tacumshin Lake

margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.)or herbivorous J assemblages (e.g. Lepidoptera). Different indicator species are likely tooccur in spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses,as well as bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 2.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100x 1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species

M 28 U Tacumshin Lake 0 expected to occur in such a habitat are adapted toclimbing during flooding, these traps were 0 fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 0

TABLE 2.4.1. Details of sampling methods. 0

0 Method Details No, replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels; collars used where cattle/horses occur 0 Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth 0 burrow casts observed; agitated soil floated in water 0 Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer 0 substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 0 subsamples of 5 x 5 x 10 cm) extracted by flotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn (late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated 0 with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent. 0 Variety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare 0 sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is 0 not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site. 0

29 Tacumshin Lake

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for J invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 14:48-53,

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : Agrostis stolonifera area- S-vac suction sampler (13 ix 1996), c. 2m2; Agrostis stolonifera area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (13 ix- 8 x 1996); Percolation spring- 6 pitfall traps (23 viii - 13 x 1996); Bare sand near old breach- 1 h ground search with flotation of Bledius burrows(18 vii 1996).

30

L Tacumshin Lake

Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems.

2.4.3Survey Results

TABLE 2.4.2Carabidae and Staphylinidae (Coleoptera) recorded from Tacumshin Lake. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0

Species No. individuals Carabidae 0

Acupalpus parvulus (Sturm) 1 Agonum marginatum (L.)8 0 Agonum pelidnum (Payk.) 14 Bembidion assimile Gyll.4 Bembidion guttula (F.) 1 0 Bembidion varium (01.) 29 Dyschiriusglobosus (Hbst.) 4 Dyschirius luedersi Wagn. 11 Elaphrus cupreus Duft. 1 0 Pterostichus melanarius (Ill.) 1 Pterostichus niger (Schall.) 1 0 Staphylinidae

Aleochara bipustulata (L.) 3 Aloconota gregaria (Er.) 1 0 Atheta amplicollis (Muls. Rey) 18 Atheta fungi (Grav.) 3 Atheta graminicola (Grav.) 43 0 Atheta melanocera (Thoms.) 4 Atheta volans (Scriba) 11 Blediusgallicus (Grav.) 6 0 Gabrius pennatus Sharp 1 Gabrius subnigritulus (Reitt.) 1 Gnypeta carbonaria (Mannh.) 3 Ischnopoda atra (Grav.) 2 0 Ocypus olens (Mull.) 6 Paederus fuscipes Curt. 18 Philonthus carbonarius (Grav.) 1 0 Philonthus micans (Grav.) 3 Philonthus quisquiliarius (Gyll.) 2 Philonthus varians (Payk.) 1 0 Stenus boops Ljungh 16 Stenus canaliculatus Gyll. 3 Stenus clavicornis (Stop.) 1 Stenus juno (Payk.) 10 0 Stenus melanopus (Marsh.) 4 Stenus nigritulus Gyll. 1 Indicator species Tachyporus chrysomelinus (L.) 29 0 Tachyporus hypnorum (F.) 5 Tachyporus pusillus Grav. 2 0

31 J

Tacumshin Lake n J Eleven species of carabid and twenty-seven species of staphylinid wererecorded, one species of which is regarded as an indicator species (Table 2.4.2).

A single individual of Stenus nitidulus was recorded from baresand near the previous south- western breach area. The species is only known in Irelandfrom one record (1910) from Lough J Neagh (Anderson 1984), although it was also found at LoughMurree (Co. Clare) during this survey. It is very local and declining in Britain (Hyman& Parsons 1994), and scattered and rare in (Horion 1963). However, it is not rarein Fennoscandia, and is common in eastern Central Europe (Horion 1963). The species is restricted tomarshy shores, including flooded meadows (Horion 1963), riverbanks and salt-marshes (Hyman & Parsons1994), but also on sea shores (Koch 1989).

2.4.4Evaluation

Coastal barrier area of low conservation interest for terrestrial ecotonalcommunity. (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating

The presence of only one individual of one indicator speciesindicates low conservation interest for the coastal barrier area. However, this is a largesite, and priority was given to the coastal barrier. The interior redbeds and marshes may have a highervalue. The large amount of disturbance due to dewatering (Plate 1) may render the coastalbarrier part an unsuitable habitat, and the indicator species (Stenus nigritulus) may have itscore population in the more marshy interior parts of the site. 7 2.4.5References

Anderson, R. (1984) Staphylinidae (Coleoptera) in Ireland- 3: Steninae. Ir. Nat. J. 21. 242- 251. Horion, A. (1963) Faunistik der Mitteleuropaischen Kafer. IX. Staphylinidae: Micropeplinae bis Euaesthetinae. Feyel, Oberlingen-Bodensee. Hyman, P. S. and Parsons, M.S. (1994) A review ofthe scarce and theatened Coleoptera of Great Britain. Part 2. UK Nature Conservation Series No. 12,Joint Committee for Nature Conservation, Peterborough. Koch, K. (1989) Die Kafer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die Kafer Mitteleuropas. 12.1. Supplementband mit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die Kafer Mitteleuropas. Katalog. Goecke & Evers,Krefeld.

32 Tacumshin Lake

2.5 SUMMARY AND EVALUATION

Tacumshin Lake is a large (c. 450 ha), natural sedimentarylagoon and is therefore of international importance based on the Habitats Directive. The lake is of outstanding ornithological interest, of international importancefor Brent geese and nationally important for 11 waterfowl species. Itis a proposed SPA and a proposed NHA (Site Code 709). The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology Exceptional Aquatic Fauna High Vegetation High Ecotonal Coleoptera Low J

Geomorphology Tacumshin is one of the largest and best examples ofa true lagoon in the whole of Europe. It is a large natural sedimentary lagoon with extensivedocumentation of the barrier morphology and processes. The lagoon has suffered from drainageattempts, water levels in the lagoon have been lowered by theinstallation of pipes through the barrier and excavation of drainage channels in the bed ofthe lake, but the lagoon and barrier itself are still of exceptional conservation value and meritbetter protection. The site is rated as of exceptional conservation value forits size and special interest of the barrier which is well documented. Aquatic Fauna The aquatic fauna was rich with 40 taxa recorded ofwhich 6 are lagoonal specialists. Insects were abundant and Corixidae and Coleoptera were particularly diverseand include one rare backswimmer (Notonecta viridis). The assemblage typifies alow salinity lagoon with a consistently high input of freshwater, andfew opportunities for colonisation from the sea. Plea leachi and Gerris thoracicus were not recorded at anyother site during this survey although both are regarded as slightly brackish species. Sigaraconcinna was described as rare in Ireland but was found also atLady's Island L. and Kilkeran L. during this survey. Pungitius pungitius is listed in the IrishRed Data Book as a "near threatened" species needing to be closely monitored. Despite the fact that water levels are generally very lowduring the summer months, a surprisingly high number of species, including lagoonal specialists were recorded.

33 J

Tacumshin Lake

The lake is rated as of high conservation value for aquatic fauna on the basis of high diversity and the presence of somewhat rare species.

Vegetation

This large site was surveyed by transects only. Therefore, theinformation available upon which to make this assessment is limited compared with most other sites.

This is one of six Irish sites at which Characanescens has been recorded since 1970. Its presence alone is reason enough to regard Tacumshin Lakeas a valuable site. Ruppia c.f maritima was found at four out of fivelagoon transects. Potamogeton pectinatus was found at the two northern transects and ina western channel, forming more or less dense beds at all of these. A previous site visit found Potamogeton J pusillus, Zannichellia palustris, Myriophyllum spicatum and Ranunculus baudotii at low salinities (0-4 parts per thousand) in north western channelsamongst swamp vegetation.

Salinity range was great at time of survey (13-35 %oin the main body of the lagoon and 4 -35 %o taking the surveyed western channel intoaccount). This variation is reflected in the relatively high degree of species diversity foundat the site.

The most notable feature of the marginal vegetation is theextent of swamp species. Phragmites and Schoenoplectus beds fill the two north western baysand much of the south western area. These species and Scirpus maritimus fringe muchof the north shore and are again extensive in the north central andthe north eastern bayheads.

Tacumshin Lake is considered valuable for its species diversity andspatial salinity variation, for its extensive swamps and for the presence ofChara canescens.

Further survey is recommended.

Ecotonal Coleoptera

J Eleven species of carabid and twenty-seven species of staphylinid wererecorded, one species of which is regarded as an indicator species.

A single individual of Stenus nitidulus was recorded from baresand near the previous south- western breach area. The species is only known in Irelandfrom one record (1910) from Lough Neagh, although it was also found at Lough Murree (Co.Clare) during this survey. It is very local and declining in Britain, and scattered and rare inFrance. However, it is not rare in Fennoscandia, and is common in eastern Central Europe. The speciesis restricted to marshy shores, including flooded meadows, riverbanks and salt-marshes, but also onsea shores.

The presence of only one individual of one indicator speciesindicates low conservation interest for the coastal barrier area. However, this is alarge site, and priority was given to the coastal barrier. The interior reedbeds and marshes mayhave a higher value. The large amount of disturbance due to drainage may render the coastal barrier part an

34 u

Tacumshin Lake 0 unsuitable habitat, and the indicator species (Stenus nigritulus) may haveits core 0 population in the more marshy interior parts of the site.

For the above reasons, the coastal barrier area is consideredof low conservation interest for 0 terrestrial ecotonal community.

Summary 0

Tacumshin Lake is a very large natural sedimentary lagoon. Despitedrainage attempts, itis still largely natural, although current management practices are 0 controversial and effective solutions to the conflicting interests are subjectto financial constraints. 0 The lagoon and barrier are good examples of geomorphological typesand there is a the lagoon long history of scientific investigations. Together with Lady's Island Lake, 0 is one of the two best documented in Ireland. Ofparticular interest are local geomorphological processes. 0 Several rare species were recorded during this brief survey, andmany are "interesting" lagoonal specialists. 0 The lake is of great local importance and is ofhigh scenic value

In conclusion, based on geomorphology, fauna and vegetation, Tacumshin Lake a is regarded as of exceptional conservation value and highly recommendedas a proposed SAC. 0

0

0

0

0

0

a

0

0

35 E7 Tacumshin Lake

44

mi

r] Plate 1 Exposed sandflats at Tacumshin Lake, Co. Wexford

0

0

0 r

0

0 Plate 2 Recently opened pipe outlet at Tacumshin Lake, Co. Wexford r COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111) J

3. KILKERAN LAKE

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

S

Prepared for the National Parks and Wildlife Service

(BioMar/Life) J 3. KILKERAN LAKE

CONTENTS

3.1 Study Area 7 LJ 3.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

3.2.1Methods 3.2.2Results 3.2.3Discussion 3.2.4Threats 3.2.5Evaluation 3.2.6References

3.3 Vegetation Survey (Pat Hatch)

3.3.1Site Description 3.3.2Methods 3.3.3Results Shore based survey J Transect tables 3.3.4Evaluation

3.4 Ecotonal Coleoptera (Jervis Good)

3.4.1Site description 3.4.2Methods 3.4.3Results 3.4.4Evaluation 7 3.4.5 References Li 3.5 Summary and Evaluation J r1 J

1 J

Kilkeran Lake

7 3. KILKERAN LAKE, Co. Cork. J OS Grid Reference: W 338 344, 1:50,000 Sheet No. 89 Alternative names: Kilkern Lake, Kilkieran Lake, Kilkerran Lake

3.1 STUDY AREA

General features Kilkeran Lake is a natural lagoon, lying behind sand hillson the south coast of Co. Cork, about 5 km east of the town of Roscarberryand 2 km north of Galley Head (Fig. 3.1.1). A channel leads from the lagoon 400 mto the shoreline where the water of the lake is impounded for most of the yearby a short, coarse sand barrier. It appears that the County Council periodically breach the shingle barrier (8/10/92)but that it also opens naturally, mainly in the winter when water levelsrise. The barrier closes again naturally, generally within a few weeks. According to localinformation the area between the lake and the coast was previously a marsh,and when a road was built along the coast, a channel was dug from the lake.A bridge carrying the road now crosses this channel. The lake is included in a proposedNHA. (Site Code 01061) which includes the lake itself together with Castlefreke dunes, partlyowned by the NPWS. The site is of high scenic value with thelake lying in a hollow between the dunes and wooded hills. The woods themselvesare plantation conifers but the dunes are natural and relatively unchanged. i The lake has suffered from eutrophication, and theonce thriving trout fishery has now gone. A water quality and phytoplankton survey was carried outon behalf of the NPWS in 1993-94. J Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 7°C in January and15.5°C in July. The growing season (the period of mean daily air temperatures above 6°C) is 11 months and as i snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1000 mm, and the number of raindays (1 mm or more) is 150- 175. Prevailing winds are from the south and southwest. Meanannual hourly wind speeds are 5.5 m/s and a maximum wind speed of49-50 m/s is estimated to occur once in 50 years. The daily duration of bright sunshineaverages 3.5-4.0 hours. Mean i relative humidity is around 85% as on all Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with r-1 median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce I j large waves, (Carter 1992). Maximum wave heights (averagingonce in 50 years) are 20-25 m (Couper 1984). Tides are semi-diurnal and the tidalrange (MHWS-MLWS) in Clonakilty Bay is 3.5 m (Admiralty Tide Tables).

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Di nowen Head I 0 homonl Casuc j le Com

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0 Fig. 3.1.1Section of 150 000 map showing locality of Kilkeran Lake

0

0 Kilkeran Lake

Landscape and Geology Bedrock is and soils are brown podsols and dry mineral soils, producing relatively good agricultural land. Land surroundingthe lake comprises dunes, coniferous woodland and pastureland. 7 lJ Lake Topography The lake is approximately 600m from north to south, 400m across, and covers about 16 ha. The lake is shallow(<3 m) and most of the bed of the lake is sand with a deep layer of organic mudin the deeper areas, and stony patches along parts of the shoreline.

Hydrology A channel leads from the lagoon 400m to the shorelinewhere the water of the lake is impounded by a short coarse sandand gravel barrier. It appears that the County Council periodically breach the shingle barrier (8/10/92) but thatit also opens naturally, mainly in the winter when water levels rise. Thebarrier closes again naturally, generally within a few weeks. A limited amount ofseawater enters while the outlet is open and also by overtopping the barrier whenit is closed. There are no tidal fluctuations in water level, but the seasonal variationmay be up to a metre. The outlet channel appears to be eroding its eastern banknear the barrier which poses a threat to houses close to the shore.

Salinity and water quality A limited amount of seawater enters while the outlet is open and also by overtopping the barrier when it isclosed, but the volume of J freshwater flowing from the lakeensures a low salinity for most of the year. Galvin measured 6 %o in 1991 and during a water qualitysurvey, carried out on behalf of the OPW. from June 1993 to May 1994, an annualrange of 0.2 - 4.4 %o was recorded. There have been considerable problems with eutrophication of the lakecaused by a nearby piggery, milk unit and runoff from surrounding fields. Thesituation seems to J have improved somewhat, although SW Regional Fishery considered restockingof the lake with trout a waste of time andmoney.

rl J 2 1 J Kilkeran Lake

3.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver, Dept. of Zoology, University College Dublin

J 3.2.1. Methods Environmental variables A transverse profile of the barrier was drawn using heightsmeasured with a builders level and staff Water depths were measured usinga plumbline from an inflatable dinghy.

The position of each sample area was determined usinga GPS Personal Navigator UI (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. maps andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o precision). A photographic recordwas made of the site and local information sought concerning background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-trapswere left overnight at certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxes were constructed in the ZoologyDept. at U.C.D. according to the model described by Holmes & O'Connor (1988). Faunalsamples were preserved in 70% alcohol and stored for subsequent sorting and identification. J Fyke nets were used at stations A, B, D andE in order to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16mm. The trap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right anglesto freshwater inflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the surveyare affected by many environmental and biotic variables including season, state of the tide, weather,nature of the habitat and life J cycles of the species involved. It is therefore difficultto make quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often with a different samplingmethod. The results of

3 U Kilkeran Lake a the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution 0 within the water column. Abundance categories of present,common and abundant are purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were 0 used to identify remaining specimens, but many of these werelarval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for identification and these were often not available due to lowpopulation density and the 0 limited number of individuals collected in the time available (e.g.hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify when preserved (turbellarians, leeches). D All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same 0 species.

3.2.2Results 0

Kilkeran Lake was sampled on 4.vii.96 during the firstpart of the survey, and from 25- 0 27.vii.96 during the more intensive survey.

Sampling stations were selected in the lake to reflect theinfluences of substrate, 0 freshwater and tidal inflows. Positions of the sampling stationsare shown in Fig. 3.2. 1. Further details are given in the Results section. a

Environmental Variables 0 Figure 3.2.2 shows a profile of the barrier. 0 Station A (OS 3360 3426) was locatedon the southwest shore of the lake, close to the access road and an area where small boatsare launched. Substrate varied from gravel and sand to soft organic mud with occasional stones.Water depth was 0-1 m a and salinity measured1 %o (Plate 3.2.2). Station B (OS 3389 3404) was located in the southernpart of the lake where the outlet channel leaves the lake. Water depthwas 0 - 2m, substrate varied from sand to 0 soft organic mud and salinity measured 2%0 (Plate 3.2.2). Station C (OS 3379 3454) was located in the northwestpart of the lake close to 0 where a freshwater stream enters the lake. Substrate consisted largelyof stones of various sizes with patches of sand or silty mud. Waterdepth varied from 15- 100 cm and salinity measured 2%0 (Plate 3.2. 1). IJ Station D (OS 3407 3425) was located on the easternshore of the lake. Substrate was shaly stone along the shore with soft organic mud indeeper areas. Water depth was 15 - 100 cms and salinity measured 1-2%0 (Plate 3.2.1). D

0

a 4

a J

35

J

34

J

I I I 1-\k I I I I I J Position of outlet 34 3/12/96

Fig. 3.2.1 Location Map of Sampling Stations in Kilkeran Lake, Co. Cork rl LJ ri LJ 10 M. water level Cobble barrier of lagoon recent H.W.M. 0 beach (1800eel hrs, of sea11/8/96) O M. 50 m 100 m CC! C7 C C] C7 C C CC C] C7 Fig. 3.2.2 Profile of Barrier at Kilkeran Lake, Co. Cork. C] CT] C J CJ C J C7 C] C J C] C3 C' Table 3.2.1 Fauna Recorded at Kilkeran Lake, Co. Cork. June July 1996. ( ) = records from July

---- I Sampling Stations ( L.T. = light-trap) -A L.T.AI B T . B ., C L.T.Ci D iL.TD E - Porifera ! ------'--G Cnidaria I Turbellaria - -- I - - i I - J Nemertea I j - i -- j Annelida - - --'-- 1 - _ __ Crustacea - j_ --- t - - - - -i --- Ostracoda ---- i Copepoda - -- -- Cirripedia Mysidacea Neomysis integer c c l00 a >100 a c750 o 33 + Isopoda AmphipodaAllomelita pellucida +

J Gammarus duebeni + , + + Orchestia gammarella + Tanaidacea DecapodaPalaemonetes varians c 5 a 59 o 4 c + Arachnids

Insecta i Thysanura

EphemeropteraCloeon dipterum + + i Odonata Ischnura elegans (+) J Plecoptera +

Trichoptera I J Diptera Chironomidae a 3 c c c 1 c Hemiptera Corixidae a 1500 a 1000 c 250 c 150 c

Corixa panzeri + 1 + + + Sigara concinna + a + + + + + + +

S. dorsalis j 3 I I + + l +

S. stagnalis 1 _ Notonecta glaucum +

N. viridis +

*Hydrometra gracilenta j H. stagnorum + j_ - Coleopteral( incl. larvae) -----_ a- a -- + + ------

Arwaena lutescetu i + I I ------_ _

- ' + j i ercyon marinas - r-+ T Y ICoccidula ntfa

1Gyrinus caspius ------+ ------

I Helophorus brevipalpis j +

'**Hydroporus angustalus ------+------1------I------H. palustris J

+ = present; o = occasional; c= common; a =abundant; * = recorded by Galvin, 1992 - see text; **= Sample Station not known.

1 u Table 3.2.1cont..Fauna Recorded at Kilkeran Lake, Co. Cork. June July 1996. ( ) = records from July IJ Sampling Stations ( L.T. = light-trap)

A L.T.A B L.T.B. C L.T.CI D L.T.D E IJ

Mollusca Prosobranchia Potainor us antidamn + + c + ? 0 Pulmonata _ Opisthobranchia Bivalvia IJ Bryozoa Plumatella repens + +

? Fredericella sultana + j i

Echinodermata I tJ Tunicata Teleostei Anguilla anguilla + + + + Gasterostetu aculeatus + 2 a 2 a 1 + + IJ Pomatoschistus microps + 2 Platichth s esus + + + 1 EJ

IJ

EJ

0

EJ

tJ

0

D

D

0

0

+ = present; o = occasional;'a = abundant; F =fyke net EJ

0

0 Kilkeran Lake

Station E (OS 3374 3356) was located in the pondedarea inside the barrier. Substrate consisted of sand and gravel, water depth was 0- 1 m and salinity measured 2%0 despite the close proximity of the sea (Plate 3.2.3).

Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 3.2.1. Among 30 taxa listed, 29 are identified tospecies. The bryozoans await confirmation. Eight of the species are euryhaline, 6 are oligo-mesohaline,and 15 are limnic; no marine or poly-mesohaline species were recorded (Table 3.2.2).Three species are listed as lagoonal specialists in Britain (Davidson etal. 1991). Neomysis integer and Corixidae were extremely abundantat all stations in the main body of the lake and large numbers were taken inlight traps. The fauna was similar throughout the lake, reflecting the absence of salinity variation. Nospecies was confined to E, which suggests that barrier overwash and thepresence of an occasional seawater incursion does not introduce marine colonists. The low salinityat this station also indicates that effects on the fauna of seawater incursionswould be small. The benthic fauna throughout the lake was particularlypoor and only larvae of chironomidae were found in soft sediments.

Table 3.2.2 Ecological categories of the recorded taxa in Kilkeran Lake (L= lagoonal specialist according to (Davidson et al. 1991). UI Marine None

Poly-mesohaline None

Euryhaline Neomysis integer Gammarus duebeni Palaemonetes varians L Sigara stagnalis L Gasterosteus aculeatus Anguilla anguilla Pomatoschistus microps Platichthysflesus

Oligo-mesohaline Potamopyrgus antipodarum Ischnura elegans Sigara concinna L J Notonecta viridis Gyrinus caspius Allomelita pellucida*

Limnic Cloeon dipterum Hydrometra gracilenta H. stagnorum Notonecta glauca n Corixa panzeri Sigara dorsalis J Plecoptera A nacaena lutescens Cercyon marinus Coccidula rufa Hydroporus angustatus

J 5 u Kilkeran Lake

tJ N. palustris Helophorus brevipalpis Plumatella repens Fredericella sultana (.2) tJ

* The full range of this species is not known 0 3.2.3Discussion 0 The faunal assemblage is typical of a lagoon without asea inlet where a low salinity persists and marine influence is small. Although occasional breaching ofthe barrier may introduce species more characteristic of higher salinity, these probablydo not tJ survive for long after the sea inlet reseals. Hydrometra gracilenta was identified from specimens collected by Galvin (1992).This a is a first record for Ireland and was not foundat any other site. According to Southwood and Leston (1959) Notonecta viridis was onlyreported for Wexford and north Kerry. It has since been recorded atLady's Island L. by Healy et 0 al. (1982) and at Lady's Island L. and the NorthSlob by Galvin (1992). It was found at Lady's Island L., Tacumshin L., and L. Donnell andthe North Slob during this survey. Sigara concinna was described as rare in Ireland (Southwoodand Leston 0 1959) but was found also at Lady's Island L. andTacumshin L. during this survey and in Kilkeran L. was extremely abundant and the dominant species.Both Neomysis 0 integer and corixids were more abundant in this lake thanat any other site sampled during the survey. This is the only site at which the beetles Anacaenalutescens, Cercyon marinus and 0 Coccidula rufa were recorded but details of their distribution inIreland are not known at present.. 0 Galvin (1992) recorded 44 species of aquatic fauna in 1991,including the rare lagoonal bryozoan Victorellapavida which may have been misidentified. Other interesting species include the two freshwater bryozoans, one of which maybe new to Ireland. 0

3.2.4Threats Ei High nutrient levels from agricultural sources may be having anadverse effect on fauna. 0 There is some recreational use of the lake but thisdoes not appear to be a threat. The outlet channel appears to be eroding its eastern banknear the barrier which poses 0 a threat to houses close to the shore. 3.2.5Evaluation 0

Kilkeran Lake is a natural sedimentary lagoon and is thereforeof international importance based on geomorphology alone. tJ

0

6 0

0 Kilkeran Lake

The site lies within an area of relatively unspoilt sanddunes and, although small, is probably the best example in the southwest of Ireland ofa lagoon with a sand/gravel barrier.

Barrier morphology is well documented and studies of its historyare ongoing. For such a small lake, the aquatic faunaappears to be diverse. One skater is a new Irish record, a backswimmer is rare in Ireland, anda bryozoan may be new for Ireland. The lake lies within a proposed NHA (Site Code No.1061). The lake is high conservation value for its interesting geomorphology,and aquatic faunal analyses to date indicate that this fauna comprisessome rare species which also deserve protection. Its designationas a proposed SAC is recommended.

3.2.6References and Additional Sources

Admiralty. 1995. Admiralty Tide Tables: Europeanwaters including the J Mediterranean Sea. Taunton, UK: Admiralty HydrographicDepartment Barnes, R.S.K. 1989 Coastal lagoons of Britain:an overview and conservation appraisal. Biological Conservation 49, 295-313. J Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of theEnvironment, 125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N. C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBSReport 1994-1995. 1WC Birdwatch Ireland.109pp. Galvin, P. 1992 The ecology of the brackish-water lagoonsof Wexford and East Cork. M.Sc thesis, University College, Dublin. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the Marine Biological Association of the United Kingdom 68: 235-238. J Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy.144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke netas a sampling instrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the Europeaneel (Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special referenceto growth and movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The StationeryOffice. 146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Preparedunder the direction of the Irish National Committee for Geography. Royal IrishAcademy, Dublin. 104pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish WildbirdConservancy, 152 pp. Southwood, T.R.E and Leston, D. 1959. Land andwater bugs of the British Isles. Wayside and Woodland series. Warne and Co., London.446 pp.

7

1 a r r

0 r

Plate 3.21View of Kilkeran Lake looking north, Station C (on theleft) and D (on the right) a

IN 0

99

a Plate 312 View of Kilkeran Lake looking east, Station A(foreground) and B (distance)

mm r

In

0 r

Plate 3.2.3 View of the outlet channel looking south toward the barrierof Kilkeran Lake, Station E.

go

IN ran r

Plate 3.2.4 View of the barrier of Kilkeran Lake lookingeast from the sand dunes. as Kilkeran Lake

3.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

3.3.1Site Description (Fig. 3 3 1)

Kilkeran Lake is set amongst low hills with predominantly pastoral farmland to the north, east, south east and west. A conifer plantation liesclose to the mid-western shore and another, now partly derelict, to the south west.The dune barrier lies to the south west, through which the outlet to the sea runsfrom the southern point of the lake.

A public road passes between the lake and the dunesand a track runs along the western shore.

The major freshwater inflows (two) join the lake at itsnorthern point, where an extensive Phragmites bed fringes the lake and extends back upthe inflow valley.

A more or less narrow band of swamp vegetation fringesthe lake along all but the north eastern shores, which are more open. Exposed bedrock formsthe shore on a promontory in this area. Elsewhere the shore is gently sloping.

3.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 3.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage

8 0

a

Paus 0

B 0 PLUS

_ Pau515v4ar 0

IPS 0 Sldc 0 Smor

5Mdr/5(dc 0

paus 0

S.nar 5ldc 0

0

Kry= bec{rock -Exposed 0

S vvct -C/ re n 0 species ccde s : da54rdli5 du5 - Phr49m 1 e$ 0 srvdr - Scirpusmori+irnu5 skit _ lec+us (dcu5ff i5 ssp 0 IP5e-lr'i5 p5ucJacoru5 I-i t1Wcrf-er , Mark 0

0

0

0 Fig. 3.3.1 I iKerdn l,a

0 T

r1 U N

J

/I cluafic /mc-Itldl V2gefdfion T

Fig. 3.3.2 Kilkeran Lake, Co.Cork: Location of Transects and Shore-based Survey Sections

1 u

Kilkeran Lake 0 cover of each species were estimated and recorded togetherwith the total plant, higher 0 plant and algal cover.

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was felt thatthis location method was more accurate 0 and made sample areas more re-locatable than one related to,for instance, high water mark, as this is difficult to establish at many sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was a generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 0 9 76-90 % 8 51-75 % 7 34-50 % 0 6 26-33 % 5 11-25 % 4 4-10 % 0 3 <4 % -many individuals 2 <4 % -several individuals 0

9 J

Kilkeran Lake

1 <4 % -few individuals

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100% IV 61-80 % III 41-60 % II 21-40 % I I-20 %

9 Note: The NVC volume covering saltmarsh communities was not availableat the time lJ of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume. J Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located at the outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal J communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel) except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

J

10 u

Kilkeran Lake 0

Constraints 0 Time. Restrictions on the time available in which to carryout this survey had the following consequences: 0 a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey, b). Marginal NVC survey was carried out on representative standsonly 0 (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why this 0 is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was 0 working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores. 0 Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & 0 Wildlife Service 0 Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous 0 green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0 Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0 Nomenclature

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin 0 & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0

Evaluation 0 This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey. 0 The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not 0 a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen 0 algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

II 0 J

Kilkeran Lake

A `Valuable' site is one that is shown to beof particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable' site is one that is shown tobe of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

3.3.3Results

1. Shore-based survey

Section A-B (Transect A)

Aquatic: Ruppia maritima J Potamogeton pectinatus Chara aspera var. aspera

Sand and silt substrate

Marginal:Dense single species Phragmites swamp. 25-35m

Adjacent:Grading to dune grassland with Elymus farsctus, Potentilla anserina, Trifoliumrepens, Lotus corniculatus, Plantago lanceolata, Galium verum. ------Section B-C

Aquatic: Potamogeton pectinatus Marginal:Unchanged

Adjacent:Agrostis stolonifera - Potentilla anserina dominated grassland. 10-20m Arrenatherum elatius and Pteridium aquilinum dominant with sparse and partly derelict conifer plantation on dune grassland ------Section C-D

Aquatic: Potamogeton pectinatus - dense bed to c.5m out Enteromorpha

Marginal:Single species Scirpus maritimus swamp. 2-3m

Adjacent: Agrostis stolonifera - Potentilla anserina dominated grassland. 5-20m Backing to public road and conifer plantation J

12 u

Kilkeran Lake 0

Section D-E (Transect B) 0

Aquatic: Potamogeton pectinatus - dense bed to c.5-10m out Polygonum amphibium - occasional 0 Enteromorpha - sparse

Marginal: Swamp vegetation. Single species Phragmites stands alternating with 0 Scirpus maritimus dominated stands with sparse Schoenoplectus lacustris ssp tabernaemontani. 3-6m 0 Grading to narrow strip of freshwater species.1-3m. Iris psuedacorus, Filipendula ulmaria, Lythrum salicaria, Stachys palustris typically frequent with Agrostis stolonifera and Potentilla anserina locally 0 dominant 0 Adjacent:Public road Conifer plantation ------0 Section E-F

Aquatic: Potamogeton pectinatus - dense bed to c. 15m out 0 Enteromorpha

Marginal: Schoenoplectus dominated swamp with frequent Scirpus maritimus. 2-4m D Grading as D-E

Adjacent:Public track 0 Lolium perenne pasture

------Section F-G 0

Aquatic: Potamogeton pectinatus - as E-F Polygonum amphibium - occasional 0 Enteromorpha

Marginal:Phragmites and Schoenoplectus swamps as D-E. 4-10m 0 Grading as D-E 0 Adjacent:Unchanged

------Section G-H (Transect C) 0

Aquatic: Potamogeton pectinatus - no longer in dense beds 0 Marginal: Single species Phragmites australis swamp extending back along freshwater inflows 0 Adjacent:Pasture and meadows

------0

13 0 Kilkeran Lake

Section H-M - Access refused by landowner. Surveyed from westernshore and from Section M-N. Accounts of the following five sections are therefore J incomplete

Section H-I

Aquatic: Unknown 7 1J Marginal:Bedrock shore. No emergents

Adjacent:Narrow strip of Rubus fruticosus and Ulex sp. on steepbank J Backing to pasture ------Section I-J

Aquatic: Unknown

Marginal:. Iris psuedacorus locally dominant. Narrow shore backing to steep slope

Adjacent:Pasture ------Section J-K

Aquatic: Potamogeton pectinatus - dense bed to c.10-20m out

Marginal:As H-I

Adjacent:As H-I

Section K-L

J Aquatic: Potamogeton pectinatus - dense bed to c.20-30m out Polygonum amphibium - occasional

Marginal:Sparse Iris psuedacorus with Eleocharis sp., Agrostis stolonifera. 3-5m strip

Adjacent:Unchange ------Section L-M U Aquatic: Unchanged 7 LJ Marginal:Mixed Schoenoplectus - Scirpus maritimus swamp. c.3m Grading to Phragmites stand associated with small freshwater inflow

Adjacent:Pasture

14 u

Kilkeran Lake 0

0 Section M-N

Aquatic: Potamogeton pectinatus - dense bed to c.15-20m out E

Marginal: Schoenoplectus, Scirpus maritimus and Eleocharis palustris swamps,each species locally dominant. 1-3m C Grading to Iris psuedacorus dominated strip with frequentEpilobium hirsutum, Filipendula ulmaria, Lythrum salicaria, Stachys palustris,Urtica dioica. 2- D 4m 0 Adjacent:c.45 degree bank to c.5m height with Rubus fruticosus,Ulex europaeus and Pteridium aquilinum dominant 0 Backing to Lolium perenne pasture ------Section N-O a

Aquatic: Potamogeton pectinatus - dense bed to c. I Om out 0 Marginal:Swamp as M-N Grading to Phragmites dominated fen vegetation on smallfreshwater inflow 0 stream. Frequent Iris psuedacorus, Epilobiumhirsutum, Filipendula ulmaria, Lythrum salicaria, Angelica sylvestris, Urtica dioica.c. 60m 0

Adjacent:Lolium pasture and arable land

------0 Section O-P

Aquatic: Unchanged 0

Marginal:As M-N 0 Adjacent: Steep bank as M-N with frequent Alnus glutinosa andSambucus nigra Backing to pasture and arable land 0 ------Section P-Q a Aquatic: Potamogeton pectinatus -dense bed narrowing to c.3m out

Marginal:Dense single species Phragmites swamp. 20-25m e Grading to Phragmites dominated stand with frequentUrtica dioica. 2-5m

Adjacent:As M-N 0

0

15 0 Kilkeran Lake

2. Transects

Site: Kilkeran Lake Transect code: A Location: Outlet to sea Sample point:1 Aquatic - 1 m out -grapnel Sample area: Grapnel only Substrate: Sand, silt Depth: 80 cm + Salinit: 2arts per thousand NVC communit :----- Height cm Cover

Potamo eton ectinatus Ruis maritima Chara as era var. as era

Description: Some Ruis plants in fiuit.

Site: Kilkeran Lake Transect code: A Location: Outlet to sea Sample point: 2 Marginal Sample area: 100m2 10x10 Substrate: Silt Depth: 0 - 60 cm Salinit : 2arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover %) Total Plant 100

Phra mites australis 230 100

Description: Dense single species Phra mites swamp. 25m. Grading to dune grassland with El mus farctus, Potentilla anserina,Trifolium re pens, Lotus corniculatus, Planta o lanceolata,Galium verum.

n 16 u Kilkeran Lake

0 Site: Kilkeran Lake Transect code: B Location: Marginal swam Sample oint: 1 Aquatic - 5m out Sample area: 25m2 5x5 Substrate:Silt, sand G

Depth: 70 cm Salinit : 2arts per thousand NVC communit : ----- G Height (cm) Cover Total Plant 100 Hi her Plant 100 0

Potamo eton ectinatus 70 100 0

Algae 5 0 Enteromo ha 5

0 Description: Dense Potamo eton ectinatus bed extending from 1 -10m out. 0

0 Site: Kilkeran Lake Transect code: B Sample oint: 2 Marginal Location: Marginal swam 0 Sample area: lOm2 10x2 Substrate:Silt, sand

Depth: 0 - 40 cm Salinit : 2arts per thousand NVC communit :S21 Scius maritimus swam - Scir us mantimussub-community 0 Height cm Cover Total Plant 80 0 Scir us maritimus 100 80 Schoeno lectus lacustris ss tabernaemontani 120 < 1 0

Description: Fairly dense Scir us maritimus swam with sparse Schoenolectus. 4m. a

E

0

G

G n 17 J

Kilkeran Lake

Site: Kilkeran Lake Transect code: B Location: Marginal swam Sample point: 3 Marginal J Sample area: lOm2 10x1 Substrate: Not known

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 100

Irissuedacorus 100 10 A rostis stolonifera 20 80 Potentilla anserina 10 10 Fili endula ulmaria 70 5 L hrum salicaria 40 5 Rumex cris us 40 < 1 Carex otrubae 40 < 1

Description: Open, fairly patchy Iris cover with species-poor freshwater vegetation. 2m. Backing public road. Backing coniferous plantation.

ri lj Site: Kilkeran Lake Transect code: C Location: Freshwater inflow Sample point:1 Aquatic - 1 m out -ra nel Sample area: Grapnel only Substrate: Silt

Depth: 80 cm + Salinit : 2arts per thousand J NVC communit :----- Height cm Cover

Potamo etonectinatus

Description:

n u

18 I Lj U

Kilkeran Lake

0 Site: Kilkeran Lake Transect code: C Location: Freshwater inflow Sample point: 2 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 10 - 50 cm Salinit : 2arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Hei ht cm Cover 0 Total Plant 100

Phra mites australis 230 100 0

7 1 Description: Dense single species Phra mites swamp.-- 30m.

0 Site: Kilkeran Lake Transect code: C Location: Freshwater inflow Sample point: 3 Marginal Sample area: 20m2 20x1 Substrate: Silt a

Depth: 0 - 10 cm Salinit : 0arts per thousand

NVC communit : Undetermined Height cm Cover 0 Total Plant 100 0 Alnus lutinosa 500 10 Phalaris arundinacea 200 75 A rostis stolonifera 20 70 0 Potentilla anserina 15 10 Fili endula ulmaria 70 < 1 L hrum salicaria 50 < 1 0 Galium alustre 20 < 1 0 Description: lm strip of Phalaris dominated ve getation with Arostis dominant amongst a species-poor understore of freshwater plants. Occasional Alnuslutinosa. 0 Backing footpath. Backing Lolium erenne pasture. a

0

C

0

19 C Kilkeran Lake

3.3.4Evaluation

`Potentially Valuable'

Kilkeran is a medium-sized lagoon, mildly brackish at time ofsurvey (2 parts per thousand), with an interesting species composition.

Potamogeton pectinatus is abundant, occurring in extensive, dense beds to5-15 metres out from most of the eastern and western shores andcovering the entire water surface of the eastern bay.

Ruppia maritima occurs here but was found by grapnel surveynear the mouth of the outlet channel only. Its abundance and distribution is unknown.

A small amount of Chara aspera var. aspera was foundat the same location. Its abundance and distribution is also unkown.

Polygonum amphibium is occasional along the western shore.

Marginal vegetation comprises a narrow fringing strip of Scirpus maritimus, Schoenoplectus and Phragmites, each locally dominant along the eastern andwestern shores, with a broader band of Phragmites along the southernshore and an extensive Phragmites bed associated with the freshwater inflows in the north.

Kilkeran Lake presents a good, though seemingly species-poor example ofmildly brackish conditions. It is interesting to note the presence ofRuppia maritima and Polygonum amphibium in the same environment.

Further aquatic survey is recommended.

7 Lj

rl 20 u r a

MR r

Plate 12. IView of Kilkeran Lake looking north, Station C (on theleft) and D (on the right)

1 r

r

IN

a

Plate 32.2 View of Kilkeran Lake looking east, Station A (foreground) and B (distance) a rMM

41

r a r Plate 3_2.3 View of the outlet channel looking south toward the barrierof K lkeran Lake, Station L.

M

IN Plate 3.24 rme View of the barrier of Kilkeran Lake looking east fromthe sand dunes- a 9 Kilkeran Lake LJ

3.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork. J 3.4.1Site Description J Coastal brackish lake with road-bridge and inlet channel leading tocoarse sand beach barrier (Plate 1), with seawater incursion at high spring tide, andoutflow percolation at low tide (Plate 2). Lake shore with Phragmites communis and Schoenoplectus lacustrisstands, with virtually no unvegetated margin uncovered by water on southern shore,leading into extensive valley marsh. Small stands of Scirpus maritimus on sand behinddunes seaward of road, flooded during high spring tide.

Subsites (Fig.3.4.1)

1. Scirpus maritimus (W 337339) (Plate 3) Small area (c. 100 m2) of Scirpus maritimus with Triglochinmaritima grading into Potentilla anserina and grass, on sand immediately behind stable dune. Scirpusflooded at high spring tide. Salinity of near-shore water in adjacent channel was 2%0on 11 ix 1996.

2. Phragmites communis (L 368878) Lake shore beds of Phragmites communis on sand with litterand organic layer near lake outflow. Grading into area of Elymus athericus dominated vegetationon sand on floodplain.

3.4.2 Methods Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if:(1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

21 J

a

0

a

0

0

0

0

0

0

0

0

0

0

0

a

Fig. 3.4.1. Map of sampling sites (Carabidae and Staphylinidae) atKilkeran Lake, Co. Cork a

1 - Pitfall traps 2 - Pitfall traps, S-vac 0

D

0 Kilkeran Lake

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance). J Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992). J Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with J the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 3.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves.

UI

22 u

Kilkeran Lake a

D

TABLE 3.4.1. Details of sampling methods. 0

0 Method Details No. replicates Sampling period, etc. per unit sample 0 Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and 0 plastic funnels; collars used where cattle/horses occur Cobble samples Cobbles turned 0.5 - 2 m 30 0 from water margin 24 5 cm x 10 cm x 5 cm depth Flotation Samples taken where 0 burrow casts observed; agitated soil floated in water Ground search Search of bare soil (< 50% 1 1 hour 0 vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to 0 a sufficient extent (> severalm2) at the site. Sampling involved a fixed time groundsearch (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. 0 Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are 0 representative of the sites, even if spring species may beabsent. 0 Variety of sampling techniques

Several techniques will always give a more robust picture ofthe fauna of a site, 0 because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is a regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the 0 site. 0

0

23 0 Kilkeran Lake

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

J Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the J National Museum of Ireland, and specimens ofmany of the other species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. J Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : Scirpus maritimus area- S-vac suction sampler (11 ix 1996), c. 2 m2; Scirpus maritimus area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (18 viii- 11 ix 1996); Phragmites communis area- 6 pitfall traps (11 ix - 5 x 1996);

No Bledius burrow casts were observed on the sandy marginsof the channel behind the sand barrier.

J 24 J

Kilkeran Lake 0

Species were selected as indicators of conservation value if: (1)they have a restricted habitat 0 preference to a specific type of microhabitat associated with thelagoon margins, and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. a

3.4.3Survey Results 0 Nine species of carabid and seventeen species of staphylinid wererecorded, three species of which are regarded as indicator species (Table 3.4.2). 0

TABLE 3.4.2.Carabidae and Staphylinidae (Coleoptera) recorded from Kilkeran Lake. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), andBooth 0 (1988) for Tachyporus dispar. 0 Species No. individuals Carabidae 0 Abax parallelipedus (Pill.Mitt.) 3 Agonum pelidnum (Payk.) 2 Bembidion assimile Gyll. 12 0 Blethsia multipunctata (L.) 1 Indicator species Bradycellus harpalinus (Serv.) 1

Carabus granulatus L. 1 Dromius linearis (01.) 3 0 Pterostichus niger (Schall.) 124 Pterostichus nigrita (Payk.) 1 0 Staphylinidae

Anotylus rugosus (F.) 1 Atheta amplicollis (Muls. Rey) 13 0 Atheta clientula (Er.) 1 Atheta fungi (Grav.) 1 Atheta graminicola (Grav.) 6 0 * Gabrius keysianus Sharp 1 Indicator species * Philonthus fumarius (Grav.) 6 Indicator species Philonthus micans (Grav.) 1 0 Sepedophilus nigripennis (Steph.) 4 Stenus cicindeloides (Schall.) 2 Stenus juno (Payk.) 5

Stenus picipennis Er. 1 a

Tachinus signatus Grav. 1

Tachyporus chrysomelinus (L.) 1 Tachyporus dispar (Payk.) 2 0 Tachyporus pusillus Grav. 3

Xantholinus longiventris Heer 1 0 Blethsia multipunctata appears to be local in Ireland: It islisted without annotation by Speight et al. (1982); there are recent records from turloughsin south Galway (Lott and Bilton 0 1991, J.A. Good unpublished). It occurs in fens and lakemargins (Hyman and Parsons 1992), especially on shores of slow-moving and still water (Koch 1989).The species is widespread 0

25 E J Kilkeran Lake

but local and possibly declining in Great Britain, according toHyman and Parsons (1992), and very rare in Central Europe (Freude 1976).

Gabrius keysianus is a halobiont ripicolous species (Koch 1989), widespreadbut local in England and Wales (Hyman and Parsons 1994), and generally localand mostly rare in western Europe (Horion 1965). It has been previously recorded in Ireland(O'Mahony 1929), and was found at three other sites during this survey, which wouldbe expected given its habitat.

Philonthus fumarius appears to be widespread but local in Ireland(Johnson and Halbert 1902, Lott and Bilton 1991) and Great Britain (Hyman and Parsons1994). It is not rare in Central Europe, but rather rare eslewhere (Horion 1965). The species occursin marshes including muddy and marshy freshwater shores (Horion 1965, Koch 1989) andespecially on coastal marshes (Hyman and Parsons 1994).

3.4.4Evaluation

Of average conservation interest for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating

The presence of three indicator species indicates conservation interest.

J 3.4.5References Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Freude, H. (1976) Fam. Carabidae. In: Freude, H., Harde, K.W.and Lohse, G.A. (eds). Die Kdfer Mitteleuropas. 2. Goecke & Evers, Krefeld. Horion, A. (1965) Faunistik derMitteleuropdischen Kdfer. X. Staphylinidae: Paederinae bis Staphylininae. Feyel, Oberlingen-Bodensee. Hyman, P. S. and Parsons, M. S. (1992) A reviewof the scarce and theatened Coleoptera of Great Britain. Part 1. UK Nature Conservation Series No. 3,Joint Committee for Nature Conservation, Peterborough. Hyman, P. S. and Parsons, M.S. (1994) A review ofthe scarce and theatened Coleoptera of Great Britain. Part 2. UK Nature Conservation Series No. 12,Joint Committee for Nature Conservation, Peterborough. Johnson. W.F. and Halbert, J.N. (1902) A list of thebeetles of Ireland. Proc. R. Ir. Acad. (3) 6: 535-827. Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die Kdfer Mitteleuropas. 12.1. Supplementband mit Katalogteil. Goecke & Evers, Krefeld. Lott, D.A. and Bilton, D.T. (1991) Records of Coleoptera fromIrish wetland sites in 1989. Bull. Ir. biogeog. Soc. 14-.60-72. Lucht, W.H. (1987) Die Kdfer Mitteleuropas. Katalog. Goecke & Evers,Krefeld. O'Mahony, E. (1929) Coleoptera. In: Praeger, R.L. (ed.) Reporton recent additions to the Irish fauna and flora. Proc. R. Jr. Acad. 39(B): 22-36. J Speight, M.C.D., Anderson, R. and Luff, M.L. (1982) An annotatedlist of the Irish ground beetles (Col., Carabidae + Cicindelidae). Bull. Ir. biogeog. Soc. 6:25-53.

26 Kilkeran L. 4 a

r rno

Plate 1 Sand beach barrier at Kilkeran Lake, Co. Cork r

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im r rdo r01

Plate 2 Outflow percolation at Kilkeran Lake, Co. Cork go

IN Kilkeran L. 5

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46 r

Plate 3 Subsite 1 - Scirpus matitima area at Kilkeran Lake, Co.Cork r

IN

0

0 Kilkeran Lake

3.5 SUMMARY AND EVALUATION

Kilkeran Lake is a medium-sized (16 ha) natural sedimentary lagoonand is therefore of international importance based on the Habitats Directive.

The lake lies within a proposed NHA (Site Code No.1061). The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology High Aquatic Fauna High Vegetation Potentially High Ecotonal Coleoptera Average

J Geomorphology Kilkeran Lake is a medium-sized natural sedimentary lagoon. Barrier morphologyis well documented and studies of its history are ongoing. The lagoon lies within an area of relatively unspoilt sanddunes and, although small (c. 16 ha.) is probably the best example in thesouthwest of Ireland of a lagoon with a sand/gravel barrier. The lake is rated as of high conservation value asa good example of sedimentary lagoon with a sand/gravel barrier in an almost natural state. Aquatic Fauna A total of 31 taxa including 6 lagoonal specialists wasrecorded. For such a relatively small lake, the aquatic fauna appears to be diverse andinteresting. Hydrometra gracilenta was identified from specimens collected by Galvin (1992).This is a first record for Ireland and was not found at any other site.Other interesting J species include Notonecta viridis, and Sigara concinna which is describedas rare in Ireland but was found also at Lady's Island L. andTacumshin L. during this survey and in Kilkeran L. was extremely abundant and the dominantspecies. Both Neomysis integer and corixids were more abundant in this lake thanat any other site sampled during the survey. This is the only site at whichthe beetles Anacaena lutescens, Cercyon marinus and Coccidula rufa were recorded but details oftheir distribution in Ireland are not known at present. Galvin (1992) recorded 44species of aquatic fauna in 1991, including the rare lagoonal bryozoan Victorella pavida whichmay have been misidentified. Other interesting species include the two freshwater bryozoans, oneof which may be new to Ireland.

27 Kilkeran Lake

The lake is regarded as of high conservation value forits relatively high species richness and high proportion of lagoonal specialists and the presenceof some rare species

Vegetation

Potamogeton pectinatus is abundant, occurring in extensive, dense beds to5-15 metres out from most of the eastern and western shores andcovering the entire water surface of the eastern bay. Ruppia maritima occurs here but wasfound by grapnel survey near the mouth of the outlet channel only. Its abundance anddistribution is unknown. A small amount of Chara aspera var. aspera was foundat the same location. Its abundance and distribution are also unkown. Polygonum amphibium is occasional along the western shore. rl Marginal vegetation comprises a narrow fringing strip of Scirpus maritimus, J Schoenoplectus and Phragmites, each locally dominant along the eastern andwestern shores, with a broader band of Phragmites along the southernshore and an extensive Phragmites bed associated with the freshwater inflows in the north.

Kilkeran Lake presents a good, though seemingly species-poor example ofmildly brackish conditions. It is interesting to note the presence ofRuppia maritima and Polygonum amphibium in the same environment.

J The lagoon is regarded as "potentially valuable" as a fullsurvey of aquatics was not possible. Further aquatic survey is recommended.

J Ecotonal Coleoptera

Nine species of carabid and seventeen species of staphylinid wererecorded, three species of which are regarded as indicator species

Blethsia multipunctata appears to be local in Ireland, although thereare recent records from turloughs in south Galway. It occurs in fens and lakemargins, especially on shores of slow- moving and still water. The species is widespread but localand possibly declining in Great Britain, and very rare in Central Europe.

Gabrius keysianus is a halobiont ripicolous species, widespread but localin England and

Wales, and generally local and mostly rare in western Europe. It has been previously recorded in Ireland, and was found at three other sites duringthis survey, which would be expected given its habitat.

Philonthus fumarius appears to be widespread but local in Irelandand Great Britain. It is not rare in Central Europe, but rather rare eslewhere. The speciesoccurs in marshes including muddy and marshy freshwater shores and especially on coastal marshes.

The presence of three indicator species indicates average conservation interestfor terrestrial ecotonal community.

28 1 Kilkeran Lake 0

Summary 0 Kilkeran Lake is a natural sedimentary lagoon lying within anarea of relatively unspoilt sand dunes and, although small is probably the bestexample in the southwest of Ireland of a lagoon with a sand/gravel barrier. 0 For such a relatively small lake, the aquatic fauna appearsto be diverse and includes several rare or interesting species. 0 In conclusion, based on geomorphology and aquatic fauna, and potentiallyon vegetation, the lagoon is of high conservation value and recommendedas a proposed SAC. 0

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0 29 J

COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

J 4. LISSAGRIFFIN LAKE

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

LA

Prepared for the National Parks and Wildlife Service

(BioMar/Life) J

4. LISSAGRIFFIN LAKE

CONTENTS

4.1 Study Area

4.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

4.2.1Methods 4.2.2Results 4.2.3Discussion 4.2.4Threats 4.2.5Evaluation 4.2.6References

4.3 Vegetation Survey (Pat Hatch)

4.3.1Site Description 4.3.2Methods 4.3.3Results Shore based survey Transect tables 4.3.4Evaluation

4.4 Ecotonal Coleoptera (Jervis Good)

4.4.1Site description 4.4.2Methods 4.4.3Results 4.4.4Evaluation 4.4.5References

5.5 Summary and Evaluation Lissagriffin Lake

4. LISSAGRIFFIN LAKE, Co. Cork.

OS Grid Reference: V 775 265, 1:50,000 Sheet No. 88 Alternative names: Lissagriffin Lough

4.1 STUDY AREA

General features

Lissagriffin Lake is situated at the western end of theMizen peninsula, 5 km west of Crookhaven (Fig. 4.1.1). The lake lies at the landward endof a long sinuous tidal inlet and is partly artificial in that it now lies behinda causeway, but at the mouth of the inlet is a dune barrier through which the combined actionof river and sea has cut a channel. The lake is very shallow and seawater enters onall tides but a relatively large amount of fresh water also flows through the lake. The lake is of great ornithological interest for the numberof vagrant American waders that are recorded but it is also of value asa feeding area for small numbers of waders and wildfowl, including Whoopers and Bewick's swans, especially during hard weather (Hutchinson 1994).

The lake is part of a proposed NHA (Site CodeNo. 1040) which includes the coastal dunes and rocky hillsides.

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) Ei The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is >7°C in January and15-15.5°C in July. The growing season (the period of mean daily air temperatures above 6°C) is 11 months and as snow and frosts are rare, some plant growth is possiblein winter months. Annual Ei rainfall is approximately 1200 mm, and the number of raindays (1 mm or more) is approximately 175. Winds are mainly from the south and southwest.Mean annual hourly wind speeds are between 5 and 6 m/s anda maximum wind speed of 49-50 m/s is estimated to occur once in 50 years. The dailyduration of bright sunshine averages 3.5-4.0 hours. Mean relative humidity is around 85% as onall Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8in (Carter 1992). Maximum Ei wave heights (averaging once in 50 years) are 25-30 in(Couper 1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS) at Bearhaven is 3.1m (Admiralty Tide J Tables). Sea temperatures are lowest in February and highest inAugust. Landscape and Geology Bedrock is Old Red Sandstone with outcropsof slate and shale. To the west of the lake are lime-rich dunegrasslands but on the other three sides J land is a mixture of rocky hillside, small peat bogs,wet heath and small fields of pastureland. Soils are generally acidic and mostly peaty podzols andacid brown earths

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cI Fig. 4. 1.1Section of 150 000 map showing locality of Lissagriflin Lake 0 n J

Lissagriffin Lake

(Royal Irish Academy 1979). Agricultural use of the land hasdeclined and many of the fields have reverted to heath.

Lake Topography The area of the lake above the causeway is roughly600 in from J southwest to northeast, width varies from 200 to 300 m,and area is approximately 12 ha. The lake is very shallow, mostly less than 1m and most of the bed of the lake is sand with softer organic muds away from the main riverand tidal channel which runs through the lake.

Hydrology Two small streams enter the lake from the east andseawater appears to enter on every tide through a bridge in the causewaywhich carries the road and on higher tides through a series of pipes along the causeway.There is a tidal variation in water level of the lake of about 30 cms onneap tides, measured at the bridge. Unlike on the open shore where spring tides produce extremes ofhigh and low water, a time lag at the head of the inlet means that atspring tides the water level in the lake remains at a higher level during both high and low tidebut with a similar tidal variation in height.

Salinity and water quality Seawater at approximately 34 %o enters the lake twice J daily but most of it also leaves again leaving partsof the substrate exposed. Fresh water enters from two streams in the east and thevolume of fresh water entering J appears to keep salinities relatively low except during spring tides. The only major source of nutrients to the lake isagricultural. The amount is likely to be low in this area and regular flushing by seawateris likely to prevent any eutrophication problems.

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Lissagriffin Lake J

4.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver, Dept. of Zoology, University College Dublin J 4.2.1. Methods

Environmental variables Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %a. precision). A photographic record was made of the site andlocal information sought concerning the background and recent history.

Faunal Sampling. Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988)Faunal samples were preserved in 70% alcohol and stored for subsequent sorting andidentification. Fyke nets were used at stations A and B inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of

3 LI

Lissagriffin Lake 0 the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution 0 within the water column. Abundance categories of present, common andabundant are purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were 0 used to identify remaining specimens, but many of these werelarval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for identification and these were often not available due to lowpopulation density and the IJ limited number of individuals collected in the time available (egJaera, hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify whenpreserved (turbellarians, leeches). IJ All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same 0 species.

4.2.2Results 0

Lissagriffin Lake was sampled on 4.vii.96 during the first partof the survey, and from 0 29-31.vii.96 during the more intensive survey. Positions of the samplingstations are shown in Fig. 4.2.2. 0 Environmental Variables Station A (OS 7720 2642) was located at the southwestend of the lake, east of the bridge in the causeway. Substrate consisted entirely of sand, waterdepth varied from 0 0 - 2 m and salinity measured 28 %o on theflood tide and 6 %o during low tide. Station B (OS 7734 263 1) was located at thesouthwest end of the lake but at the 0 southern end of the causeway (Plate 4.2.2). Substrate consisted offine sand and organic mud, water depth varied from 0- 25 cm and salinity measured 8 %o (Plate 4.2.3) 0 Station C (OS 7748 2628) was located along the southernshore of the lake where a small stream enters. Substrate was fine sand and organic mudwith scattered stones, 0 water depth was 0 - 10 cm and salinity measured6 %o. Station D: (OS 7760 2636) was located along the southernshoreline where a rocky outcrop extends into the lake. Substrate consisted of shaly rocksand stones of various 0 sizes and soft mud, depth varied from 0 -10 cmand salinity measured 8 %o Station E (OS 7740 2663) was located midway along thenorthern shore where a fresh 0 water stream enters. Substrate consisted rock, stones and gravel withsoft organic mud. Water depth varied from 0- 40 cm and salinity measured 4 %o. Station F (OS 7767 2661) was located in the northeastof the lake among 0 Phragmites. Substrate consisted of peat on sand, water depth variedfrom 20 - 80 cm and salinity measured 6 %o. 0 Station G (OS 7779 2656) was located in the mosteasterly part of the lake where a freshwater stream enters. Substrate was gravel and sand with peatand soft mud, water depth varied from 20 - 80 cm, and salinity measured8 %o. 0

0 4 0 Plate 1 Upper lake - Lisagriffin, Co. Cork 41 IN

go Plate 42.1View of Lissagriffin Lake looking east. I" J

r

0

0 Plate 4.22View of the tidal inlet below the causeway of LissagriffinLake, Station H me

Plate 42.3View of one of the pipes leading through the causewayof Lissagriffin Lake, Station B

0

Plate 4.2.4 View of the sandhills at the mouth of the inletLissagriffin Lake. J

77 78

Cork J Fig. 4-2. Location1. Map of Sampling Stations in Lissagriffin Lake, Co.

J 0 Table4.2.1Fauna Recorded at Lissagriffin Lake, CoCork.July and August 1996. 0 Sampling Stations ( L.T. = light-trap) AL.T. 11 CL.T. D L.T.D EiI.T.EI FLT.F G 11 0 Porifera -f Cnidaria ------I------+-- --- Turbellaria - 0 Nemertea 1

Annelida Hediste diversicolor a a a + I a Crustacea 0 ? I- - -- Ostracoda - -- 1 Cirripcdia Mysidacea Neomysis integer c >100 c o 75 o n 5 c 7S c c n Isopoda Jaera nordmanni + Ligia oceanica + AmphipodaAllomelita pellucida + 0 Gammarus duebeni + c Melita palmata + + Orchestia ganunarella + + + 0 Tanaidacea DecapodaCarcinus maenas c c c + c c Crangon crangon a 0

Palaemonetes varians c 2 c 1 a Palaemon elegans 2 c P.serratus a 0 Atachnida Insecta Thysamura Petrobius sp. + 0 hemeropte ra Cdonata Plecoptera 0 Trichoptera Hemiptera Sigara stagmdis + Coleoptera 0 Diptem Chironomidae + + Mollusca - I ---- 0 Prosobranchia Hydrobiidae shells shells shells + 0 0

Hydrobia ulvae shells j + Potamopyrgus antipodarum shells shells I + + 0 isthobranchia i

Pulmonata I i BivalviaCeastodermaedule shells hells 0

I Macomabaltica shells I I i stxlls

Scrobicularia plan shells, I shell

Bryozoa ? Plumatella repens ! + 0 Echinodermata r

Tunicata I

F. 1 i Teleostei Anguilla anguilla _ ------+- -1------µ--I- + I----- 0 + o + - + 0 1 + +rc Gasterosteus aculeatus

Mugilidae F. I - j--+ + Pomatoschistus microps + 0 c Platichih s Jlesus + + ; c

+ = present; o = occasional; a = abundant; F= fyke net 0 Lissagriffin Lake J Station H (OS 7715 2633) was an additional sampling stationin the tidal inlet west of J the causeway (Plate 4.2.2). Substrate was sand, grading to finesilt and organic mud. Water depth varied from 0 - 25 cm and salinitymeasured 25 %o. on the flood tide.

Fauna The species recorded at the different stations, using all sampling methods, are listed in Table 4.2.1. Among 24 taxa listed, 21 are identified tospecies. Three of the species J are marine, 3 are poly-mesohaline, 11 are euryhaline, 1 isoligo-mesohaline and one is limnic (Table 4.2.2). Two species (Sigara stagnalis and Palaemoetes varians)are listed as a lagoonal specialists in Britain (Davidson et al.1991). Marine species were only present in the tidal inlet (stationH). Landward of the causeway, species occurrence was similar at all stations but some species e.g. prawns and mysids, were most abundant at A and B i.e. near the causeway. Corixids, chironomid larvae and Potamopyrgus antipodarum were only found at E,F and G, the most inland stations, although the salinity was not significantly lowerat these stations than elsewhere at the time of sampling. Although no light traps were set at H, 17 specieswere recorded here compared with J 11 at A, 9 at B and 2-6 at otherstations, showing that diversity increases with increasing marine influence.

Table 4.2.2Ecological categories of the recorded taxa in Lissagriffin Lake (marginal species omitted). L = lagoonal specialist (Davidson et al. (1991)

Marine Hydrobia ulvae J Palaemon elegans P. serratus

r"1 Poly-mesohaline Crangon cangon J Melita palmata Mugilidae

Euryhaline Hediste diversicolor Neomysis integer Jaera nordmanni 7lJ Gamniarus duebeni Palaemonetes varians L Sigara stagnalis L Carcinus maenas Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps Platichthvs flesus

Oligo-mesohaline Potamopyrgus antipodarum

Limnic ?Plumatella repens n J

J 5 U

Lissagriffin Lake 0

4.2.3Discussion 0 Despite the low salinities recorded at the time of samplingin August, the fauna typifies a brackishwater of medium to high salinity with open accessto the sea. The poor representation of oligohaline species, even at the stations furthest fromthe sea, may be 0 due to poor growth of submerged macrophytes caused by overheatingin shallow water and possibly tidal scouring. However, the frequency of ragworms throughoutthe lake 0 suggests that the lake bed is not exposed or overheatedfor long periods. When the presence of a sea inlet is taken into account, thelake may be described as poor in species. 0 None of the recorded species can be described as rarein Ireland

4.2.4Threats 0

There appear to be no major threats to this lakeat present. The amount of nutrients 0 from agricultural sources is likely to be low in thisarea and regular flushing by seawater could prevent any eutrophication problems. However, there are holiday homes on land surrounding the lake and uncontrolled camping andcaravanning has 0 caused some problems. The County Council has recently acquired partof the dunes by compulsory purchase. 0 The lake is subject to changes from natural processes, especiallyfrom colmatisation, and is likely to become increasingly shallow. 0 4.2.5Evaluation 0 Lissagriffin Lake is an artificial saline lake created by constructionof a causeway at the head of a tidal inlet. 0 Geomorphologically and ornithologically the area is great interest. However thelake is largely artificial and the aquatic fauna recorded in the surveyis relatively poor and of little interest. 0 The lake and tidal inlet are likely to be protectedfor their ornithological value. Hides could be built to reduce disturbance and traffic congestion onthe causeway. 0 The lake lies within a proposed NHA (Site Code No.1040). In conclusion, based on the aquatic fauna, Lissagriffin is notof high conservation 0 value.

4.2.6References and Additional Sources of Information 0

Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department 0 Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. 0

0 6 Lissagriffin Lake

Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 23 5-23 8. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. 7 Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Lj Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. rl 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFAIT23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp

J 7 J Lissagriffin Lake

4.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

4.3.1Site Description (Fig. 4.3. 1)

This is a long narrow shallow lagoon bordered by fairlyhigh ground to the north, east, south east and west. This is an area of roughpasture with occasional heath vegetation. The outlet to the sea lies at the western endof the site and runs through dune grassland.

The major freshwater inflows discharge into the lake at theeastern end from the north and east. The associated Phragmites bedsare the only areas of extensive swamp vegetation. Elsewhere, shores are generally rocky andmore or less steeply sloping with occasional narrow strips of emergents to the north andopen and very shallow of slope to the south. Heath vegetation occurs above much ofthe northern shore and saltmarsh occurs along most of the lower lying, sandy southernshore.

A causeway carries a public road across the lake aboutmid-way along its length and another borders the north eastern corner, with the road continuingalong above the north shore.

4.3.2 Methods J Two survey methods were employed in thecourse of fieldwork: 1. Transects J 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 4.3.2.

Each transect ran from the aquaticzone, through adjacent marginal areas, to the adjacent habitat. Aquatic and marginalareas were sampled using quadrats or releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in somecases, on the depth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. Theaverage height and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

8

1 DomlvsdyA ' species codes : i - - 5wariPlre,-,5+01le wdU 5war5lacPUU5 - 5cirpus wdri}ivW5 - 5ckoenoplecfu5Pkragwti e5 Qk5frd (i s n 77 0 0 °o c 0l - Sct lf M drsh PmdrSuyCl rep - - I HookenYuLICLIvleltl(S peploiJcs W1ar Ssp, fd bei-tea i irA f F uJ s I'll' - PUu5/ 5wtar ////hclu5 Swdr SlucII/!llrll / / ill IIII I ill I, Illl 1III15,-nurPuu5 Smdr/ Pr cl 5 w 51dc $r1ar I II uus Say o ° 0 5C,77 0 0 0 0 0 o Pmdr / /P Hp 00000000 n 0 °0 _ _ 0 °0 o 0000 D O O D D O D O D O Fig. 4.3.1. -.i 55oJrlrigi n LlCO D O D C O O O O P. , Go Cork - Marginal Vp ref to D =-J U U U 1-3 C _J C I C___] L] C_] U L7 C_3 C-] C-7 C-3 C-] U C_3 U C- N A-TTA - TO Po: J5 0 rh649e Tr4nsecf5 in ve9efafion

To N'_ Sea Fig. 4.3.2. Lissagriff in Lake, Co. Cork: Shore-based Survey Sections Location of Transects and 0

Lissagriffin Lake 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for a other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 0 6 26-33 % 5 11-25 % 4 4-10 % 0 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals 0

0 9

0 J Lissagrifn Lake

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % IV 61-80 % III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall 7 Herb Fen' volume. J Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transectswere located at the outlet to the J sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The resultsare presented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of changeare marked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon. J Constraints

Time. Restrictions on the time available in which tocarry out this survey had the following consequences:

10 u

Lissagriffin Lake 0

a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores. 0

Identifications 0 Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0 Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of 0 Britain and Ireland: Stoneworts' (1992).

Evaluation 0

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `Valuable' .site is one that is shown to beof particular interest and that is considered to be worthy of conservation/protection. 0

0 11 0 J

Lissagriffin Lake

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable' site is one that is shown tobe of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

4.3.3 Results J 1.Shore-based survey

Section A-B

Aquatic: No aquatic vegetation to at least 20m out

Sand substrate J Marginal:Open Scirpus maritimus cover with salt tolerant vegetation dominated by Puccinellia maritima and Glaux maritima. c. 100m. Poached and grazed Grading to salt tolerant community dominated by Festuca rubra, Juncus gerardii and Agrostis stolonifera with sparse Scirpus maritimus and Juncus maritimus. c.2-300m. Poached and grazed

Adjacent:Dune grassland dominated by Festuca rubra, Trifolium repens, Plantago ------,lanceolataGalium verum- J ------Section B-C (Transect A)

Aquatic: Unchanged

J Marginal:Salicornia dominant with patchy Puccinellia maritima in species-poor salt tolerant community on sandy substrate. 40-50m Festuca rubra dominant with Glaux maritima locally co-dominant in J species-poor salt tolerant community on sandy substrate. 30-40m

Adjacent:Dune grassland dominated by Ammophila arenaria and Festuca rubra

Section C-D

Aquatic: Ulva lactuca - sparse

Marginal: 1-2m strip of open Honkenya peploides cover on sand Backing to Festuca rubra - Glaux maritima dominated community asB-C. 5-70m

Adjacent:Unchanged

12 u

LissagrifTin Lake 0

Section D-E 0 Aquatic: Unchanged

Marginal:As B-C 0

Adjacent:2.5m earth cliff 0 Backing to pasture

Section E-F 0 Aquatic: Enteromorpha Ulva lactuca 0 Marginal: Single species Phragmites australis swamp. 3-20m a Adjacent:Heath vegetation dominated by Ulex europaeus, Pteridium aquilinum and Erica cinerea on 45 degree slope to public road 0 Section F-G

Aquatic: Enteromorpha - patchy a Ulva lactuca - patchy Fucus c.f spiralis - patchy 0 Sand substrate with occasional cobbles

Marginal:Single species Scirpus maritimus swamp. 3m a

Adjacent:3m stone wall backing to public road a Section G-H (Transect B)

Aquatic: Unchanged

Marginal:Bedrock shore with sparse salt tolerant vegetation dominated by Festuca D rubra

Adjacent:As E-F 0 Section H-I

Aquatic: Enteromorpha - patchy a Ulva lactuca - patchy

Marginal:5m concrete wall 0

Adjacent:Public road 0

0

13 0 J

Lissagritfin Lake

Section I-J

Aquatic: Unchanged

Marginal:Scirpus maritimus and Phragmites swamp vegetation with each species locally dominant in small single species stands. c.5m

Adjacent:As E-F

Section J-K

As G-H

Section K-L

Aquatic: No aquatic vegetation to at least 15m out

Marginal:Single species Phragmites swamp. 15-20m ri J Adjacent:As E-F

Section L-M

Aquatic: Unchanged

Marginal: 1 m stonewall

Adjacent:Amenity grassland (private garden)

7 Section M-N J Aquatic: Unchanged

Marginal:Single species Phragmites swamp. 15-20m

Adjacent:Unchanged

Section N-O

Aquatic: Unchanged

Marginal:2m stone causeway wall

Adjacent:Public road on causeway backing to extensive Phragmites bed associated with freshwater inflow J

14 0 Lissagriffin Lake 0

Section O-P (Transect Q 0 Aquatic: Filamentous algae- patchy Enteromorpha - very sparse 0 Silt and sand substrate 0 Marginal:Dense single species Phragmitesswamp. c.50-60m Grading to dense Phragmites dominated fen community withsparse species-poor understorey of freshwater species associated with 0 freshwater inflow. c.2-300m

Adjacent:Public road to north, heath as E-F and pastureto south and east 0 ------

Section P-O 0

Aquatic: Ruppia sp.- sparse and low growing to at least 20m out Filamentous algae- sparse 0 Enteromorpha- sparse

Marginal:Dense single species Phragmitesswamp. 25-30m 0 Backing to 45 degree bedrock shore

Adjacent:Heath as E-F 0 ------

Section Q-R 0

Aquatic: Unchanged C

Marginal:Scirpus maritimus and Schoenoplectus lacustrisssp tabernaemontani swamp with 0 each species locally dominant.c. IOm Grading to 1-2m Agrostis stolonifera dominated strip withfrequent Eleocharis 0 palustris, Glaux maritima, Atriplex hastata

Adjacent:1.5m stone wall backing to rough pasture 0 ------

0

0

0

0 15

0 Lissagriffin Lake J Section R-S (Transect D)

Aquatic: Ruppia sp. - sparse and low growing from c.50m toat least 100m out Enteromorpha - very sparse 9 J Sand substrate

Marginal:Open Scirpus maritimus cover with frequent Phragmites shoots over salt tolerant community with occasional Juncus maritimus tussocks. Agrostis 7 stolonifera and Eleocharis palustris patchy and locally dominant among J otherwise sparse understorey species. Poached and grazed. 20-40m Grading to fairly dense Schoenoplectus cover with frequent Phragmites and Scirpus maritimus over species-poor salt tolerant community. Agrostis and Eleocharis as above. Poached and grazed. 10-20m Grading to open Schoenoplectus cover over sparse freshwater species on heavily poached substrate. Grazed. 40-50m

Adjacent:Phragmites fen associated with freshwater stream. c.20m Backing to rough pasture ------Section S-T

Aquatic: Unchanged

Marginal:Fairly open Schoenoplectus cover with sparse Phragmites shootsover species-poor salt tolerant community. Abundant Glaux maritima dominant below with patchy Agrostis stolonifera and Eleocharis palustris J locally co-dominant among sparse understorey. 30-50m Grading to Iris psuedacorus dominated community of sparse freshwater species on heavily poached substrate. Grazed. c.70m

Adjacent:Rough pasture ------Section T-A

Aquatic: Unchanged

Marginal:As A-B

Adjacent:Unchanged ------

16 0

Lissagriffin Lake 0

1. Transects 0 Site: Lissa riffin Lake Transect code: A

Location: Saltmarsh bordering outlet channel Sample point: 1 Aquatic - IOm out Sample area: 25m2 5x5 Substrate: Sand 0

Depth: 70 cm Salinit : 19arts per thousand NVC communit :----- 0 Height cm Cover %)

0 [Descri tion: No aquatic vegetation. 0

0 Site: Lissa riffin Lake Transect code: A Location: Saltmarsh bordering outlet to sea Sample oint: 2 Marginal 0 Sample area: 100m2 10x10 Substrate: Sand

Depth: ----- Salinit : ----- NVC communit :Undetermined 0 Height cm Cover Total Plant 95 0

Salicornia a . 8 80 Puccinellia maritima 5 20 0 Planta o maritima 8 < 1 S erlaria marina 6 < 1 Juncus maritimus 70 < 1 0

Description: Salicornia dominant with open patchy cover of Puccinellia inspecies-poor salt tolerant community. 50m. 0

0

0

0

0

a 17 J rl Lissagriffin Lake J

Site: Lissa riffin Lake Transect code: A Location: Saltmarsh bordering outlet channel Sample point: 3 Marginal n Sample area: 100m2 4x4 Substrate: Sand

J Depth: ----- Salinit : ----- NVC communit :Undetermined Height (cm) Cover (%) Total Plant 75 n J Festuca rubra 10 50 Glaux maritima 8 20 A rostis stolonifera 8 5 Carex extensa 15 5 Planta o maritima 6 < 1 Planta o corono us 2 < 1

Description: Species-poor salt tolerant community with Festuca rubra d ominantand Glaux widespread and locally co-dominant. 40m. A small outflow channel (average width 4m asses through this community and connects with the main outflow. Grading to Ammo hila arenaria - Festuca rubra dune grasslandbarrier).

Site: Lissa riffin Lake Transect code: B

Location: Open rocshore Sample point: 1 Aquatic - 5m out Sample area: 25m2 5x5 Substrate: Sand, cobbles J Depth: 80 cm Salinit : 19arts per thousand

NVC communit : ----- Height cm Cover Total Plant 70

Fucus c.f s iralis 25 30 Enteromor ha 20 20 Ulva lactuca 30 20

Description: Patchal al cover growing on submerged rocks. Backing rock shore with sparse vegetation. Festuca rubra dominant withsparse Armeria maritima, Planta o maritima, Glaux maritima on exposed bedrock(slope c.45 degrees). Grading to heath vegetation dominated b Ulex euro aeus andPteridium a uilinum.

18 0

Lissagriffin Lake 0

Site: Lissa riffin Lake Transect code: C 0

Location: Freshwater inflow Sample point: 1 Aquatic - IOm out Sample area: 25m2 5x5 Substrate:Silt, sand 0 Depth: 20 cm Salinit : 8arts per thousand NVC communit :----- Height (cm) Cover 0 Total Plant 5

Filamentous algae 5 0 Enteromo ha < 1 0 Description: Sparse cover of filamentous al gae and Enteromor ha.Same sp ecies at more or less same cover 0-15m out. 0

0

Site: Lissa riffin Lake Transect code: C 0 Location: Freshwater inflow Sample point: 2 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 0 cm Salinit : ----- 0 NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover 0 Total Plant 100 Hi her Plant 100 0 Phra mites australis 230 100

Algae 10 0

Enteromo ha 10 0

Description: Dense single species Phra mites swam with open roundcover of washed u 0 Enteromor ha. 60m.

0

0

0

0

19 C Lissagriffin Lake lJ

Site: Lissa riffin Lake Transect code: C Location: Freshwater inflow Sample point: 3 Marginal Sample area: 100m2 10x10 Substrate: Peat

. Depth: 0 cm Salinit : ----- NVC communit :S4 Phra mites australis swam - Galium alustre su -community Height cm Cover Total Plant 100

Phra mites australis 230 100 Mentha a uatica 30 < 1 L hrum salicaria 40 < 1 Galium alustre 20 < 1 Nasturtium officinale 15 < 1

Description: Dense Phra mites fen with s parse understore offreshwater s pecies. c.100m Backing to heath vegetation with Ulex euro aeus and Pteridiuma uilinum J

Site: Lissa riffin Lake Transect code: D

Location: Marginal swam Sample point: 1 Aquatic - 100m out Sample area: 25m2 5x5 Substrate: Sand

Depth: 20 cm Salinit : 6arts per thousand NVC communit :----- Height cm Cover (%) n Total Plant 5 j Hi her Plant 5 n I Ruis s p. u 8 5

Algae < 1 J Filamentous algae < 1

Description: Sparse low growing Ru n is with very sparse filamentous algae. Same species at j more or less same cover 60 - 100m out.

20 0

Lissagriffin Lake 0

Site: Lissa riffin Lake Transect code: D 0 Location: Marginal swam Sample oint: 2 Aquatic - 50m out Sample area: 25m2 5x5 Substrate: Sand 0 Depth: 15 cm Salinit : 6arts per thousand NVC communit :----- Height cm Cover (%) 0 Total Plant 5

Filamentous algae 5 0

Description: Sparse filamentous algae only. 0

0

Site: Lissa riffin Lake Transect code: D 0 Location: Marginal swam Sample oint: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat Depth: 0 cm Salinit: ----- a NVC communi : S21 Scius maritimus swam - A rostis stolonifera sub-community Height cm Cover Total Plant 75 0

Scius maritimus 100 60 0 Phra mites australis 80 5 Eleocharisalustris 15 5 Glaux maritima 8 5 0 A rostis stolonifera 15 5 Juncus maritimus 70 < 1 Juncuserardii 20 < 1 Tri lochin maritima 15 < 1 Aster tri olium 25 < 1 Samolus valerandi 10 < 1 0 Salicornia agg. 8 < 1 Carex serotina 15 < 1 0 Description: Open Scir us cover with frequent Phra mites shootsover salt tolerant community with occasional Juncus maritimus tussocks. Eleocharis and A rostispatchy and 0 locally dominant among otherwise sparse understore species on poached substrate.30m. 0

0

0 21 0 Lissagriffin Lake

Site: Lissa riffin Lake Transect code: D Location: Marginal swam Sample oint: 4 Marginal Sample area: 16m2 4x4 Substrate: Peat Depth: 0 cm Salinit : ----- NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - Agrostis stolonifera sub-community Height cm Cover Total Plant 90

Schoeno lectus lacustris ss tabernaemontani 100 75 Phra mites australis 80 5 Scir us maritimus 80 5 Eleocharisalustris 20 5 A rostis stolonifera 15 5 Glaux maritima 10 < 1 Samolus valerandi 10 < 1 Oenanthe lachenalii 20 < 1

Description: Fairly dense Schoeno lectus with sparse Scir us maritimusand Phra mites shoots. Patch Eleocharis and A rostis dominant among species-poor understoreof sparse salt tolerant species. 20m.

J

22 u

Lissagriffin Lake 0

Site: Lissa riffin Lake Transect code: D 0 Location: Marginal swam Sample oint:5 Marginal Sample area: 16m2 4x4 Substrate: Peat 0 Depth: 0 cm Salinit : ----- NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - sub-community undetermined 0 Height cm Cover %) Total Plant 50 0 Schoeno lectus lacustris sstabernaemontani 100 30 A rostis stolonifera 15 5 Pedicularisalustris 30 5 0 H drocot le vul aris 4 5 A ium nodiflorum 10 < 5 0 Mentha a uatica 15 < 5 Ranunculus flammula 15 < 1 Samolus valerandi 8 < 1 0 Tri lochinalustris 10 < 1 Baldellia ranunculoides 15 < 1 Ana allis tenella 2 < 1 0 Juncus articulatus 25 < 1 Carex ni ra 15 < 1 Description: Open cover of Schoeno lectus with A rostis stoloniferalocally dominant 0 amongst open round cover of freshwater species on heavily poachedsubstrate. 50m. Backing freshwater Phra mites fen. c.20m. 0 Backing pasture on risinground.

0

0

0

0

0

0

0

0 23 0 J

Lissagriffin Lake J

4.3.4Evaluation

`Not Valuable'

This is a shallow sandy lagoon. Salinity was 0-20 partsper thousand at time of survey over the site as a whole, 0-6 parts per thousandwithin the eastern section landward of the causeway. The whole eastern section and most of thewestern section were surveyed by means of wading.

Ruppia is the only aquatic higher plant. It is confinedto the southern half of the eastern section and occurs at a sparse to patchy cover.It is low-growing here.It was not possible to identify this Ruppia to species.

J Ulva lactuca and a Fucus species are occasional in thewestern section of the site, where no higher plant species occur.

Marginal communities are fairly diverse. Phragmites is extensive around the freshwater inflows at the eastern end and fringes the northeastern shore. Scirpus maritimus and Schoenoplectus lacustris ssp. tabernaemontani occur in single species swamps along south eastern shores and with saltmarsh species alongsouthern shores. Puccinellia maritima dominated saltmarsh occurs at the western end oneither side of the mouth of the outlet channel.

Lissagriffin Lake is a very species-poor site with no speciesor communities of notable interest.

Further survey is not recommended.

J

7 LA

24 Lissagriffin Lake J

4.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork.

4.4.1 Site Description 7 J Coastal brackish lake in two sections (Plate 1) divided bycauseway bridge (3 outflow/inflow c. 0.7m open pipes) with inlet channel through sand dunes,sea apparently entering only at high J tide. Much of upper and lower lake shores with mostlyanaerobic sand-flat margins, covered at high spring tides and probably during winter. Marginal vegetation dominatedby Phragmites communes, Scirpus maritimus and Schoenoplectus lacustris, grading into dune pasture(lower 1 channel and lake), and marshy pasture (upper lake). Salinity higherin lower lake (above and below causeway, 30 viii 1996: 27%o and 32%0, respectively). Marginsgrazed by cattle, with moderate soil poaching in occasional patches.

Subsites (Fig.4.4.1)

1. Marshy pasture (V 772262) Marshy pasture with Agrostis, Juncus, carices, etc. near Schoenoplectus anddense Phragmites stands, grazed by cattle, and flooded during winter at least.

2. Phragmites l grass (V 772265) J Sparse Phragmites commnis in grass c. lm from dense Phragmitesbeds on lake margin. 3. Bridge sandy margin (V 772263) Silty sand with bridge cobble stones below causeway, covered athigh spring tide.

4. Scirpus maritimus (V 774263) Sparse Scirpus maritimus with Schoenoplectus lacustris and Glaux maritinia onpartially aerobic sandflat, flooded at high spring tide and during winter.Vegetation cover from c.20- 80%.

4. Sandflat (V 766260) Sandflat aerobic, covered at high spring tide, in broad tidalchannel.

4.4.2 Methods Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

25 0

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0

0

0

0

0

G

0

a

0

loom 0

0

0

0

Fig. 4.4.1. Map of sampling sites (Carabidae and Staphylinidae) atLissagriffin Lake, Co. Cork 0 1 - Pitfall traps 2 - Ground search 3 - Pitfall traps, S-vac 4 - Cobble search 0 5 - Flotation 0

0

0 J

Lissagriffin Lake

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites. J Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for J instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncos gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 4.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as

26 0

Lissagriffin Lake 0

'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample 0 were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was 0 effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were 0 fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 0

TABLE 4.4.1. Details of sampling methods. 0

0 Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels; collars used where cattle/horses occur a Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth 0 burrow casts observed; agitated soil floated in water 0 Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer 0 substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 0 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated C with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent. 0 Variety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by 0 27 0 J

Lissagriffin Lake

other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare J sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a J result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks. J Quality control: identification J Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv. :Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna - a definition proposed for use in sitesurveys. Bull. Ir. biogeog. Soc. 14: 48-53.

28 u

Lissagrilfin Lake 0

Methods used at this site 0 Carabidae and Staphylinidae (Coleoptera) were recorded from : Marshy pasture - S-vac suction sampler (30 viii 1996), c.2 m2; 0 Marshy pasture - 6 plastic pitfall traps with funnels andethylene glycol preservative (30 viii - 3 x 1996); Phragmites /grass - 6 pitfall traps (30 viii- 3 x 1996); 0 Bridge sandy margin - cobble search (n=30, 13 vii 1996); Scirpus maritimus area- 1 h ground search (13 vii 1996); Sandflat - flotation from incoming spring tide (30 viii 1996). 0

Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they 0 are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. 0 4.4.3Survey Results

Five species of carabid and seventeen species of staphylinid wererecorded, one of which is 0 regarded as an indicator species (Table 4.4.2). 0 Carabus clathratus is a stenotopic species occurring in dense vegetationon peat soils, from bogs, lake shores and also salt-meadows (Koch 1989, Hyman andParsons 1992). It occurs across the Palaeartic (Freude 1976), but is very local inGreat Britain (Hyman and Parsons 0 1992), and appears the be local in Ireland. The singleindividual was recorded from the marshy meadow, but probably orginated in the nearby reedbeds. 0 The staphylinid assemblage recorded from the marshy meadow was lowin diversity, with most species being eurytopic or tolerant of disturbance (Table 4.4.3). 0

0 TABLE 4.4.2Carabidae and Staphylinidae (Coleoptera) recorded from Lissagriffin Lake. Nomenclature follows Lucht (1987) and Lohse and Lucht (1989), withthe exception of Diglotta which follows Good (in preparation), and Tachyporus 0 which follow Booth (1988). 0 Species No. individuals

Carabidae 0

Agonum marginatum (L) 1 Agonum pelidnum (Payk.) I 0 Amara ovata (F.) 1

Carabus clathratus L. 1 Indicator species

Pterostichus niger (Schall.) 1 0

a 29 0 J

Lissagriffin Lake

Staphylinidae

Atheta amplicollis (Muls. Rey) 8 Atheta elongatula (Grav.)3 Atheta graminicola (Grav.) 8 Atheta vestita (Grav.) 2 Bledius subniger Schneid. 18 Carpelimus corticinus (Grav.) 1 Diglotta mersa (Hal.) 4 Drusilla canaliculata (F.) 141 Gabrius pennatus Sharp 3 Lathrobium quadratum (Payk.) 2 Othius laeviusculus Steph. 1 Philonthus addendus Sharp 1 Quedius nigriceps Kr. 1 Stenus bimaculatus Gyll. 1 Stenus boops Ljungh 15 Tachinus signatus Grav. 1 Tachyporus dispar (Payk.) 1

TABLE 4.4.3. Staphylinid assemblage from lake margin marshy pasture, Lissagriffin Lake (suction sample and pitfall traps combined).

Abund. Cat. Species No. Main biotope

Dominant Stenus boops 15 Eurytopic, incl. marshy meadows

J Intermediate Atheta amplicollis 4 Eurytopic, incl. disturbed soil Atheta graminicola 2 Eurytopic, incl. marshy meadows Gabrius pennatus 3 Eurytopic, incl. disturbed soil Lathrobium quadratum 2 Marshes, and muddy shores

Present Carpelimus corticinus 1 Eurytopic, including marshy shores Tachyporus dispar 1 Eurytopic, esp. grassland

4.4.4 Evaluation

Of low conservation interest for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

J Scientific Argument for Rating Only one wetland indicator species was recorded. The staphylinid assemblagerecorded from the marginal marshy pasture indicated disturbed conditions, probably due tosaline water flooding. However, further investigation of the reedbed marshes associated withthis site may discover more freshwater wetland indicator species.

30 v

Lissagriffin Lake 0

4.4.5References 0

Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation 0 of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Hyman, P. S. and Parsons, M.S. (1992) A review ofthe scarce and theatened Coleoptera of Great Britain. Part 1. UK Nature Conservation Series No. 3,Joint Committee for 0 Nature Conservation, Peterborough. Freude, H. (1976) Fam. Carabidae. In: Freude, H., Harde, K.W.and Lohse, G.A. (eds). Die KdferMitteleuropas. 2. Goecke & Evers, Krefeld. 0 Koch, K. (1989) Die KdferMitteleuropas. Okologie. 1. Goecke & Evers,Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die KdferMitteleuropas. 12. 1.Supplementband mit Katalogteil. Goecke & Evers, Krefeld. [I Lucht, W.H. (1987) Die KdferMitteleuropas. Katalog. Goecke & Evers, Krefeld. 0

0

0

0

a

a

0

0

0

0

0

0

0

31 J

Lissagriffin Lake

4.5 SUMMARY AND EVALUATION

Lissagriffin Lake is a relatively small (12 ha) shallow, artificialsaline lake at least partly created by construction of a causeway at the headof a tidal inlet. Ornithologically the area is great interest for its wintering wadersand wildfowl, and for attracting rare American vagrants. The lake lies within a proposed NHA (Site Code No.1040). The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology Low Aquatic Fauna Low 7 Vegetation Low J Ecotonal Coleoptera Low

Geomorphology Lissagriffin Lake is not a coastal lagoon, but a relativelysmall ( 12 ha), shallow, saline lake lying at the head of a long sinuous tidalinlet. A natural lake may have existed in the past, but the presence of permanent water is atleast partly due to the construction of a causeway which restricts water flows in both directions. Although the lake and tidal inlet running through coastal dunesare geomorphologically very interesting, as a lagoon or saline lake it isrelatively small and largely artificial. Based on geomorphology, the lake is therefore rated as oflow conservation value

Aquatic Fauna

A total of 24 taxa were identified which included onlytwo lagoonal specialists. (Sigara stagnalis and Palaemonetes varians). The recorded fauna typifies a brackishwater of medium to highsalinity with open access to the sea. The poor representation of oligohaline species,even at the stations furthest from the sea, may be due to poor growthof submerged macrophytes caused by overheating in shallow water and possibly tidal scouring. However,the frequency of ragworms throughout the lake suggests that the lake bed isnot exposed or overheated for long periods. When the presence of a sea inletis taken into account, the lake may be described as poor in species None of the recorded species can be described as rarein Ireland and the aquatic fauna is relatively poor and of little interest. In conclusion, based on the aquatic fauna, Lissagriffin is oflow conservation value.

32 Lissagriitin Lake 0

Vegetation 0

Ruppia was the only aquatic higher plant recorded. It isconfined to the southern half of the eastern section and occurs at a sparse topatchy cover. It is low-growing here. 0 It was not possible to identify this Ruppia to species.Ulva lactuca and a Fucus species are occasional in the western section of the site, whereno higher plant species occur. 0 Marginal communities are fairly diverse. Phragmites is extensive around the freshwater inflows at the eastern end and fringes the northeastern shore. Scirpus 0 maritimus and Schoenoplectus lacustris ssp. tabernaemontani occur in single species swamps along south eastern shores and with saltmarsh species alongsouthern shores. Puccinellia maritima dominated saltmarsh occurs at the western end oneither side of 0 the mouth of the outlet channel.

Lissagriffin Lake is a very species-poor site with no speciesor communities of notable 0 interest and is regarded as of low conservation value

Further survey is not recommended. 0

Ecotonal Coleoptera 0 Five species of carabid and seventeen species of staphylinid wererecorded, one of which is regarded as an indicator species a Carabus clathratus is a stenotopic species occurring in dense vegetationon peat soils, from bogs, lake shores and also salt-meadows. It occurs across thePalaeartic but is very local in 0 Great Britain and appears the be local in Ireland. Thesingle individual was recorded from the marshy meadow, but probably orginated in the nearby reedbeds. 0 The staphylinid assemblage recorded from the marginal marshy pasture indicated disturbed conditions, probably due to saline water flooding. However, further investigation of the reedbed marshes associated with this site maydiscover more 0 freshwater wetland indicator species. As only one wetland indicator species was recorded Lissagriffin Lakeis regarded as of low 0 conservation interest for terrestrial ecotonal community

Summary 0

The lake and tidal inlet are of great scenic andornithological interest. However, based on all four criteria used in the survey LissagrifTnis rated as of low 0 conservation value. as a coastal lagoon or saline lake andproposal as an SAC is not recommended. 0

0

0 33 0 J J J COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

5. FARRANAMANAGH LAKE

7

Brenda Healy Geoff Oliver Pat Hatch J Jervis Good

February 1997

J

Prepared for the National Parks and Wildlife Service

(BioMar/Life) 5. FARRANAMANAGH LAKE

CONTENTS

5.1 Study Area

5.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

5.2.1Methods 5.2.2Results 5.2.3Discussion 5.2.4Threats 5.2.5Evaluation 5.2.6References

5.3 Vegetation Survey (Pat Hatch)

5.3.1Site Description 5.3.2Methods 5.3.3Results Shore based survey i Transect tables 5.3.4Evaluation

5.4 Ecotonal Coleoptera i (Jervis Good) 5.4.1 Site description 5.4.2Methods 5.4.3Results 5.4.4Evaluation 5.4.5 References

5.5 Summary and Evaluation Farranamanagh Lake

J 5. FARRANAMANAGH LAKE, Co. Cork. OS Grid Reference: V 830 378, 1:50,000 Sheet No. 88 J Alternative names:

5.1 STUDY AREA

Generalfeatures J Farranamanagh Lake is situated in Dunmanus Bay on the southside of the Sheep's Head peninsula, 3 km east ofKilcrohane (Fig. 5. 1. 1).The lake is a small, completely natural lagoon lying behind a cobble barrier through which runsa permanent outlet. Small freshwater streams enter the lagoon in the north. Onspring tides, seawater enters through the inlet and overtops the barrier during storms.Very little is known about the lake except that Whooper swans (Cygnus cygnus) arerecorded in the winter.

Climate and oceanographic influences J (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) J The region experiences a mild oceanic climate with a smallannual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 6.5-7°C in January and15.5 °C in July. The growing season (the period of mean daily air temperatures above 6°C) is 11 months and as snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1300 mm, and the number of raindays (1 mm or more) is about 200. Winds are mainly from the south and southwest.Mean annual hourly wind speeds are between 5 and 6 m/s and a maximumwind speed of 49-50 m/s is estimated J to occur once in 50 years. The daily duration ofbright sunshine averages 3.5-4.0 hours. Mean relative humidity is around 85% as on allIrish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 m (Carter 1992).Maximum wave heights (averaging once in 50 years) are 25-30 (Couper1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS) in the Kenmare Riveris 4.0 in (Admiralty Tide Tables). Sea temperatures are lowest in February and highestin August. Landscape and Geology Bedrock is Old Red Sandstone and soils are generally acidic and mostly peaty podzols and acid brown earths (RoyalIrish Academy, 1979). Land surrounding the lake is a mixture of rocky hillside,small peat bogs, wet heath and small irregular fields of pastureland.

Lake Topography The lake is roughly 300 in from north to south,300 m across at its widest point and covers approximately 5 ha. The lakeis about 2 in at its deepest

n 1 u 0

0

rJ

rJ

rJ

0

rJ

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0

Dunrnanus west ma( a6 Tram a

0 Fig. 5. 1.1Section of 1:50 000 map showing locality of Farranamanagh Lake

0 J Farranamanagh Lake

point and most of the bed of the lake iscomposed of cobbles and gravel, with sand, peat and organic silt in sheltered areas.

Hydrology Small streams enter the lake from the north and seawaterenters on spring tides. During storms, at high tide, waves breakover the shingle bar but entry of seawater by overtopping has increased due to gravel abstraction duringthe 1980's (P. Whelan pers. comm.). No tidal variation in water level ofthe lake was apparent during the study period, but winter water levels can be 1m higher than summer.

Salinity and water quality Seawater at approximately 34%o enters the lakeon spring tides and by overtopping the barrier during storms butthe lake is small and the volume of freshwater entering the lake is probably sufficient toensure low salinities throughout the year. The only major source of nutrients tothe lake is agricultural. The amount is likely to be low in this area andregular flushing by seawater is likely to prevent any serious eutrophication problems.

J 2

1 J Farranamanagh Lake

5.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver, Dept. of Zoology, University College Dublin

5.2.1Methods

Environmental variables Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined usinga GPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and J salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o. precision). A photographic record was made of the site andlocal information sought concerning background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations B and C inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the surveyare affected by many environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, buteven these are affected by

3 u

Farranamanagh Lake 0 inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are 0 purely subjective, and absolute numbers vary between taxa. Standard keys were used to identify specimens, but larval orjuvenile stages were difficult to identify with certainty. Some groups require adult malesfor identification 0 and these were often not available due to low populationdensity and the limited number of individuals collected in the time available (e.g. Jaera,hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify when preserved IJ (turbellarians, leeches). All Diptera are identified to family level. 0

5.2.2Results 0 Farranamanagh Lake was sampled on 5.vii.96 during the first partof the survey, and from 17-18.vii.96 during the more intensive survey. 0 Four sampling stations were selected in the lake to reflectthe influences of substrate, freshwater and tidal inflows. Positions of the sampling stationsare shown in Fig.5.2.1. 0 Environmental Variables

Station A (OS 8297 3774) was located at the westernend of the lake, close to the IJ barrier (Plate. 5.2. 1). Substrate consisted of cobbles and gravelclose to the barrier with peat and organic silts in deeper water. Water depthvaried from 0- 1 m and salinity measured 2-3 %o. 0 Station B (OS 8312 3784) was located at the northernend of the lake where the main freshwater stream enters the lake(Plate 5.2.2). Substrate consisted of sandand silt with 0 large boulders, water depth varied from 25- 60 cm and salinity measured 1 %o. Station C (8307 3765)was located at the southern end ofthe lake near the outlet (Plate 5.2. 1). Substrate consisted of cobbles, gravel and sand,water depth was 1 - 1.5 0 m and salinity measured 6%0. Station D: (OS 8301 3770) was located along the western shore between stations A lJ and B (Plate 5.2. 1).Substrate consisted of cobbles and gravel, water depth varied from 0-25 cm and salinity measured 5%0.. IJ Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 5.2.1. Among 17 taxa listed, 16 are identified tospecies. One species is poly- IJ mesohaline, 10 are euryhaline, and one is oligo-mesohaline and 2are limnic; no marine species were recorded (Fig. 5.2.2). One of the species islisted as a lagoonal specialist 0 in Britain (Davidson et al. 1991). The fauna was poor at all stations and only Neomysisinteger, Palaemonetes varians and Gasterosteus aculeatus were common. Jaera nordmanni and gammarid C amphipods were confined to D where there were cobbles inshallow water, and Carcinus maenas was only taken at C which was nearto the sea inlet. Most other species were widely distributed in the lake. 0

0 4 J

Kilcrohane 3 km

J 380

r

379

378

377

coastal footpath 375

374 I I I I I I 1 828 829, 830 831 832 833 ,-,./rock' f

Fig. 5.2.1.Location Map of Sampling Stations in Farranamanagh Lake, CoCork U

Table 5.2.1. Fauna Recorded at Farranamanagh Lake, Co. Cork. Julyand August, 1996. () = recorded in July 0

Fauna Sampling Stations (L.T. =light trap) -- - - A L.T.A B ! L.T.Q C L.T C-- -1) 0 Ponfera------F TC------i ------Cnidana !Aurelia aurita ! (+) Turbellaria 0 I _--_------1-----._ Nemertea --j -1 I ------Annelida j j - - Crustacea 0 - - +- ---! ------Ostracodal ; ------i --- I Cirnpedia1 1 ----- 15 0 Mysidacea Neomysis integer 0 10 n T-- fsopoda Jaera nordtnanni _ . + Ligia oceanica + 0 Amphipoda + + a 25 + + Allomelita pellucida + _ + Gammarus duebeni j - G. zaddachi + a + + -- 0 Tanaidacea _ Decapoda Carcinus maenas F F. c 0 Crangon crangon ; 2 i _

I Palaemonetes varians J a 60 c 16 a 31

Arachnids ( I i _ ri Insects Thvsanura ------Ephemeroptera 0 Odonata Plecoptera Trichoptera 0 Hemipterai ~ __-- Coleopteral Anacaena globulus - i + j - I Haliplus lineatocollis I ! + 0

Diptera; Chironomidac + + Molluscs ri Prosobranchia Pntamopyrgus anzipodarum + + + + + Opisthobranchia Pulmonatai 0 Bivalvial B ryozoa Echinodermata 0 Tunicata - _7 7 Tcleostci Anguilla anguilla F -

Gusterosteus aculeams 2 -15 + + I omatoschistus nucrops 3 +- , + + 0

0

+ = present; o = occasional; c = common; a= abundant; F = fyke net; 0

0 J Farranamanagh Lake 7

Table 5.2.2 Ecological categories of the recorded taxa in FarranamanaghLake (excluding marginal species). L = lagoonal specialist according to Davidsonet al. (1991).

J Marine None

Poly-mesohaline Crangon crangon

Euryhaline Neomysis integer Jaera nordmanni Gammarus duebeni Gammarus zaddachi Allomelita pellucida* Palaemonetes varians L 7 Carcinus maenas Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps iz Oligo-mesohaline Potamopyrgus antipodarum

J Limnic Anacaena globulus Haliplus lineatocollis

iz *The salinity range of this species is not known

5.2.3Discussion

Faunal diversity was poor and no species was present athigh density. The faunal assemblage typifies a brackish lagoon with a sea inlet, butwhere the freshwater inflow is sufficient to counteract the marine influence and the salinityremains generally low. The salinities recorded at the time of sampling (2-6%o) maybe typical but there are probably wide and rapid fluctuations according to tides and weather.The poor representation of oligohaline species may be due to temporary highsalt levels which prevent populations becoming established. This seems to be the onlypossible explanation for the absence of corixids and the scarcity ofbeetles in areas where there was good growth of Ruppia. None of the species recorded can be described as rarein Ireland

7 5.2.4Threats J

ri There are no apparent threats to the lake. A bridgehas been constructed as part of the v coastal path but this does not appear to affect thelake although it may attract more visitors. Removal of shingle from the landward side of the barrierduring the 1980s increased the frequency of overtopping (P.Whelan pers. comm.) but this practice appears to have been discontinued.

5 1 J Farranamanagh Lake

J 5.2.6References and Additional Sources of Information

Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic DepartmentAdmiralty. 1995. Admiralty Tide Tables: European waters including the Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation Mediterranean appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. J Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vo 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. PhD Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp- J Sheppard, R. 1993 Irelands Wetland Wealth. Irish Wildbird Conservancy, 152pp. J J J

7

7

7 1 Flats .1'2:1 'viewStations of the s®nthwestemA (distance), D (middle area of FatT natnanagh Like looking distance) and C (foreground), west, pinto 5-:12 View of the nort gem area of Fati4ana natiagh Lake looking west; Station B 0cf04 J

Farranamanagh Lake

5.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a way as to J facilitate its subsequent assessment and consideration for legal protection.

5.3.1Site Description(Fig. 5.3. 1)

This small lagoon is bordered by fairly low-lying pasture tothe west and north west and heath and bog vegetation on higher ground to theeast and north east. The shingle barrier lies to the south, through which the outlet tothe sea runs from the southern tip of the lake.

The only freshwater stream flows in at the head ofthe northern bay. Fen vegetation occurs here with open willow carr. Marginal swamp is foundhere and as a fringing strip along the west and north western shores.It also occurs in small isolated patches along the rockier eastern shore where the low peat cliffsof the north eastern quarter J give way to outcropping bedrock to the south.

A coastal footpath runs along the barrier, crossing the outletchannel via a stone bridge.

5.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects J 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 5.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

8 r'l U I U

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High WaterNlark s »tdYl5la a

0

L 0

Fig. 5.3.1 0

0 N

J

K7-kVdferMark

J

Fig. 5.3 Farranamanagh Lake, Co.Cork: Location of Transects and Shore-based Survey Sections u

Farranamanagh Lake 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a c species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was 0 generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. G Representative examples of every marginal community encountered during thecourse of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 0

9 76-90 % . 8 51-75 % 7 34-50 % 6 26-33 % 5 11-25 % 4 4-10 % 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals 0

0 9 Farranamanagh Lake

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100% IV 61-80 % III 41-60 % II 21-40 % J I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

J Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences:

10 u

Farranamanagh Lake 0

a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications 0

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway a

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of G charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, thepresence of rare species and whether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection. 0

0

11 Farranamanagh Lake

A `Potentially Valuable 'site is one which this survey indicatesmay be of interest and which may prove to be valuable following further survey.

A `Not Valuable' site is one that is shown tobe of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

J 5.3.3Results

1. Shore-based survey

Section A-B (Transect A)

Aquatic: Ruppia sp. - sparse Filamentous algae - patchy

Coarse sand and gravel substrate with frequent cobbles

Marginal:Single species Scirpus maritimus and Schoenoplectus lacustris ssp tabernaemontani swamps. 2-3m

Adjacent:Festuca rubra - Potentilla anserina dominated grassland J Section B-C

J Aquatic: Unchanged

Marginal:30-40cm earth cliff J Adjacent:Unchanged

Section C-D

Aquatic: Unchanged

Marginal:Swamp vegetation as A-B

Adjacent:Unchanged

Section D-E

Aquatic: Filamentous algae - extensive Enteromorpha - sparse

Marginal:As B-C

Adjacent:Unchanged

12 Farranamanagh Lake 0

Section E-F 0 Aquatic: Ruppia sp. - fairly extensive to at least 4m out Filamentous algae- extensive Enteromorpha - sparse 0

Marginal:Unchanged 0 Adjacent:Unchanged ------0 Section F-G

Aquatic: Unchanged 0

Marginal:Emergent Juncus maritimus forming I m strip along shore 0 Adjacent:Heath vegetation dominated by Ulex europaeus and Pteridium aquilinum ------Section G-H 0

Aquatic: Ruppia sp. - sparse to at least lm out Filamentous algae- sparse 0

Gravel substrate with frequent cobbles 0 Marginal:Scirpus maritimus and Schoenoplectus lacustris ssp tabernaemontani swamp with each species locally dominant. 2-3m 0 Grading to Im strip of dense Juncus gerardii and Agrostisstolonifera

Adjacent:Unchanged 0 ------Section H-I

Aquatic: Filamentous alge- sparse

Marginal:30-50cm earth cliff 0

Adjacent:Festuca rubra- Potentilla anserina dominated grassland ------0 Section I-J

Aquatic: Ruppia sp.- fairly extensive open cover to at least 2m out Filamentous algae- patchy cover

Marginal: Schoenoplectus swamp with occasional Scirpus shoots and sparse Ruppia. 2-10m

Adjacent: 1.5m dry stone wall 0 Backing to Lolium perenne grassland 0

13 J

Farranamanagh Lake

Section J-K (Transect B)

Aquatic: Ruppia sp. - fairly extensive open cover to at least2m out Filamentous algae - extensive J Silt and gravel substrate with frequent cobbles

Marginal:Open single species Schoenoplectus swamp with sparse Ruppia and patchy filamentous algae. 5-8m Backing to 50cm earth cliff

Adjacent:Heath vegetation dominated by Pteridium aquilinum

Section K-L ri Aquatic: Unchanged LJ Marginal:Unchanged

Adjacent:1.5m dry stone wall Lolium perenne - Holcus lanatus - Cynosaurus cristatus pasture

Section L-M

Aquatic: Ruppia sp.- sparse to at least 2m out Filamentous algae - patchy cover

Cobble and boulder substrate

Marginal: Single species Scirpus maritimus swamp with sparse Ruppia. 3m

Adjacent:Unchanged

Section M-N

Aquatic: Ruppia sp. - sparse to at least 2m out Filamentous algae - patchy

Silt and gravel substrate with frequent cobbles

Marginal: Schoenoplectus swamp as J-L J Adjacent:Unchanged ------

14 u

Farranamanagh Lake 0 Section N-O (Transect Q 0 Aquatic: Unchanged

Silt substrate 0

Marginal: Single species Schoenoplectus swamp with sparse Ruppia. 25-40m Backing to 30-50cm earth cliff 0

Adjacent:Molinia caerulea dominant amongst fen vegetation bordering freshwater inflow. 0 Frequent Lythrum salicaria, Mentha aquatica, Menyanthes trifoliata, Filipendula ulmaria. Occasional Salix cinerea ------0 Section O-P 0 Aquatic: Ruppia sp. - very sparse to at least 2m out Filamentous algae- extensive 0 Gravel substrate with frequent cobbles and boulders

Marginal:50cm earth cliff 0

Adjacent:Heath vegetation dominated by Ulex gallii and Pteridium aquilinum ------0 Section P-O

Aquatic: Unchanged 0

Marginal:Small single species swamps of Scirpus maritimus (2x 1 m),Eleocharis palustris (12xlm) and Schoenoplectus lacustris ssp tabernaemontani 0 (5x3m)

Adjacent:Heath as O-P and bog vegetation dominated by Molinia caerulea, 0 Trichophorum cespitosum and Sphagnum spp. ------0 Section Q-R

Aquatic: Unchanged 0 Marginal:Bedrock shore with occasional small Schoenoplectus swamps- average area c. 15m2 - backing to short stretches 50cm earth cliff

Adjacent:Unchanged ------0

0

0 15 Farranamanagh Lake

Section R-S

Aquatic: Unchanged

Marginal:Scirpus maritimus - Schoenoplectus swamp with each species locally dominant. 1-6m Grading to Juncus gerardii - Festuca rubra - Agrostis stolonifera community with sparse Cochlearia anglica and occasional Juncus maritimus tussocks. 15m

Adjacent:Festuca rubra - Potentilla anserina grassland ------

2. Transects

Site: Farranamana h Lake Transect code: A Location: Outlet to sea Sample point:1 Aquatic - 2m out Sample area: 16m2 4x4 Substrate: Sand,ravel, cobbles J Depth: 20 - 50 cm Salinit :25arts per thousand NVC communit :----- Height cm Cover Total Plant 25 Higher Plant 15

Ruis s p. 15 15

Algae 10

Filamentous algae 10

Description: Open cover of Ruis with occasional patches of filamentous algae.

J

J

16 Farranamanagh Lake 0

Site: Farranamana h Lake Transect code: A Location: Outlet to sea Sample point: 2 Marginal 0 Sample area: lOm2 10x1 Substrate: Sand,ravel

Depth- 20 cm Salinit : 20 arts per thousand NVC communit :S21 Scius maritimus swam - Scir us maritimus sub-community 0 Height cm Cover Total Plant 80 0

Scius maritimus 70 80 0

Description: Fairly dense single species Scius maritimus swamp. lm. 0

Site: Farranamana h Lake Transect code: A 0 Location: Outlet to sea Sample oint: 3 Marginal Sample area: 10m2 10x1 Substrate: Silt

Depth: 0 - 20 cm Salinit : 20 arts per thousand NVC communit :S21 Scius maritimus swam - A rostis stolonifera sub-community Height cm Cover Total Plant 90

Scius maritimus 70 75 0 A rostis stolonifera 25 20 a Descri tion: Fairly open Scius swam with patchy A rostis cover. 2m. Grading to Festuca rubra- Potentilla grassland (barrier). 0

0

0

0

0

0

17

E Farranamanagh Lake

Site: Farranamana h Lake Transect code: B Location: Marginal swam Sample point:1 Aquatic - 2m out Sample area: 16m2 4x4 Substrate: Coarse sand,ravel, cobbles

Depth: 50 cm Salinit : 16arts per thousand

NVC communit : ----- Height cm Cover Total Plant 100 Hi her Plant 20

Ruis s p. 25 20

Algae 90

Filamentous algae 90

Description: Filamentous algae dominant with open Ruis cover.

Site: Farranamana h Lake Transect code: B Location: Marginal swam Sample point: 2 Marginal Sample area: 40m2 10x4 Substrate:Silt, cobbles

Depth: 30 - 50 cm Salinit : 15arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - S.lacustrisssp tabernaernontani sub-community Hei ht cm Cover Total Plant 80 Hi her Plant 60

Schoeno lectus lacustris ss tabernaemontani 100 60 Ruis s p. 15 < 1 J Algae 25

Filamentous algae 25

Descri tion: Open Schoeno lectus swam with sparse low growingRuis and patchy cover of free-floating filamentous algae. 4m. J

18 u

Farranamanagh Lake 0

Site: Farranamana h Lake Transect code: B Location: Marginal swam Sample oint: 3 Marginal - pool 0 Sample area: 20m2 10x2 - whole stand Substrate: Silt

Depth: 30 cm Salinit : 16arts per thousand NVC communit :----- 0 Height cm Cover Total Plant 30 0 Hi her Plant 30

Ruis s p. 20 30

Algae < 1

Filamentous algae < 1

Description: Open cover of low growing Ruis with sparse free-floating algae.

Site: Farranamana h Lake Transect code: B Location: Marginal swam Sample oint: 4 Marginal Sample area: 20m2 10x2 Substrate: Silt

Depth: 20 - 30 cm Salinit : 16arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp tabernaernontani sub-community 0 Height cm Cover Total Plant 75 Hi her Plant 70 0

Schoeno lectus lacustris sstabernaemontani 100 70 Ruis s p. 15 < 1 0

Algae 5 0

Filamentous algae 5 0 Description: Fairly open Schoeno lectus swam with sparse low growingRuis and free- floating filamentous algae. 2m Backing 50cm earth cliff. Backing Pteridium a uilinum dominated heath.

0

0 19 0 J

Farranamanagh Lake

Site: Farranamana h Lake Transect code: C J Location: Freshwater inflow Sample point: 1 Aquatic - 2m out Sample area: 16m2 4x4 Substrate: Silt J Depth: 50 cm Salinit : 16arts per thousand NVC communit :----- Height cm Cover Total Plant 10 Higher Plant 5

Ruis s p. 20 5

Algae 5

Filamentous algae 5

Description: Sparse Ruis and filamentous algae. Ruis low growing.

Site: Farranamana h Lough Transect code: C Location: Freshwater inflow Sample point: 2 Marginal J Sample area: 100m2 10x10 Substrate: Silt Depth: 40 cm Salinit : 9arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - S.lacustrisssp tabernaemontani sub-community Height cm Cover Total Plant 80

Schoeno lectus lacustris ss tabernaemontani 120 80 J Ruis s p. 15 < 1

Description: Fairly dense Schoeno lectus swam with s arse lowgrowing Ruia. 25m.

20 u

Farranamanagh Lake 0

0 Site: Farranamana h Lough Transect code: C Location: Freshwater inflow Sample point: 3 Marginal - pool 0 Sample area: 60m2 15x4 - whole stand Substrate: Silt

Depth: 30cm Salinit : 9arts per thousand NVC communit :----- 0 Height cm Cover Total Plant 20 0 Ruis s p. 15 20 0 Description: Extensive but open cover of low growing Ruis in single species stand. Backing 40cm earth cliff. 0 Backing fen vegetation bordering freshwater inflow. Molinia caerulea dominant with L hrum salicaria, Mentha a uatica, Men anthes trifoliata,Fili endula ulmaria, Angelica s lvestris, Ranunculus acris, M ricaale frequent. Occasional Salix cinerea, increasing 0 cover to landward. 0

5.3.4Evaluation

`Potentially Valuable' 0 This is a rocky site of fairly high salinity (16-25parts per thousand) at time of survey.

Ruppia was the only aquatic higher plant found during thissurvey. It is well distributed around the site, occuring within two metres of theshore at sparse to patchy cover in most areas. It was not possible to identifysamples to species. 0 A Fucus species is locally abundant in the mouth ofthe outlet channel.

Marginal vegetation shows no notable diversity. Schoenoplectus lacustris ssp 0 tabernaemontani single species swamps fringe the eastern and north easternshores and also occur at the freshwater inflow and in places alongthe southern shore. Scirpus maritimus swamp occurs along parts of the southern shore. Theeastern shore consists of exposed bedrock alternating with stretches of low earth cliff.Small Scirpus, Schoenoplectus and Eleocharis palustris swamps occur at one point here approximately half way along the shore.

This seems to be a very species-poor site, although itis possible that additional aquatic species are present in deeper parts of the lagoon morethan ten metres out from the shore. 0 Further survey is recommended.

0

21 G Farranamanagh Lake

5.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork.

5.4.1Site Description

Coastal brackish lake with shingle barrier and inlet channel (Plate1), with seawater incursion at high spring tide. Lake shore with shingle cobbles andcoarse sand behind barrier, covered at high spring tide, with grass topped c. 0.5 m highcliff. Small inlet flood area mainly Juncus maritimus and grass dominated vegetation.

Subsites (Fig.5.4.1)

1. Juncus maritimus/ grass (V 831376) c. 100 m2 area of Juncus maritimus, grass, Potentilla anserina,etc. on sandy shingle soil with upper organic layer, near inlet, flooded in winter, water-table closeto surface during high spring tides. Near-shore water salinity 4%0 on 28 viii 1996.

2. Lake/barrier margin (V 830376) Cobble shingle on coarse sand to silt shore, covered atspring tides, with organic-rich silty- pebble cliffs to shingle/sand grassland.

3. Grass bank (V 829377) Grass bank with cliff to water with emergent Schoenoplectus lacustrisand Pteridium aquilinum etc., landward on interior not barrier shore, flooded duringhigh water

5.4.2Methods Site Rating using Indicator Species Species rarity or community typicality are the most frequently used criteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with n relatively undisturbed natural processes still operating. In particular, it isassumed that U this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, 7 washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these J processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

22 u

0

0

0

0

0

0

0 N 0

0

loom 0

0

D

0

Fig. 5.4.1Map of sampling sites (Carabidae and Staphylinidae) at Farranamanagh Lake,Co. Cork

I- Pitfall traps, S-vac 2 - Cobble search 3 - Pitfall traps 0

0

a

E J n j Farranamanagh Lake

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following 7 considerations were also taken into account: (1) Whether the indicatorspecies was Lj likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ J significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 5.4.1. Foreach site, a RHO BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were

23 u

Farranamanagh Lake 0

fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. G

n TABLE 5.4.1. Details of sampling methods. 0

Method Details No. replicates Sampling period, etc. a per unit sample 0 Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and 0 plastic funnels; collars used where cattle/horses occur Cobble samples Cobbles turned 0.5 - 2 in 30 0 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; 0 agitated soil floated in water Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during 0 warm weather without rain 0 Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. 0 Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are 0 representative of the sites, even if spring species may beabsent.

Variety of sampling techniques

Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. 0 That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site. 0

0 24 E J

Farranamanagh Lake

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for

.1 invertebrate fauna - a definition proposed for use in sitesurveys. Bull. Ir. biogeog. Soc. J 14: 48-53. Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : (1) Juncus maritimus/grass area - S-vac suction sampler (19 ix 1996),c. 2m2; (2) Juncus maritimus/grass area - 6 plastic pitfall traps with funnelsand ethylene glycol preservative (28 viii - 19 ix 1996), (3) Grass bank - 6 pitfall traps (28 viii - 19ix 1996); (4) Lake/barrier margin - cobbles search (2 x n=30, 12 vii1996).

25 u

Farranamanagh Lake 0

Species were selected as indicators of conservation value if: (1)they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they 0 are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. 0

5.4.3Results 0 Thirteen species of carabid and thirty-five species of staphylinid wererecorded, one species of which is regarded as an indicator species (Table 5.4.2). 0 There are three pevious Irish records of Stenus lustrator (Anderson1984), which appears to be local in Europe (Horion 1963). The species is tyrphophilous(associated with peat), but also occurs on marshy shores and flood meadows, according toKoch (1989). The Irish 0 records are from bogs (Anderson 1984), and the species wasalso recorded at Lough Aconeera and Drowngawn Lough in this survey, both of which possesspeat and bog margins.

TABLE 5.4.2 Carabidae and Staphylinidae (Coleoptera) recorded from Faranamanagh Lake. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), andBooth 0 (1988) for Tachyporus dispar. 0 Species No. individuals Carabidae a .4bax parallelipedus (Pill. Mitt) 4

Agonum gracile (Gyll.) 1 Agonum marginatum (L.) 1 a Agonum pelidnum (Payk.) 1

Anisodactylus binotatus (F.) 1 Bembidion mannerheimi Sahlb. 15 Dromius linearis (01.) 1 0 Dromius melanocephalus Dej. 2

Platynus albipes (F.) 1 Pterostichus niger (Schall.) 6 0 Pterostichus strenuus (Panz.) 1

Pterostichus vernalis (Panz.) 1 Trechus obtusus Er. 6 0 Staphylinidae

Amischa analis (Grav.) 1 Anotylus rugosus (F.) 14 Atheta amplicollis (Muls. Rey) 12 Atheta fungi (Grav.) 8

Calodera aethiops Grav. 1

Cordalia obscura (Grav.) 1 Dinaraea angustula (Gyll.) 4 Drusilla canaliculata (F.) 56 0

Encephalus complicans Steph. 1 Gabrius pennatus Sharp 2 Geostiba circellaris (Grav.) 1 0 Lathrobium brunnipes (F.) 2

Lesteva sicula Er. 1 0

26 J

Farranamanagh Lake

Metopsia retusa (Steph.) 1 Ocypus olens (Mull.) 1 Omalium excavatum Steph. 1 Oxypoda elongatula Aubd 2 Philonthus varians (Payk.) 1 Quedius nigriceps Kr. 1 Quedius schatzmayri Grid. 1 Quedius tristis (Grav.) 3 Rugilus erichsoni (Fauv.)5 Sepedophilus nigripennis (Steph.)9 Stenus bimaculatus Gy11.8 Stenus brunnipes Steph. 7 Stenus cicindeloides (Schall.) 1 Stenus clavicornis (Scup.) 2 Stenusfulvicornis Steph. 17 Stenus impressus Germ. 1 Stenus juno (Payk.) 19 * Stenus lustrator Er. 5 Indicator species Stenus ossium Steph. 2 Tachinus signatus Grav. 4 Tachyporus dispar (Payk.) 2 Xantholinus longiventris Heer 2

5.4.4Evaluation

Of no conservation interest for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional] J

Scientific Argument for Rating J The presence of one indicator species would indicate conservation interest,but a population of this species (Stenus lustrator) is probably not viable in thesmall area of flooded Juncus J maritimus, and the main population is likely to occur inthe nearby peaty soils with Sphagnum flushes.

5.4.5References

Anderson, R. (1984) Staphylinidae (Coleoptera) in Ireland - 3: Steninae.Jr. Nat. J. 21: 242- 251. Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Horion, A. (1963) Faunistik der Mitteleuropdischen Kdfer. IX. Staphylinidae: Micropeplinae bis Euaesthetinae. Feyel, Oberlingen-Bodensee. Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die KdferMitteleuropas. 12. 1.Supplementband mit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die KdferMitteleuropas. Katalog. Goecke & Evers, Krefeld.

27 I .J " " " U l a _ j LA l 11 u LA L_ 1 E l A " l 1 t " l i IL- A

Plate 1 Faranamanagh Lake and barrier, Co. Cork Ul COASTAL LAGOONS IN THE REPUBLIC OF IRELAND n u (VOLUME 111)

6. DRONGAWN LOUGH

U Brenda Healy n Geoff Oliver u Pat Hatch Jervis Good

February 1997

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Prepared for the National Parks and Wildlife Service

(BioMar/Life) J

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6. DRONGAWN LOUGH

CONTENTS

6.1 Study Area J 6.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

6.2.1Methods 6.2.2Results J 6.2.3Discussion 6.2.4Threats 6.2.5Evaluation J 6.2.6References

6.3 Vegetation Survey J (Pat Hatch)

6.3.1Site Description J 6.3.2Methods 6.3.3Results Shore based survey Transect tables 6.3.4Evaluation

6.4 Ecotonal Coleoptera (Jervis Good)

6.4.1 Site description 6.4.2Methods J 6.4.3Results 6.4.4Evaluation 6.4.5 References J 6.5 Summary and Evaluation

J

J rl Drongawn Lough J

J 6. DRONGAWN LOUGH, Co. Kerry.

OS Grid Reference: V 731640, 1:50,000 Sheet No. 84 Alternative names: ?

6.1 STUDY AREA

7 General features l_J Drongawn Lough is a natural saline lake with a restrictedtidal range due to a narrow connection with the sea through a small tidal bay whichitself has a narrow connection to the open sea. The lake lies on the southcoast of the Ring of Kerry peninsula, 6 km to the east of Sneem (Fig. 6.1.1). Kenmare Bay lies300 m to the south of the lake but is separated by a ridge of rock and the inletto the lake lies in the northeast corner via Coongar Harbour. Very little appears to be known about this lake, otherthan the fact that a small flock of Whooper swans (Cygnus cygnus ) is often present in thewinter. It is, however, a good example of a completely natural,moderately large,salinelake on the mountainous Kerry coastline in an almost perfect state of preservation.

Climate and oceanographic influences n (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of u Ireland 1979) The region experiences a mild oceanic climate with a smallannual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. 11 The mean daily air temperature is7°C in January and 15.5°C in July. The growing season (the period of mean daily air temperatures above 6°C is 11 months and as snow and frosts are rare, some plant growth is possible inwinter months. Annual rainfall is approximately 1400 mm, and the number of rain days (1mm or more) is 175-200. Prevailing winds are from the south and southwest. Mean annualhourly wind speeds are around 5.6 m/s and a maximum wind speed of49-50 m/s is estimated to occur once in 50 years. The daily duration of bright sunshineaverages 3.5-4.0 hours. Mean relative humidity is around 85% as on all Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce J large waves, inshore breakers commonly exceeding 8 m (Carter 1992).Maximum wave heights (averaging once in 50 years) are 25-30 m(Couper 1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS) in the Kenmare Riveris 4.0 m (Admiralty J Tide Tables). Sea temperatures are lowest in February and highestin August. Landscape and Geology The surrounding area consists largely of rock, moorland, 7 small peat bogs and scattered small fields of semi-improved pasture.Bedrock is Old Li Red Sandstone. Soils are generally acidic and consist mostly ofpeaty podzols and acid brown earths (Royal Irish Academy (1979). Land rises steeply fromthe coastline to mountains which run the length of the peninsula. The Macgillycuddy'sReeks and the highest peak in Ireland, Carrauntohil (1041 m) lie only 20km to the northeast.

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0 Fig. 6.1. I Section of 1 JO 000 map showing locality of DrongawnLough a

M Drongawn Lough J Lake Topography The lake may be glacial in origin. It is 700m from southwest to northeast, width varies from 50 to 300 m, area isapproximately 20 ha. The lake is very deep (up to 18 m) and most of the bedof the lake appears to be solid rock, or stoneof various sizes. In sheltered bays, especially in the southwest, thesubstrate consists rl J largely of unconsolidated peaty silt. Hydrology Precise details of hydrology are not known. Spring tides enterthrough the very narrow (approx. 3 m) inlet, but due tothe time lag and large volume of the lake, tidal fluctuations in water level are minimal. Only smallstreams enter the lake but n a relatively small seasonal fluctuation in water level presumably occursas a result of U increased rainfall during the winter and evaporation during summer. Salinity and water quality Seawater at approximately 34 %o enters through the narrows. Stratification undoubtedly occurs due to the depth of thelake, but was not investigated. Salinity of the lake is likely to remain closeto that of seawater, with a possible rise in summer due to evaporation and decrease inwinter due to dilution from direct rainfall and a limited amount of runoff from thesmall catchment area.

There are no major sources of pollutants to the lakeand water quality is presumably very high.

2 J Drongawn Lough

6.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver, Dept. of Zoology, University College Dublin

6.2.1Methods

Environmental variables Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation andin the morphometry of the barrier andinlets. Names and spellings J used are taken from the Discovery Series 1:50,000 O.S. mapand grid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1%0. precision). A photographic record was made of the site andlocal information sought J concerning background and recent history. Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations D and F inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16,12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of thespeciesinvolved.Itisthereforedifficultto make quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often witha different sampling method. The

J 3 U Drongawn Lough 0 Lake Topography The lake may be glacial in origin. It is 700in from southwest to northeast, width varies from 50 to 300 m, area isapproximately 20 ha. The lake is very deep (up to 18 rn) and most of the bedof the lake appears to be solid rock, or stoneof 0 various sizes. In sheltered bays, especially in the southwest, thesubstrate consists largely of unconsolidated peaty silt. 0 Hydrology Precise details of hydrology are not known. Spring tides enterthrough the very narrow (approx. 3 m) inlet, but due tothe time lag and large volume of the ri lake, tidal fluctuations in water level are minimal. Only smallstreams enter the lake but a relatively small seasonal fluctuation in water level presumably occursas a result of increased rainfall during the winter and evaporation duringsummer. 0 Salinity and water quality Seawater at approximately 34 %o enters through the narrows. Stratification undoubtedly occurs due to the depth of thelake, but was not 0 investigated. Salinity of the lake is likely to remain closeto that of seawater, with a possible rise in summer due to evaporation and decrease inwinter due to dilution from direct rainfall and a limited amount of runoff from thesmall catchment area. 0

There are no major sources of pollutants to the lakeand water quality is presumably very high. 0

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results of the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna andthe non-random distribution within the water column. Abundance categories ofpresent, common and abundant are purely subjective, and absolute numbersvary between taxa. J Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of thesewere larval or juvenile stages and difficulttoidentify with certainty. Some groups require adult males for identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (egJaera, hydrobiids). Finally, some soft-bodied groups were particularly difficultto identify when preserved (turbellarians, leeches).

6.2.2Results J Drongawn Lough was sampled on 5.vii.96 during the firstpart of the survey, and from 8-10.ix.96 during the more intensivesurvey. Eight sampling stations were selected in the laketo reflect the influences of substrate, freshwater and tidal inflows. Fig. 6.2.1 shows the position ofthese sampling stations in the lake.

Environmental Variables Station A (OS 7326 6428) was located at the northeastcorner of the lake in the area approaching the narrows (Plate 6.2.3). In thisarea water depth varied from 0 to 60 cm, substrate was small to medium sized cobbles with outcropsof bedrock and salinity J measured 32%0. Station B: (OS 7310 6414) was locatedon the shore of a small wooded island (Plate.6.2.3). Sampling was limited to the 0-1 m depth of the shoreline, substrate J consisted mostly of large rocks withsome coarse sand/gravel, salinity measured 30%0. Station C: was located in the centralarea of the lake where water depth was recorded as 18m., salinity was 30%0. No faunal sampling was carriedout at this station. Station D: (OS 7276 6378) Locatedat the extreme southwest end of the lake. Substrate consisted of consolidated peat with occasionalstones, depth varied from 50 cm to 2 m and salinity measured 30%0. Station E: (OS 7302 6419) Locatedon the northern shoreline of the lake, where a small stream enters and a small bed of Phragmites hasbecome established. Substrate in this area consisted of soft unconsolidated peat and smallstones, depth ranged from 0 to 1 m, and salinity measured 30%0. Station F: (OS 7329 6421) Located in the northeast ofthe lake where a small stream draining from a marshy pool, Little Drongawn Lough,enters the Lake. Substrate at this station consisted of large stones and rock with softpeat sediment filling the spaces between them. Depth varied from 15-60cm, and salinity measured 30%0. Station G: (OS 7313 6393) Locatedon the southern shoreline. Substrate consisted of stones, rock and soft peat, depth varied from 0-1 m and salinity ranged from 10- 28%0. No obvious stream enters at this point buta freshwater spring discharges just above the water level of the lake. A salinity gradientexists with distance from this

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Sneem 6 km

640 J

J Fig. 6.2.1Location Map of Sampling stations In Drongawn Lough, Co. Kerry J U

Table 6.2.1. Fauna Recorded in Drongawn Lough, Co. Kerry. Julyand September 1996. rl ( ) = records for July _ Sampling Stations ( L.T. = light-trap) rl r--A ,L.T.A B L.T.B D L T D E L.T.E F G 'L.T.G !Inlet Porifera Halichondria panicea + + + + _ -- -- - Cnidaria - -- j ri Chrysaora hysoscella +

Acanthopleura balk + T + + j + + j + Turbellaria ! j rI Nemertea +

Annelida Amphitrite edwardsi j + 1 - i Arenicola marina + ri Janua pagenstecheri + Nereidae + + Platynereis dumerili + + rj Poinatoceros triqueter + + + + T Spirorbis rupestris ! + + + + + + +

Crustacea I- j 0 Ostracoda Cirripedia Semibalanus balanoides + + + Verrttca stroemia + Ei Mysidacea Hemimysis lamornae 2

Neomysis integer j 1? Praunusflexuosus + 250 + 2 o 2 c 65 o 0 E

Isopoda Jaera sp. j + + + + Jaeraforsmanni T + + Ligia oceanica _ + P Amphipoda Ampithoe ramondi + + + + Caprella acanthifera +

Corophium volutator ( + j 0

Erichthonius difformis + + + j + + j r1 Gainmarus dttebeni i + + + Lembos longipes + + v

j j Melita palmata j --+ - + + Orchestia gaminarella j j ' j + 0 Tanaidacea j

Decapoda Carcinus maenas + + + + + j + Palaemonidae a j a a a j a a l a 0 Palaemon elegans + 1 + j o

P. longirostris + ! _ P. serratus + o - 0 Palaetnonetes varians + i a a a a i Arachnida Pycnoonida +

i Insecta - ' ------' i i 0 Thysanura -- --- Ephemeroptera' - ,-T-_-- -- _ ( --- Odonata Plecoptera ----r - -- ' Trichoptera --- I i HemipteraSigara dorsalis +

I i i j I I 0 + = present; o = occasional; c = common; a= abundant; F = fyke net n u Table 6.2.1. cont., Fauna Recorded in Drongawn Lough, Co. Kerry.July and September 1996. () = records for July

_Fauna; Sampling Stations ( L.T. = light-trap) A L.T.A B L.T.B D L.T. D E L.T.E i F G t..T.G Inlet

Coleoprte Haliplus wehnckei Diptera Chironomidae -- + +- + Mollusca ---- + - Prosobranchia Bittiiun reticulatum + c c 5 a 4 + + Gibbula umbilicalis +_

j jHvdrobia ventrosa + j + Lepidochitona cinerea +

Littorina littorea + + + j + + L obtusata + + + + L saxatilis + Onoba sp. + _ Patella vulgata + Rissoa membranacea + Rissoa sp. + isthobranchia Elysia viridis + Scaphander lignarius + 24 + + + Pulmonata

Bivalvia Anomia sp. j +

Cerastoderma glaucum a a + + j +

Chlamys varia + + + j Mytihis edulis a a a Ostrea edulis + + + + Venerupis sp. + Bryozoa Bowerbankia sp. + Cryptosula pallasiana + + + + + + J Echinodermata Asterias rubens + _ Amphipholis squamata + + + Tunicata Ascidiella aspersa + + + Clavelina lepadifonnis + + + + + + + j Dendrodoa grossularia I Teleostei Inguilla anguilla + F, 1 F,4 2 a j IAtherina presbyter + F,5 F.2 Crenilabrus melops j

_ IGasterosteus aculeatus ! + F,1 Gobius niger !. - Platichtltvs flesits - F,2 --- j Pomatoschistus micro s + + j + + 9 + + iJ

J l + = present; o = occasional; c = common; a= abundant; F = fyke net Drongawn Lough

point and the water during the sampling period was obviouslystratified even in very shallow water. Station I was an additional sampling station from within thenarrows of the lake (Plate 6.2.3). No salinity measurements were made. Water depth varied from0 to 25 cm and substrate consisted largely of a mussel bed on top ofstones and bedrock. The tide was seen to reach the water level ofthe lake on the final day of sampling but no tidal flow into the lake was observed.

Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 6.2. 1.Among 68 macrofaunal taxa listed, 60 are identified to species.A few need confirmation and specimens of 5 taxa were too small,only represented by females, or in poor condition. One "worm" remains to beidentified. The majority of recorded species are marine, 6 are poly-mesohaline (Arenicola marina, Praunus flexuosus, Melita palmata, Hydrobia ventrosa, Rissoa membranacea, Cerastoderma glaucum) and 6 are euryhaline (Neomysis integer, Gammarus duebeni, Carcinus maenas, Palaemonetes varians, Anguilla anguilla, Pomatoschistus microps), and two are limnic (Sigara dorsalis and Haliplus wehnckei). Only three insectswere taken, including single specimens of a corixid anda . Three species (Cerastoderma glaucum, Palaemonetes varians and Hydrobia ventrosa)are listedas lagoonal specialists in Britain (Davidson et al. 1991). The greatest number of species (27-3 1)was recorded among the rocks and mussels of the sea inlet (station A) and at stations B andD where the salinity was 30-32%0. Somewhat fewer species (24-29) were found at stations wherea salinity <30%o was recorded i.e. at E and F, and only 21 specieswere present at G where the salinity fell to 10%o in the region of a freshwater spring.

6.2.3Discussion

The fauna was rich and predominantly marine but with 18%of brackish (poly- euryhaline) species, three of which are recognisedas lagoonal specialists, and two limnic species.The conditions which favour the brackishwater speciesare the small tidal range coupled with a small, but probably continuous, freshwaterinflow from the surrounding peatlands. The corixid and beetle speciesare normally associated with freshwater and may have been immigrants froma nearby pond. The lake contains a natural population of large oysters Jaera forsmani may not have been officially recorded for Ireland,(possibly in L. Hyne) but there are unpublished reports of itsoccurrence. The only record of Frichthonius difformis in Ireland is for L. Hyne (Costelloel al.1989). Palaemon longirostris, which is regarded as an estuarine and brackish species,was not taken at any other site during this survey.

6.2.4Threats

The lake lies in asparsely inhabited area and there are no apparent threatsto the aquatic community.

5 J

Drongawn Lough

Mussels are farmed commercially in the adjacent inlet, and Drongawnmay be considered as a good site for mariculture e.g. oysters whichoccur naturally.

6.2.5Evaluation

Drongawn Lough is a natural saline lake with a shallow,constricted outlet. Geomorphologically, the lake is not a true lagoon but isa good example of a deep, "silted" lake in pristine condition. It is presumably of glacialorigin and is similar to Salt Lake and Lough Hyne and probably resembles the Scottish"obs". Very little is known about this lake. The lake has a rich and interesting aquatic fauna which includes two rare crustacean species. An interesting feature is the presence of lagoonal andfreshwater species in a community dominated by marine species. Further study of the fauna,to include a diving survey of the deeper regions, is recommended. The lake is a good example of a completely natural,moderately large, saline lake on the mountainous Kerry coastline in an almost perfect state ofpreservation. It lies between two small proposed NHAs (Site Code Nos.1375 and 2098). In conclusion, Drongawn Lough is considered to be of highconservation value and worthy of further study. The presence of two rare speciesqualify it to be considered as of national importance. Its designation as a proposed SAC isrecommended.

J 6.2.6References and Additional Sources of Information

J Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Costello, M.J., Holmes, J.M.C., McGrath, D. and Myers, A.A. 1989.A review and catalogue of the Amphipoda (Crustacea) in Ireland. Irish Fisheries Investigations Series B (Marine), 33: 3-70. J Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Irelands wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha.

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Drongawn Lough 0

Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. E,IFA/T23 (Suppl. 1). 507-518. 0 Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. 0 Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the 0 Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. 0

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go Plate 6.2.1View of Drongawn Lough from the inlet. r

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Plate 6.2.2 View of the narrow inlet of Drongawn Loughtaken from the lake. r

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Plate 6.2_ )View of Drongawn Lough from the inlet, Stations A (foreground) and B (island). a

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Plate 6.2.4 View of the narrow inlet of Drongawn Loughtaken from the hill, Station A. a

44 r. J

Drongawn Lough

6.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork n J Aims

The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

J 6.3.1Site Description(Fig. 6.3. 1)

This is a fairly rocky site set in a landscapedominated by bog vegetation and frequent heathy outcrops. The whole area is criss-crossed by dry stonewalls and subject to grazing.

The bedrock barrier lies across the northern end of thelagoon with the outlet to the sea at its eastern end. There is no inflowing freshwaterstream of any size, only occasional small drainage ditches and flushes.

The shores of the tough are mainly peat of irregularslope with occasional areas of low peat cliff. Bedrock outcrops occur occasionally along the south easternshore, forming small steep sided promontories in places. There is no swampvegetation. 7 LJ 6.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 6.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from the shore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant J species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

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0 Fig 6 3 2 Drongawn Lough, Co.Kerry : Location of Transects and Shore-based Survey Sections

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Drongawn Lough 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional specieswere found the grapnel 0 survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. 0

At each aquatic sample point measurements were taken of salinity (using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for 0 other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the 0 transect.

Representative examples of every marginal community encountered during thecourse 0 of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentagecover (using the Domin 0 scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentagecover value according to the Domin scale as follows: 0 Domin. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 6 26-33 % 0 5 11-25 % 4 4-10 % 3 <4 % -many individuals 0 2 <4 % -several individuals

1 <4 % -few individuals 0

a 9 Drongawn Lough

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % IV 61-80 % III 41-60 % II 21-40 % J I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall J Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the J sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

J The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel) except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences:

10 J u

Drongawn Lough 0 a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications 0

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha '. a

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (ThirdEdition). Scientific 0 names of charophytes are according to N.F. Stewart and J.M.Church, `Red Data Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic mhcrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection. 0

0

11 ri Drongawn Lough

A `Potentially Valuable ' .site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable'site is one that is shown to beof little or no interest. J The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

J 6.3.3Results t. Shore-based survey

Section A-B (Transect A)

J Aquatic: Filamentous algae- patchy Enteromorpha - patchy Fucus serratus - patchy Fucus sp. - patchy Codium tomentosum- sparse

J Bedrock and silt substrate

Marginal:Juncus maritimus tussocks with species-poor salt tolerant understorey dominated by Agrostis stolonifera.I m strip

Adjacent:Heath vegetation with Ulex europaeus, Calluna vulgaris, Erica cinerea, Potentilla erecta dominant ------

Section B-C (Transect B)

Aquatic: Ruppia c.f. cirrhosa- dense patches Filamentous algae- patchy Enteromorpha - patchy

Marginal:Juncus maritimus community as A-B. Extending back to c.50m at 7 bayhead, forming 1-2m strip along shore elsewhere lJ Adjacent:Unchanged ------

7 U

12 u

Drongawn Lough 0 Section C-D 0 Aquatic: Ruppia c.f cirrhosa- sparse Filamentous algae- extensive Enteromorpha- patchy 0 Fucus serratus- patchy

Marginal:Exposed bedrock shore with lichens. Occasional small patches ofJuncus maritimus dominated community as before Adjacent:Unchanged ------0 Section D-E

Aquatic: Ruppia c.f. cirrhosa- dense beds 0 Filamentous algae- extensive Enteromorpha - sparse 0 Marginal:Juncus maritimus community as before forming 1-2m strip along shore 0 Adjacent:Unchanged ------Section E-F 0 Aquatic: Filamentous algae- patchy Enteromorpha- sparse 0 Fucus serratus- patchy Fucus sp. - patchy Codium tomentosum- sparse 0

Marginal:Lichenous bedrock shore 0 Adjacent:Unchanged ------Section F-G 0

Aquatic: Ruppia c.f cirrhosa- dense beds c. 10m out, sparse to landward Filamentous algae- patchy Enteromorpha- sparse

Marginal:Juncus maritimus community as D-E C

Adjacent:Unchanged 0 ------

0

0

0 13 DrongaNvn Lough

Section G-H

Aquatic: Ruppia c.f cirrhosa - dense beds c. 10m out, sparseto landward Enteromorpha - sparse Fucus serratus - patchy Fucus sp. - patchy Codium tomentosum - sparse n u Marginal:Bedrock shore as E-F

Adjacent:Unchanged J

Section H-I

As F-G

J Section I-J

Aquatic: Unchanged

Marginal:Juncus maritimus community now to c.70m

Adjacent:Unchanged

Section J-K

As F-G

Section K-L

As I-J n Section L-M U As F-G

Section M-N

As I

Section N-O rl J As G-H

r-I 14 u Drongawn Lough 0

Section O-P (Transect C) 0 Aquatic: Ruppia c.f cirrhosa - cover and zonation unchanged Filamentous algae - patchy cover 0 Marginal:Juncus maritimus tussocks with Agrostis stolonifera, Festuca rubra and Juncus gerardii locally dominant below with more or less sparsesalt G tolerant associates. 1-20m

Adjacent:Bog vegetation dominated by Molinia caerulea, Schoenus nigricans, 0 Eriophorum angustifolium and Sphagnum spp. with frequent Myrica gale, Erica tetralix, Trichophorum cespitosum and Drosera rotundifolia

Section P-Q 0 Aquatic: Unchanged

Marginal:Juncus maritimus community as Transect C forming 1-3m strip along 0 shore

Adjacent:Heath as A-B 0 ------Section Q-R G Aquatic: Unchanged 0 Marginal:Unchanged

Adjacent:Bog vegetation as O-P with occasional heath as A-B ------Section R-S

Aquatic: - Unchanged

Marginal:Unchanged

Adjacent:Heath as A-B ------

15 n Drongawn Lough

2. Transects

Site: Dron awn Lough Transect code: A

Location: Outlet to sea Sample point: 1 Aquatic - 2m out Sample area: 16m2 4x4 Substrate: Bedrock, silt J Depth: 0 - 50 cm Salinit : 34arts per thousand NVC communit :----- Height cm Cover Total Plant 80

Fucus serratus 25 25 Fucus s p. 30 20 Enteromo ha 15 20 Filamentous algae 20 Codium tomentosum 6 < 1

Description: Fairly dense cover of al al community dominated bfucoids and filamentous species.

Site: Dron awn Lough Transect code: A Location: Outlet to sea Sample point: 2 Marginal Sample area: lOm2 10x1 Substrate: Peat, exp osed bedrock

Depth: ----- Salinit : ----- NVC communit :Undetermined Height (cm) Cover (%) Total Plant 95

Juncus maritimus 80 80 A rostis stolonifera 15 25 Glaux maritima 6 5 Tri lochin maritima 10 5 Planta o mantima 8 < 1 Samolus valerandi 10 < 1 Carex extensa 15 < 1

Description: Fair(dense cover of Juncus maritimus tussocks with A rostis dominantbelow J amongst species-poor salt tolerant community forming lm strip along theshore. Backing to heath vegetation on rising rockround. Dominantspecies - Ulex euro aeus, Calluna vul aris, Erica cinerea, Potentilla erecta.

16 u

Drongawn Lough 0

Site: Dron awn Lough Transect code: B 0

Location: Sheltered bay Sample point: 1 Aquatic - 30m out Sample area: 16m2 4x4 Substrate: Bedrock, silt 0 Depth: 60 cm Salinit : 26arts per thousand NVC communit :----- Height cm Cover 0 Total Plant 100

Filamentous algae 100 0

0 Description: Dense cover of filamentous algae only. 0

0

0

Site: Dron awn Lough Transect code: B Location: Sheltered bay Sample point: 2 Aquatic - 15m out 0 Sample area: 16m2 4x4 Substrate: Bedrock, silt

Depth: 50 cm : Salinit 23arts per thousand 0 NVC communit : ----- Height cm Cover Total Plant 100 0 Higher Plant 50

Ruis c.f cirrhosa 50 50 0

Algae 0 Filamentous algae 25 Enteromor ha 20 25 0

Description: Patch cover of Ruis growing t hrough patchy cover of Enteromor ha and 0 filamentous algae.

0

0

0

17 0 J

Drongawn Lough

Site: Dron awn Lough Transect code: B Location: Sheltered bay Sample point: 3 Aquatic- 2m out Sample area: 16m2 (4x4) Substrate: Bedrock,eat

Depth: 50 cm Salinit : 19arts per thousand NVC communit :----- Hei ht cm Cover Total Plant 90 Higher Plant 10

Ruis c.f cirrhosa 40 10

Algae

Filamentous algae 80

Description: Filamentous algae dominant with open cover of Ru ia.

Backing stone and earth barrier (height 70cm, width 50cm.

Site: Dron awn Lough Transect code: B Location: Sheltered bay Sample point: 4 Aquatic- pool Sample area: 16m2 4x4 Substrate: Peat

Depth.- 50cm Salinit : 16arts per thousand NVC communit :----- Height cm Cover %) Total Plant 70

Ruis c. f. cirrhosa 40 70

Description: Ruis dominant in semi-isolated pool (area c.6x4m. J

18 U

Drongawn Lough 0

0 Site: Dron awn Lough Transect code: B Location: Sheltered bay Sampleoint:5 Marginal Sample area: 16m2 4x4 Substrate: Peat 0

Depth: ----- Salinit : -----

NVC communit : Undetermined Height (cm) Cover (%) 0 Total Plant 100 a Juncus maritimus 80 75 A rostis stolonifera 15 30 Planta o maritima 10 < 5 a Glaux maritima 6 < 5 Tri lochin maritima 15 < 5 Samolus valerandi 10 < 1 a Carex extensa 20 < 1 0 Description: Fairly dense cover of Juncus maritimus tussocks over species-poor salt tolerant vegetation. A rostis stolonifera dominant amongst an otherwise sparse understore . 50m. 0 Backing Ulex euro aeus - Calluna vul aris -Erica cinereaheath.

0 Site: Dron awn Lough Transect code: C

Location: Peat cliff shore Sample point: 1 Aquatic - l Om out Sample area: 16m2 4x4 Substrate: Peat 0 Depth: 60 cm Salinity 34arts p er thousand NVC communit :----- Height (cm) Cover %) 0 Total Plant 100 Higher Plant 75 0

Ruis c.f cirrhosa 50 75 0 Algae 30

Filamentous algae 30 0

Description: Ruis dominant in extensive bed with filamentous alg ae restrictedto areas of D lower cover. 0

D

0

19 0 Drongawn Lough

Site: Dron awn Lough Transect code: C Location: Peat cliff shore Sample point: 2 Aquatic - 2m out Sample area: 16m2 4x4 Substrate: Peat

Depth: 50 cm Salinit : 34arts per thousand NVC communit :----- Height cm Cover Total Plant 80 Higher Plant 5

Ruis c.f cirrhosa 40 5

Algae 75

Filamentous algae 75

Description- Filamentous al gae dominant with sparse Ruis cover. Backing 70cm eat cliff

Site: Dron awn Lough Transect code: C Location: Sheltered bay Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: ----- Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 100

Juncus maritimus 70 60 A rostis stolonifera 20 20 Juncus erardii 25 15 Festuca rubra 20 15 Glaux maritima 8 5 Aster tri olium 20 5 Tri lochin maritima 10 < 1 Planta o maritima 8 < 1 Cochlearia an lica 5 < 1 Samolus valerandi 8 < 1 Carex extensa 20 < 1

J Description: Open cover of Juncus maritimus tussocks. A rostis, Festucaand Juncuserardii co-dominant below with more or less sparse salt tolerant associates.20m. Grading to bog vegetation dominated b Sphagnum s pp., Moliniacaerulea, Schoenus ni ricans and Erio hilum an ustifolium with Mricaale, Erica tetralix, Tricho horum ces itosum, Drosera rotundifolia.

20 Drongawn Lough

6.3.4Evaluation

`Potentially Valuable'

This is a tidal, rocky lagoon. Salinity was high attime of survey (34 parts per thousand in the main body of the lough). There isno major freshwater inflow stream.

Two fucoid species (Fucus serratus and an unidentified species)are abundant along the rocky stretches of the eastern and south eastern shores.Codium tomentosum is occasional in the vicinity of the outlet to the sea.

Ruppia c.f. cirrhosa is abundant and well distributed. Itoccurs in dense beds, usually more than ten metres out from the shore, around thewhole site with the exception of the outlet area. Dense patches are found in thenarrow sheltered bays of the north east.

Zostera fragments were found washed up on the shore buttheir origin is unknown.

Marginal vegetation is limited to a Juncus maritimus salt tolerantcommunity, typically forming a narrow strip associated with low peat cliffs, withoccasional areas of bedrock shore.

Drongawn Lough seems to be a good representative ofa tidal, high salinity lagoon. Its Ruppia beds are extensive and other interesting aquatic speciesmay be present.

Aquatic areas were surveyed almost entirely from the shore dueto water depth.

Full aquatic survey is recommended.

21 Drongawn Lough J

6.4 ECOTONAL COLEOPTERA

J.A. Good PhD MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork.

6.4.1Site Description

Saline lake with channel to sea, and small tidal response.Lake shore with eroded cliffed peat margins, boulders and outcropping rock. Extensive margins of Juncus maritimus/pastureon peat.

Subsites (Fig.6.4.1)

1. Juncus maritimus (South-west) (V730638) c. 0.2 ha area ofJuncus maritimus with grass, Plantago maritima,Armeria maritima, etc., on peat, flooded during winter. Near-shore salinity 22%0 (1 ix 1996).

J 2. Juncus maritimus (North-west) (V 727638) Vegetation as above, but part of more extensive Juncus marginalong north-west margin of lake.

3. Rock., shore_ (V 731639) Cobbles between unvegetated zone and grass, etc., on organic/coarse sandsoil on rocky shore. n 6.4.2 J Methods Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

J As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites. n Therefore, species were selected as indicators of conservation value if: (1) they have a J restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

22 Fig. 6.4.1Map of sampling sites (Carabidae and Staphylinidae) at Drongawn Lough,Co. Kerry. 0

i- Cobble search 2 - Pitfall traps, J-vac 3 - Pitfall traps 0

0

0 Drongawn Lough

Interpretation of Indicator Species J Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14,for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin J spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites. J Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with J freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

.1 Sampling Techniques The sampling methods used are listed in Table 6.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the'D-vac' suction sampler) has asuction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves.

23 Drongawn Lough 0

0 TABLE 6.4.1. Details of sampling methods. 0

Method Details No. replicates Sampling period, etc. 0 per unit sample

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 0 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and plastic funnels; collars used G where cattle/horses occur Cobble samples Cobbles turned 0.5- 2 m 30 from water margin 0 Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; 0 agitated soil floated in water

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during a warm weather without rain

0 Habitat features associated with the sedimentary barrier, suchas shingle cobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs,were also sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 u hour) during warm dry weather, ora fixed number of cobbles turned (n = 30) orcliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during latesummer and early autumn (late July to early October), 0 with some sites visited in June. Thiswas unavoidable, and due to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring speciesmay be absent. 0

Variety of sampling techniques 0 Several techniques will always givea more robust picture of the fauna of a site, because any weather- or site-affected bias inone technique will be compensated by E other sampling methods. Some sites did notpossess suitable habitat (peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground searchor cobble search. This is regarded as an absence of habitat, rather thanan unavailable sampling opportunity. 0 That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site. 0

a

0 24 0 J

Drongawn Lough

Flooding of pi fall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is J difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6 traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >1m) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. J This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna - a definition proposed for use in sitesurveys. Bull. Jr. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : Juncus maritimus (South-west) area - S-vac suction sampler (19 ix1996), c. 2 m2; Juncus maritimus (South-west) area - 6 plastic pitfall traps withfunnels and ethylene glycol preservative (1 - 19 ix 1996); Rocky shore - cobble search (30 cobbles, 1 ix 1996); Juncus maritimus (North-west) area - 6 plastic pitfall traps withfunnels and ethylene glycol preservative (19 ix - 19 x 1996).

Species were selected as indicators of conservation value if: (1)they have a restricted habitat preference to a specific type of microhabitat associated with the lagoon margins; and, (2) they

25 Drongawn Lough 0

are reported in the literature as being local or rare,from which it is assumed that theyare less likely to survive in historically degraded ecosystems. 0

6.4.3Results 0

Six species of carabid and ten species of staphylinidwere recorded, one species of which is regarded as an indicator species (Table 6.4.2). 0

There are three pevious Irish records of Stenus lustrator (Anderson1984), which appears to 0 be local in Europe (Horion 1963). The species is tyrphophilous(associated with peat), but also occurs on marshy shores and flood meadows, accordingto Koch (1989). The Irish records are from bogs (Anderson 1984), and the specieswas also recorded at Lough Aconeera 0 and Faranamanagh Lake in this survey, both of whichposess peat and bog margins 0

TABLE 6.4.2.Carabidae and Staphylinidae (Coleoptera) recorded from DrongawnLough. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0

0 Species No. individuals

Carabidae a

Agonum fuliginosum (Panz.) 1 0 Agonum muelleri (Hbst.) 2 Bembidion mannerheimi Sahlb. 6 Dyschirius globosus (Host.) 5 0 Notiophilus biguttatus (F.) 1 Pterostichus niger (Schall.) 6 0 Staphylinidae

Atheta vestita (Grav.) 1 0 Cryptobium fracticorne (Payk.) 2 Drusilla canaliculata (F.) 8

Gabrius pennatus Sharp 1 0 Paederus fuscipes Curt. 34

Stemis brurmipes Steph. 1 Stenus juno (Payk.) I 0 * Stenu.v lustrator Er. 7 Indicator species Stenus nitens Steph. 1 0 Zyras limbatus (Payk.) I

0

0

26 0 Drongawn Lough

6.4.4Evaluation

Of low conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating

The presence of one peat-soil indicator species and a relativelylow species diversity indicates that these margins may be more disturbed than at othersites (e.g. L. Tanai, Co. Galway). The site can therefore only be rated as of low value.However, unlike at Lough Aconeera, the indicator species was present in numbers.

References

Anderson, R. (1984) Staphylinidae (Coleoptera) in Ireland- 3: Steninae. Ir. Nat. J. 21: 242- 251. Horion, A. (1963) FaunistikderMitteleuropdischen Kdfer. IX. Staphylinidae: Micropeplinae his Euaesthetinae. Feyel, Uberlingen-Bodensee. Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die Kdfer Mitteleuropas. 12.1. Supplementhand mit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die Kdfer Mitteleuropas. Katalog. Goecke & Evers,Krefeld.

J

J

27 Drongawn Lough

6.5 SUMMARY AND EVALUATION

Drongawn Lough is a medium-sized (20 ha) natural saline lakewith a shallow, constricted outlet. J Very little is known about this lake. It lies betweentwo small proposed NHAs (Site Code Nos. 1375 and 2098). J The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology High Aquatic Fauna High Vegetation Potentially High Ecotonal Coleoptera Low

Geomorphology.

The lake is a good example of a completely natural,moderately large (20 ha), saline lake on the mountainous Kerry coastline in an almost perfectstate of preservation. Geomorphologically, the lake is not a true lagoon but isa good example of a deep, "silled" lake in pristine condition. It is presumably of glacialorigin and is similar to Salt Lake and ough Hyne and probably resembles the Scottish"obs".

Although not a coastal lagoon in the strict sense, asa saline lake it is rated as of high conservation value based on its relatively large size and almostcomplete state of natural preservation.

Aquatic Fauna

Among 68 macrofaunal taxa recorded, 60 were identified to speciesincluding three lagoonal specialists (Cerastoderma glaucum, Palaemonetes varians and Hydrobia ventrosa).

The fauna was rich and predominantly marine but with 18%of brackish (poly- euryhaline) species, three of which are recognised as lagoonal specialists,and two limnic species. The conditions which favour the brackishwater species arethe small tidal range coupled with a small, but probably continuous, freshwaterinflow from the surrounding peatlands. The corixid and beetle species are normally associatedwith freshwater

28 and may have been immigrants from a nearby pond. Thelake contains a natural population of large oysters

Jaera forsmani may not have been officially recorded for Ireland,(possibly in L. Hyne) but there are unpublished reports of its occurrence. Theonly record of Erichthonius difformis in Ireland is for L. Hyne (Costello etal.1989). Palaemon longirostris, which is regarded as an estuarine and brackish species,was not taken at any other site during this survey.

The lake has a rich and interesting aquatic fauna whichincludes two rare crustacean species. An interesting feature is the presence of lagoonal andfreshwater species in a community dominated by marine species. Further study of the fauna,to include a diving survey of the deeper regions, is recommended.

In conclusion, the presence of two rare species qualify itto be considered as of national importance. The richness of the site and near pristine conditionsqualify Drongawn Lough to considered as of high conservation value and worthy of furtherstudy.

Vegetation

Ruppia c.f cirrhosa is abundant and well distributed. It occursin dense beds, usually more than ten metres out from the shore, around thewhole site with the exception of the outlet area. Dense patches are found in the narrowsheltered bays of the north east. Zostera fragments were found washed up on the shorebut their origin is unknown.

Marginal vegetation is limited to a Juncus maritimus salt tolerantcommunity, typically forming a narrow strip associated with low peat cliffs, withoccasional areas of bedrock shore.

Drongawn Lough seems to be a good representative of atidal, high salinity lagoon. Its Ruppia beds are extensive and other interesting aquatic speciesmay be present.

As aquatic areas were surveyed almost entirely from the shoredue to water depth the site is given a rating of "potentially valuable" and afull aquatic survey is recommended.

Ecotonal Coleoptera 0

Six species of carabid and ten species of staphylinid wererecorded, one species of which is regarded as an indicator species 0

There are three previous Irish records of Wnus lustrator, whichappears to be local in Europe. The species is tyrphophilous (associated with peat), but alsooccurs on marshy 0 shores and flood meadows, according to Koch (1989). The Irishrecords are from bogs and the species was also recorded at Lough Aconeera andFaranamanagh Lake in this survey, both of which posess peat and bog margins 0

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The presence of one peat-soil indicator species and a relativelylow species diversity indicates that these margins may be more disturbed than atother sites (e.g. L. Tanai, Co. Galway). The site can therefore only be rated as of low value. However, unlike at Lough Aconeera, the indicator species was present in numbers.

Summary

Very little is known about this lake. There appear tohave been no previous studies, or exploitation of the lake, although mariculture might be considered. Thereis very little disturbance to the site apart from occasional duck shooting andfishing. Geo morphologically, the lake is not a true lagoon butis a good example of a deep, "silled" lake in pristine condition. It is presumably of glacialorigin and is similar to Salt Lake and Lough Hyne and probably resembles the Scottish"obs". A mixed community of marine and lagoonal fauna and florais of interest On the basis of geomorphology as a saline lake andits aquatic faunal and floral communities, Drongawn Lough is regarded as of high conservation value. Proposal as an SAC is recommended.

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J COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

J 7. LOUGH GILL

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

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J Prepared for the National Parks and Wildlife Service

(BioMar/Life) J 7. LOUGH GILL J

J CONTENTS 7.1 Study Area

7.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

J 7.2.1Methods 7.2.2Results J 7.2.3Discussion 7.2.4Threats 7.2.5Evaluation 7.2.6References

7.3 Vegetation Survey (Pat Hatch)

7.3.1Site Description 7.3.2Methods 7.3.3Results Transect tables 73.4Evaluation

7.4 Ecotonal Coleoptera (Jervis Good)

7.4.1Site description J 7.4.2Methods 7.4.3Results r, J 7.4.4Evaluation 7.4.5 References

7.5 Summary and Evaluation

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7. LOUGH GILL, Co. Kerry

OS Grid Reference: Q 606 142, 1:50,000 Sheet Nos. 70/71 J Alternative names: Loch Gile

7.1 STUDY AREA

Generalfeatures Lough Gill is situated on the north coast of theDingle peninsula, 1 km from the town of Castlegregory. The lake is a shallow natural lagoon ina classical position" (Guilcher & King 1961) lying between two barriers which uniteto form a tombolo i connecting the mainland to a group of the Magharee islands.This tombolo is known as the Castlegregory spit with Brandon Bay to the east andTralee Bay to the west (Fig. 7. 1. 1). A freshwater stream enters in the southwestand a channel (The Trench) runs from the northeast of the lake to Tralee Bay, buttidal exchange is limited by a one-way r1 sluice at the outlet and a small weir which preventsall but the highest tides from J entering the lagoon. The lagoon is a state-owned Wildfowl Sanctuary, andan SPA for birds, although Sheppard (1993) points out that peak waterfowl counts have declineddrastically from those quoted by Hutchinson (1979). The Tralee Bay and MaghereesPeninsula is a proposed NHA (Site Code No. 2070). An Foras Forbartha listedthe site as of special 7 scientific importance with a national rating of botanical, geomorphological,zoological LJ and ornithological importance. The L. Gillarea is also of major importance as the main breeding site of the Natterjack toad (Bufo calamita) (seeGresson and O'Dubada 1971) and is scheduled for designationas a National Nature Reserve. The Castlegregory Golf Club has a 20 year leaseon the warren at the western end of the lake. J A golf course has recently been extended in thearea of dunes which borders the southwest shoreline of the lake. This extension intoa natural dune area and breeding site of Natterjack toads was highly controversial, but permissionwas granted and the golf course itself does not appear to affect the lake.Land between the lake and the sea has escaped tourist development. The golfcourses extension, although damaging the original dunes is sown with Festuca rubra andno fertilisers are used. Grazing is continued in winter and spring, thus preventing invasion by scruband allowing the diverse herbaceous flora to grow.

Climate and oceanographic influences J (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 6.5°C in January and15.5°C in July. The growing season (the period of mean daily air temperatures above 6°C) is1 1 months and as snow and frosts are rare, some plant growth is possiblein winter months. Annual

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Lough Gill

rainfall is approximately 1400 mm, and the number of raindays (I mm or more) is J 175-200. Prevailing winds are from the south and west. Meanannual hourly wind speeds are between 5.6 m/s and a maximum wind speed of 49-50 m/s is estimated to occur once in 50 years. The daily duration of brightsunshine averages 3.5-4.0 hours. Mean relative humidity is around 85% as on all Irishcoasts. Marine processes in the area are dominated by long periodAtlantic swell waves with u median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 in (Carter 1992).Maximum wave heights (averaging once in 50 years) are 30-35 m(Couper 1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS) in Tralee Bay is4.2 m (Admiralty Tide Tables). Landscape and Geology The bedrock of the coastline is composed of limestone, giving rise to alkaline groundwater, often covered by glacial driftor dunes. Inland, the limestone is overlain with sandstones and slates of the DingleBeds. Most of the lagoon is bordered by dunes and dune grassland to the northand by peaty podzolic soils to the south. The surrounding agricultural land consists mostly of improvedpastureland, and it appears that milk production has become more intensiverecently. Land rises J steeply from the coastline to mountains of Old Red Sandstone(R.I.A. 1979) which run the length of the peninsula.

Lake Topography The lake is approximately 2.5 km from southwest to northeast, width varies from 3-400 m in the narrow southwestern endto almost 1 km from central to northeast end and total area is approximately 160ha. The lake is very shallow (30-40 cms) except in the dredged channels at bothends of the lagoon. The substrate is mostly firm sand and it is possible tocross most of the lake on foot. It appears that until recently most of the bed of thelagoon was covered with extensive areas of Chara, but these seem to have been out-competedby blooms of filamentous algae.

Hydrology A freshwater stream enters in the southwest and a channelruns from the northeast of the lake to Tralee Bay, but tidalexchange is limited by a one-way sluice at the outlet and a small weir which preventsall but the highest tides from entering the lagoon. The bridge, with sluices to prevent seawaterfrom entering, was built in 1929. Kerry Co. Council dredged the outlet channel,known as The Trench" and removed the sandbar which was then blocking the outletin 1971. The first weir J was constructed to maintain higher water levels in the lakesome time after 1971. The weir was removed in 1981 and then replaced again in1983. (Sean Bowler pers. comm.). There is no tidal fluctuation in water level of thelake, but a seasonal one whereby water levels rise in the winter with the increased rainfall,and gradually decline to J sometimes very low levels in the summer. Salinity and water quality Seawater enters the lagoon less frequently since construction of the sluice and the weir. However, neither appearto function perfectly and recent water analyses carried out at U.C.D. show theundeniable presence of seawater within the lagoon, despite the fact that it iswidely regarded as being completely fresh.

J 2 Lough Gill D

Although the surrounding hills are acidic and streams entering thelake have a low pH, it appears that alkaline ground waters also enter the lake,and the water is generally 0 base-rich, which is unusual for a wetland in this partof Ireland. There have been considerable problems with eutrophication in this lake,presumably EJ due to agricultural runoff and waste discharge from the townof Castlegregory. Blooms of filamentous algae have been common recently. The lakeis an important trout fishery and the first serious fish-kill occurred in July1984. 0

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7.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver, Dept. of Zoology, University College Dublin

J 7.2.1Methods

Environmental variables Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1%0. precision). As salinity levels were very low, water sampleswere collected for subsequent analysis. A photographic recordwas made of the site and local information J sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. J Fyke nets were used at stations A, B, and Fin order to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets J used are referred to as summer Tyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination J All sampling methods used in the surveyare affected by many environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often with a different samplingmethod. The results of

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13 0 --- 1 C7 C O O C] C3 C7 O O O 59 Fig. 7.2.1 Location Map of sampling stations in lough gill, Co Kerry 60 C3 C7 61C3 C3 C3 C3 C3 C7 O C3 62 O J C 7 c C__] C C__3 : I U r Table 7.2.1.r] CJ U U C1 U C 7 Fauna Recorded at Lough Gill, Co. Kerry. July and September, ( ) = records from July. C-7 Ci 1996. C-] U U C Inlct L.T. A Sampling BStations C (L.T. = light-trap) E F G H I CnidariaPorifera ------_NemerteaTurbcllariaAnnelida -- -- - ClitellioHirudinea aren.arius + + + + - --- - ++ - -+ Crustacea --- Ostracodal Naididae------+ + + + + + + + + ------+ Copepodat _ + + + + -_ --- Ci - - 1 M sidacca rred i=) Neornysis integer + + + + c 0 + -- --_ Amphipod_i Isopoda - MehlaGa,n,rtrusLekanessrhaera-ltookeri paltnata zaddachi - - - + + + + - +a + - l -- Tanaidace i I Arachnids - Decapoda Hydracarina_ -- - 12 - -- + - -- - + + ------i -_ - + -- + -- Insecta l - - Ephuncroptcra Thysanura iCtoeort .simile + + -+ - - - Procloeonlsehn,u hifidurrt a ele , ctns + + + + + - + I + + Odonata t f - TrichoptcraPlecoptera Ne a cinerea + = present; o = occasional; c = common; a + = abundant; F = fyke net + + Table 7.2.1 cont.. Fauna Recorded at Lough Gill, Co. Kerry. July and September, ( ) = records from July. 1996. Inlet L.T. A L.T.A SamplingB Stations L.T.B C ( L.T. = light-trap) E L.T.E F L.T.F G H L.T.H. I L.T.I CorixaCallicoriCorixidae unctata a praeusta + + + 100 + + 150 + + + + + 300 oa + 65 (+) + ++ --- ArctocorisaC pan, eri germari cuadorsalis a a+ +a +a a a a + aa + +a +a + +c c c c Cole ptcra HaliEnochrns )hts:Cercyon testacns sternalis conftnis + + + ++- H. linealocollis + + (+) -- LaccobinsHyrunts inaequctlis biguttatus + + ------(+) NebrioponcsLlvbiusLaccophilus ininutitsdepresses ig inosus + + ------MulluSCtt Polyplacophora Diptcral j TiChironomidae ------

+ + +_ + + I Lepiclochitona cinerea - - - - - _ . OpiSthubranchia Prosobranchial Puimunatal PotarnopvrgnsHydrobiidae antipodarum -- -

Lv,nnaen ere gra + + + + +

+ + +

+ + +

+ + + + +

+ + + + +

+ + ------+ ------L. ntituatts ------+ - --- - _ + + + ------. ------_ _. ------_. ------I + 1 - - 0 0 0 0 0 0 l 0 0 c + = present; o = occasional; c = common; a ** = First Irish record 0 0 o a o o f 0 0 0 = abundant; F = fyke net + C__7 7J L_7 U U C"1 Table 7.2.1 cont.. L_-] L_3 U U CI L_I Fauna Recorded at Lough Gill, Co. Kerry. July and September, ( ) = records from July. LI L] U C7 L_3 1996. L_3 C3 E- -j L_. ------Inlet Sampling Stations ( L.T. = light-trap) I Cerczstoderntn5'ernentina coat lanata + L.T. A L.T.A B L.T.B C E L.T.E F L.T.F G H L.T.H. + + L.T.I Biv

Teleostei AnguillaGasterosteus ctngnilla aculeatres 1 F,1 F,46 + F, 94 -- -- + ---- + ------+ Mugilidae Plauc/tt/ryti Jlesres a 49 F, 23 a 130 +a 14 c e 4 F, 3 + F, 6 +

+ +

+ 4 +

+ +

------POt"ICttOSClti a(S micro is sit. ------+ ,Salrno truttct ------F, 3 F, 2 c - + I + = present; o = occasional; c = common; a = abundant; F = fyke net u

Lough Gill 0

the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution 0 within the water column. Abundance categories ofpresent, common and abundant are purely subjective, and absolute numbersvary between taxa. 0 Several faunal groups were sorted and distributedto specialists. Standard keys were used to identify remaining specimens, but many of thesewere larval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for 0 identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (e.g.hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify when preserved 0 (turbellarians, leeches). All Diptera are identified to family level. All Odonata positivelyidentified were 0 Ischnura elegans and it s assumed that early instars ofthis group were of the same species. ri 7.2.2Results Lough Gill was sampled on 6.vii.96 during the firstpart of the survey, and from 11- 0 13.ix.96 during the more intensivesurvey. Stations were selected within the lake to reflect the influencesof fresh and saline water rI and differences in vegetation and substrate. Positions of thesampling stations are shown in Fig. 7.2.1 0 Environmental Variables Station "inlet" was an additional sample site in thearea where boats are launched 0 near the golf club, approximately 50 m up the streamwhich leads into the lake. This inlet had been dredged and depthwas approximately 2 m, substrate was sand and salinity measured 0 %o (Plate 7.2. 1). 0 Station A (OS 5933 1346) was located at the southwestcorner where the freshwater stream first enters the lagoon. to In this area waterdepth varied from 25 cm to 1 m, substrate was sand and salinity measured 0%o (Plate 7.2.1). 0 Station B (OS 5956 1381) was located along the northernshoreline at the end of the golf course. Water depth varied from 25-80cm , substrate consisted of sand with 0 occasional stones, salinity measured 0%o Station C (5967 1341) was locatedon the southern shoreline of the narrow arm of the lake, just east of Drom Point. Water depth varied from0- 50 cm., substrate consisted a of stones and fine organic silt, salinitywas 2%0. Station D (OS 5983 1373)was located in the open water area of the lake.salinity 0 measured 2%o and substrate was sand. No faunal samplingwas carried out at this station. 0 Station E (OS 6030 1396) was locatedon the northern shoreline in a bay formed by Phragmites. Substrate in this area consisted of firm sand, depth rangedfrom 40-50 cm and salinity measured 2%o (Plate 7.2.2). 0

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Station F (OS 5955 ?? 1382) was located on thesouthern shoreline of the lagoon at the corner where the lagoon widens. This is the deepestarea of the lagoon ( 2 m), substrate is fine organic silt and salinity measured 2%0. Station G (OS 6077 1349) was located on the southernshore where a small stream enters and cattle drink. Substrate was rich organic mud, depthwas 0-25 cm and salinity measured 0-1 %o. Station H (OS 6122 1464) was located at the northeastcorner where The Trench connects the lake to the sea. Substrate was clean sand,depth varied from 25-50 cm, and salinity measured 2%o (Plate 7.2.5). Station I (OS 6134 1403) was located beside the jettyat Lough Beg Cottage. Substrate was sand with occasional rocks and stones, some ofwhich had fallen from the jetty, depth varied from 25-50 cm and salinity measured1-2%0.

J Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 7.2. 1. Among 43 taxa listed, 35 are identifiedto species; Trichoptera remain to be identified and the bryozoan needs confirmation. No attempt willbe made to identify Hirudinea, Hydracarina, Larvae of Chironomidae and Tipulidae, Pisidium and Sphaerium spp. or the polychaete which is in poor condition.One marine species was recorded (a chiton, which was presumably an accidental introduction), 3are poly- mesohaline taxa, 7 are euryhaline, 2 are oligo-mesohaline and 25are limnic (Table J 7.2.2). One species (Lekanesphaera hookeri) is listed as a lagoonalspecialist in Britain (Davidson et al. (1991). Some limnic taxa (Hirudinea, Ephemeroptera, Trichoptera) were found only inthe inland sector of the lake i.e. stations A, B andC, while others (Hydracarina, Corixidae, Coleoptera and molluscs) were more widespread, extending into an areawhere the salinity was 2%o in September and 5%o in July. Mostof the beetles were taken in light traps and could have been attracted by the lights whileflying. Some brackishwater species e.g. Lekanesphaera hookeri and Pomatoschistus microps were confined tothe area near the mouth of the sea inlet while otherse.g. Clitellio arenarius and Neomysis integer were more widely distributed. Juvenile flounder and mullet, allof which were under 15 cm, had probably entered in the current year. Table 7.2.2Ecological categories of the recorded taxa in Lough Gill (Trichoptera not included). L = lagoonal specialist according to Davidson etal. (1991).

Marine Lepidochitona cinerea

Poly-mesohalinc Clitelho arenarius A,felita pahnata Mugilidae

Euryhaline iVeomvsis integer Lekanesphaera hookeri L Gannnarus zaddachi .=1 nguilla anguilla J Gasterosteus aculeatus Pomatoschistus microps Platichthvs flesus

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Oligo-mesohaline Ischnura elegans 0 Potarnopyrgus antipodaruin 0 Limnic Hiudinea Hydracarina Cloeon simile Prcloeon bifiduin 0 Nepa cinerea Callieorixa praeusta Corixa punctata 0 C. panzeri Arctocorisa germari Sigara dorsalis 0 *Cercyon sternalis Enochrus testaceus Haliplus confinis H. fulvus 0 H. lineatocollis Hygrotus inaequalis Laccobius biguttatus 0 Llybius fuliginosus Nebrioporus depressus Lymnaea peregra Sementina complanata 0 Pisidium sp. Sphaerium sp. Plumatella repens 0 Salmo trutta

0 * New Irish record

7.2.3Discussion 0

The fauna is rich and diverse, comprising both freshwater andbrackishwater elements. Hemiptera (6 spp.) and Coleoptera (11 spp.)were especially abundant and diverse. 0 The faunal assemblage typifies a system which is essentially freshwaterbut which receives small incursions of seawater. All of the hemipterans andbeetles are freshwater species. The long, sluiced inlet and weir apparently prevent crabsand prawns entering 0 the lake but juvenile flounder and mullet were able tofind their way in during 1996. Cercyon sternalis is a new record for Ireland. This andfour other beetles were not 0 recorded at any other site during the survey.

7.2.4Threats 0

There have been considerable problems with eutrophication in this lake,presumably 0 due to agricultural runoff and waste discharge from the townof Castlegregory. Blooms of filamentous algae have been common recently. The lakeis an important trout fishery and the first serious fish-kill occurred in July1984. Allowing seawater to 0 enter may help to control the algal blooms but expertadvice is needed before this is attempted. 0

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The golf course has recently been extended in the areaof dunes which borders the J southwest shoreline of the lake. This extension into a natural dune area and breeding site of Natterjack toads was highly controversial, but permission wasgranted and the golf course itself does not appear to affect the lake.The golf courses extension, although damaging the original dunes is sown with Festuca ruhraand no fertilisers are used. J Land between the lake and the sea has escaped touristdevelopment. Grazing is continued in winter and spring, thus preventing invasion by scruband allowing the diverse herbaceous flora to grow. Unauthorised drainage and development of water sports may still bea threat.

7.2.5Evaluation

Lough Gill is a natural sedimentary lagoon with a sandbarrier and therefore of J international importance based purely on geomorphology.

Geomorphologically it is a classic example of a lagoon lyingbetween two sedimentary J barriers. However, salinity levels, determining the biological community, are controlled by management. If seawater was allowed to enter on aregular basis the lake would merit more protection as a classic brackish lagoon.

The lake lies within a proposed NHA. It is aWildfowl Sanctuary and an SPA for birds, although peak waterfowl counts have declined drastically since 1979. Thedune area is of major importance as the main breeding site for theNatterjack Toad.

The lake is an important trout fishery and of greatconcern to the local inhabitants.

The aquatic fauna appears to be diverse and consists mainlyof freshwater species but a J significant brackish element is also present which includes a lagoonalspecialist. An aquatic beetle is recorded for the first time in Ireland.

J In conclusion Lough Gill is of high conservation value. Itsconservation value as a coastal lagoon, however, depends entirely on management. Designation as a proposed SAC is recommended. However, the predominance of freshwater species amongthe Li aquatic fauna and the localised occurrence of the single lagoonalspecialist near to the sea inlet, casts some doubt upon the acceptance of the lake as a true lagoon based on the fauna alone. J

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7.2.6References and Additional Sources of Information 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department 0 Anon. 1974. Report on Wetlands of international and national importancein the Republic of Ireland. Forest and Wildlife Service, Department of Lands,Dublin. An Taisce. Report on the Lough Gill Natural Heritage Site. 0 Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. 0 Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. 0 Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeB Report 1994-1995. IWC Birdwatch Ireland. 109pp. Gresson, R.A.R. & S O'Dubada. 1971. Natterjack Toads Bufo calamitaLaur. at 0 Castlegregory an Fermoyle, Co. Kerry. Ir. Nat. J., 17: (1)9-11. Guilcher, A. & C.A.M. King. 1961. Spits, Tombolos and TidalMarshes in Connemara and West Kerry. Proc. R.Ir. Acad. 61: 283-338. 0 Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. a Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. IJ Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. EJ Merne, O. 1989. Important bird areas of Ireland. In: Grimmett,R,F,A, and Jones, T.A. (eds) Important bird areas in Europe. ICBP Tech. Publ.No 9, Cambridge. 888 pp. 0 Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) 0 in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis. Dublin University. Praeger, R.L. 1950. The Natural History of Ireland Collins. London. 0 Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 0 PP. Sheppard, R. 1993 Irelands Wetland Wealth. Irish Wildbird Conservancy, 152pp. Speight, M.C.D. 1982. Arcocera globules, Limnia paludicola and Sphaerophoria 0 loewi: Insects new to Ireland. Ir. Nat. J., 20 (9):369-372. 0

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EJ Plate 7.2. 1 View of freshwater inlet entering southern end of Gill, StationA.

Plate 72.2 View of the northwest shore of Lough Gilllooking west, Station E. J

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Plate 7.2.; View looking north across Cough Gill towards thesandhills.

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Plate 7_2.4Photograph of as yet unidentified freshwater Bryozoan found in LoughGill r

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Plate T2. 5View of the area near the outlet of rough Gill,Station H.

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Plate 72.6 View of the weir on the outlet channelof Lough Gill.

A Lough Gill

7.3 VEGETATION SURVEY J Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

J 7.3.1Site Description(Fig. 7.3. 1)

Low-lying pastoral farmland lies to the south of this loughwith mountainous country beyond. The sea lies beyond sand dunes to the north,north east and west.

The major freshwater inflow discharges into the lough at itswestern end and the outlet to the sea runs from the opposite, eastern end. Fairlyextensive Phragmites dominated swamps occur at the freshwater inflow and bordering the southernshore. A narrow strip of swamp vegetation fringes most of the northern shoreand Scirpus and Schoenoplectus swamps are found at the eastern end.

The only open shores are in the south west where,according to local knowledge, an area of pasture has been extended into the lough bya local landowner. A golf course adjoins the lough to the north west. J Shores are shallowly sloping around the whole site.

J 7.3.2 Methods

This site was surveyd by means of transects only. Thelocality of these is shown in Fig. 7.3.2.

J Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described. J The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

J One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic J

10 KEY: PaUSPomit,t4vtf 57er-ie5 - - PGtrU 5Wd.wlFlFen fes Goctes l s Fig. 7.3.1 GM , Co. Ket-ry - Mcwgincd VegefufioYg 5wt4Y - 5,-irpu5 wlau5 O D n O O O D O O D O D D D O O D D D O Ipse5(ccc - ssP,5ckoevtor(eci'u5IYiS tub s C r :ON C_:= L,:n C-I L_

N Fig. 7. 3.2 Lough Gill, Co. Kerry: Location of Transects u

Lough Gill 0 survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand n refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out, meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for 0 other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 6 26-33 % 0 5 11-25 % 4 4-10 % 3 <4 % many individuals 0 2 <4 % several individuals 1 <4 % few individuals 0

Frequency Values 0 Frequency of each species within the total number of samplesis expressed as follows: a

11 J

J Lough Gill

J Frequency V 81-100 % IV 61-80 % III 41-60 % J II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy. J The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located at the outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course. J Adjacent habitat and land use was described in general terms and dominant species recorded. J A brief site description was written for each lagoon.

J Constraints

Time. Restrictions on the time available in which to carryout this survey had the :1 following consequences: a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications J Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service J

12 u

Lough Gill 0

0 Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous 0 green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0 Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0 Nomenclature

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin 0 & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0

Evaluation 0 This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey. 0 The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not 0 a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic mhcrophytes. Due to the difficulties in obtaining determinations for filamentousgreen 0 algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0 A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection. 0 A `Potentially Valuable ' site is one which thissurvey indicates may be of interest and which may prove to be valuable following furthersurvey- 0 A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-basedsurvey and not a full aquatic survey (see 0 `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged. 0

0

0

0

13 J

Lough Gill

J 7.3.3Results Transects

Site: Lough Gill Transect code: A rl Location: Outlet to sea Sample point: 1 Aquatic - 100m out UI Sample area: 25m2 5x5 Substrate: Sand

De the 50 cm Salinit : 0arts per thousand

NVC communit : ----- J Height (cm) Cover Total Plant 80 Higher Plant 70

Ruis maritima 5 70 J Algae 50 r] J Filamentous algae 50

U Description: Fairly dense low growing Ruis some in flower beneath patchy cover of free- floatin r1 filamentous algae. Same species at more or less thesame cover at 75m, 50m, 25m and J 10m out from the shore. Water depth gradually decreasing to30cm at 50m out, remaining constant to 3m out.

J

Site: Lough Gill Transect code: A Location: Outlet to sea Sample point: 2 Aquatic- 3m out Sample area: 25m2 (5x5 Substrate: Sand

Depth: 20 cm Salinit : 0arts per thousand

NVC communit : ----- Height cm Cover (%) 7 Total Plant 80 U Higher Plant 60

J Ruis maritima 5 60

Algae 70

Filamentous algae 70 Enteromor ha 40 < 1

Description: Patch cover of low growing Ruis beneath extensive free-floating al al mat.

14 u

Lough Gill 0

Site: Lough Gill Transect code: A 0 Location: Outlet to sea Sample point: 3 Marginal Sample area: 100m2 (10x10 Substrate:Silt Depth: 15 cm Salinit : 0arts per thousand G NVC communit : S21 Scir us maritimus swam- Scir us maritimus sub-community Height cm Cover Total Plant 100 0 Higher Plant 70

Scir us maritimus 80 70 0 Schoeno lectus lacustris sstabernaemontani 90 < 1 Phra mites australis 90 < 1

Algae 95 0 Enteromor ha 20 95

Description: Fairly dense Scir us maritimus swam with occasional Schoenolectus and 0 Phra mites shoots over a dense al al mat. Extending25m to stock fence. 0

Site-... Lough h Gill Transect code: A 0 Location: Outlet to sea Sample point: 4 Marginal Sam le area: 100m2 10x10 Substrate: Silt

Depth: 15 cm Salinit : 0arts per thousand 0 NVC communit :S21 Scir us maritimus swam- Scius maritimus sub-community Height cm Cover Total Plant 100 0 Higher Plant 60

Scir us maritimus 70 50 0 Schoeno lectus lacustris sstabernaemontani 80 10 Phra mites australis 70 < 1 0 Potamo eton ectinatus 6 5

Algae 80 0

Filamentous algae 80 0 Description: Increasingly open cover of dominant Scir us maritimus withSchoeno lectus increasingly frequent. Potamo eton ectinatus low growing and fairly sparse beneath G floating al al mat.Extending 15m landward of stock fence. Grazed. Backing to Irissuedacorus - Juncus effusus- A rostis stolonifera community, l 00m. 0 Grading to Ammo hila arenaria- Festuca rubra dune grassland.

0

15 Lough Gill

Site: Lough Gill Transect code: B

Location: Swam bordering shallow shelf Sample point: 1 Aquatic - 40m out Sample area: 25m2 (5x5 Substrate: Sand

Depth: 50 cm Salinit : 2arts p er thousand NVC communit :----- Height cm Cover %) Total Plant 30

Filamentous algae 20 Chara as era var. as era 6 20

Description: Open charo he cover beneath atch free-floating filamentous algae.

Site: Lough Gill ransectSali code: B Location: Swam bordering shallow shelf am leoint: 2 Aqua ic - 20m out Sample area: 25m2 5x5 ubstrate: Sand Depth: 30 cm Fnit : 2arts per thousand NVC communit :----- Height (cm) Cover Total Plant 50 Higher Plant 10

Zannichelliaalustris 5 10 Ruis maritima 6 < 5

Algae 40

Filamentous algae 20 Chara as era var. as era 6 20

Description: Chara as era dominant with high r plant associatesbeneat h patchy mat of filamentous algae.

16 U

Lough Gill 0

0 Site: Lough Gill Transect code: B Location: Swam bordering shallow shelf Sample point: 3 Aquatic - IOm out Sample area: 25m2 5x5 Substrate: Sand 0

Depth: 30 cm Salinit : 2arts per thousand NVC communit : 0 Height (cm) Cover Total Plant 60 Higher Plant 5 0

Zannichelliaalustris 5 < 5 Ruis maritima 8 < 5 0 Potamo eton ectinatus 8 < 5

Algae 60 0

Filamentous algae 60 0 Chara as era var. as era 5 10

0 Description: Chara as era dominant with higher plant associates beneath increasing cover of surface al al mat. 0

0

Site: Lough Gill Transect code: B 0 Location: Swam bordering shallow shelf Sample point: 4 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Sand

Depth: 30 cm Salinit : 2arts per thousand 0 NVC communit : ----- Height (cm) Cover Total Plant 90 0 Higher Plant 5

Zannichelliaalustris 5 5 0

Algae 90 0

Filamentous algae 90 0

Description: Sparse Zannichellia beneath extensive al al mat. 0

0

17 J

Lough Gill

Site: Lough Gill Transect code: B Location: Swam bordering shallow shelf Sample point: 5 Marginal Sample area: 100m2 10x10 Substrate:Silt

Depth.- 30 cm Salinit : 1 art per thousand NVC community.- S20 Schoenoplectus lacustrisssp tabernaemontani swamp - S.lacustris ssp tabernaemontani sub-community Height (cm) Cover (%) Total Plant 90 Higher Plant 75

Schoeno lectus lacustris sstabernaemontani 120 70 Phra mites australis 100 5 Potamo eton ectinatus 40 < 1

Algae 25

Filamentous algae 25 J

7 Description: Tall, fairly dense Schoeno lectus l acustrisswam with sparse Phra mites. v Patchal al mat with sparse Potamo etonectinatus. 40m.

J

Site: Lough Gill Transect code: B Location: Swam bordering shallow shelf Sample point: 6 Marginal Sample area: 100m2 (10x10) Substrate: Silt Depth- 0 - 20 cm J Salinit : 0arts per thousand NVC community: S20 Schoenoplectus lacustrisssp tabernaemontani swamp - S.lacustris ssp tabernaemontani sub-community Height (cm) Cover (%) Total Plant 90 Higher Plant 80

Schoeno lectus lacustris sstabernaemontani 120 70 Phra mites australis 100 < 1 Potamo eton natans 30 < 1 Lemna minor < 1

Algae 25

J Filamentous algae 25

Description: Tall, fairly dense Schoeno lectus lacustris J swam with sparse Phra mites. Patchalal mat with sparse Potamo eton natans and Lemna minor.20m. Grazed. Grading to Irissuedacorus- Juncus effusus - A rostis stolonifera community.

18 u

Lough Gill 0

0

Site: Lough Gill Transect code: C Location: Swam bordering deeper water Sample point:1 Aquatic - l Om out -grapnel 0 Sample area: Grapnel only Substrate:Silt (depth - 60cm +)

Depth:1 m Salinit : 2arts per thousand 0 NVC communit : ----- Height (cm) Cover (%) 0 M rio h llum s icatum Enteromor ha Filamentous algae 0

Description: 0

0

0 Site: Lough Gill Transect code: C Location: Swam bordering deeper water Sample point: 2 Aquatic - 2m out - grapnel Sample area: Grapnel only Substrate: Silt (depth - 60cm + 0 Depth:70 cm Salinit : 2arts per thousand NVC communit :----- Height (cm) Cover 0

Enteromor ha Filamentous algae 0

0 Descri tion:

0

0

0

0

0

0

19 0 J rl J Lough Gill

Site: Lough Gill Transect code: C Location: Swam bordering deeper water Sample point: 3 Marginal Sam le area: 100m2l 0x 10 Substrate: Silt

Depth: 5 - 70 cm Salinit : 1 art per thousand

NVC communit : S4 Phra mites australis swam- Phra mites australis sub-community Height cm Cover Total Plant 100 J Phra mites australis 240 100 Rumex h drola athum 70 < 1

Description- Tall dense Phra mites swam with sparse R. hdrola athum the only associated J species for 20m. Water depth decreasing rapidly from 70- 5cm within 3m of swam edge.

J Site: Lough Gill Transect code: C Location: Swam bordering deeper water J Sample point: 4 Marginal Sam le area: 100m2 (10x 10 Substrate: Silt

Depth: 5 cm Salinit : 0arts per thousand NVC communit :S4 Phra mites australis swam- sub-community undetermined Height cm Cover Total Plant 100

Phra mites australis 240 100 Angelica s lvestris 50 < 1 A ium nodiflorum 40 < 1 Potentillaalustris 40 < 1 Men anthes trifoliata 30 < 1 Lemna minor < 1

Description: Tall dense Phra mites bed with sp arse understoreof freshwater associates. Extending for c.200m. Backing to Lolium erenne- C nosaurus cristatus pasture.

J

20 u

Lough Gill 0

0

Site: Lough Gill Transect code: D 0 Location: Open shore Sample point: 1 Aquatic - 20m out- grapnel Sample area: Grapnel only Substrate-.Sand .

Depth.- 80 cm : Salinit 2arts per thousand 0 NVC communit : ----- Height cm Cover 0 M rio h llum s icatum Filamentous algae Chara as era var. as era 0

Descri tion: 0

0

C Site:Lough Gill Transect code: D Location: Open shore Sampleoint: 2 Aquatic- 10m out - grapnel Sample area: Grapnel only Substrate: Sand 0

Depth: 70 cm Salinit : 2arts per thousand NVC communit : Height cm Cover 0

M rio h llum s icatum Filamentous algae 0

0 Descri tion:

0

0

0

0

0

0 21 J

Lough Gill

Site: Lough Gill Transect code: D Location: Open shore Sample point: 3 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Sand,ravel, cobbles

Depth: 0 - 40 cm Salinit : 2arts per thousand NVC communit :----- Height cm Cover (%) Total Plant 100

Filamentous algae 100

Description: Water surface covered b free-floating al al mat fromshore to 5m out.

J

J

J

J

22 U

Lough Gill 0

0 Site: Lough Gill Transect code: D Location: Open shore Sample point: 4 Marginal 0 Sample area: !6m2 4x4) Substrate: Sandsoil

Depth: 0 cm Salinit : -----

NVC communit : Undetermined 0 Height (cm) Cover Total Plant 80 0 Irissuedacorus 100 40 A rostis stolonifera 15 25 0 Juncus articulatus 30 5 Potentilla anserina 8 5 Eleocharisalustris 25 5 0 Mentha a uatica 20 < 1 Nasturtium officinale 6 < 1 Fili endula ulmaria 50 < 1 0 H drocot le vul aris 2 < 1 Ranunculus acris 3 < 1 0 Polonum h dro ier 30 < 1 Rumex acetosa 8 < 1 Galium alustre 10 < 1 0 Juncus bufonius 10 < 1 Samolus valerandi 10 < 1 A ium nodiflorum 8 < 1 0 Stellaria alsine 15 < 1 Rumex con lomeratus 12 < 1 Calthaalustris 10 < 1 0 Leontodon autumnalis 20 < 1 Senecioalustris 15 < 1 a Potentillaalustris 5 < 1 Juncus effusus 45 < I 0 Description: Patch cover of Iris dominated community forming 4m widestrip along poached wet earth and sand bank, average slope c.30 degrees. Grazed.Man species fairly low growing. 0 Grading to Lolium erenne- C nosaurus cristatus pasture. 0

0

0

23 J M

J Lough Gill

Site: Lough Gill Transect code: E Location: Freshwater inflow Sample point: 1 Aquatic - 20m out Sample area: 25m2 5x5 Substrate: Sand Depth: 50 cm Salinit : 0arts per thousand

NVC communit : ----- Height (cm) Cover Total Plant 25 Higher Plant 20

Zannichelliaalustris 6 15 M rio h llum s icatum 30 5

20 J Algae Filamentous algae 20 J Enteromor ha 10 < 1

U Description: Zannichellia dominant among sparse submer ent species. Patch surfacelayer of filamentous algae.

Site: Lough Gill Transect code: E Location: Freshwater inflow Sample point: 2 Aquatic - 10m out Sample area: 25m2 5x5 Substrate: Sand and silt

Depth: 50 cm Salinit : 0arts per thousand NVC communit :----- Height (cm) Cover %) Total Plant 60 Higher Plant 40

Zannichelliaalustris 6 20 Ruis maritima 40 20

Algae 40

Filamentous algae 40 Enteromor ha 10 < 1

Description: Ruis and Zannichellia in mixed and single species patches, someRuppia plants in flower. Surface alal mat becoming more extensive but still patchy.

24 u

Lough Gill 0

0

Site: Lough Gill Transect code: E 0 Location: Freshwater inflow Sample oinc3 Aquatic- 3m out Sample area: 25m2 5x5 Substrate: Sand and silt Depth: 50 cm Salinit : 0arts p er thousand 0 NVC communit : ----- Height cm Cover Total Plant 30 0

Ruis maritima 40 25 Potamo eton ectinatus 40 5 0 M rio h llum s icatum 40 < 5 0 Description: Ruis dominant with sp arse associates. Some Ruis in fruit. No al al mat to c.5m out. a

0

a Site: Lough Gill Transect code: E Location: Freshwater inflow Sample point: 4 Marginal Sample area: 100m2 10x10 Substrate: Silt 0

Depth: 0 - 50 cm Salinit : 0arts per thousand NVC communit : S4 Phra mites australis swam- Phra mites australls sub-community 0 Hei ght (cm) Cover %) Total Plant 100 a Phra mites australis 200 100 Callitriche herma hroditica < 1 0

Description: Dense Phra mites swamp. 15m. Water dep th decreasinggradually. 0

0

0

0

0 25 0 Lough Gill

Site: Lough Gill Transect code: E Location: Freshwater inflow Sample point- 5 Marginal Sam le area: 100m2l 0x 10 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :S4 Phra mites australis swam - Galium alustre sub-community ri Height cm Cover %) LJ Total Plant 100

Phra mites australis 200 100 E uisetum fluviatile 100 5 Mentha a uatica 70 5 J A ium nodiflorum 20 5 Galium alustre 15 < 1 iJ Description :Dense species-poor Phra mites fen with sparse freshwater associates. c.100m. Grading to Lolium erenne- C nosaurus cristatus pasture.

Site: Lough Gill Transect code: F Location: Barrier Sample point:1 Aquatic - 10m out - grapnel Sample area: Grapnel only Substrate: Sand

Depth: 50 cm Salinit : 3 arts per thousand J NVC communit : ----- Height (cm) Cover

Filamentous algae 30 Chara as era var. as era

Description: Patchsurface cover of free-floating alal mat. Same species and alal mat cover from 10m out to marginal zone. 7 J

26 u

Lough Gill 0

0

Site: Lough Gill Transect code: F Location: Barrier Sample oint: 2 Marginal 0 Sample area: 100m2 10x10 Substrate: Sand and silt Depth: 50 cm Salinit : 3 arts per thousand 0

NVC communit : S21 Scir us maritimus swam - Scir us maritimus sub-community Height (cm) Cover %) Total Plant 50 0 Higher Plant 40

Scir us maritimus 100 25 0 Schoeno lectus lacustris sstabernaemontani 120 10 Phra mites australis 130 5 0

Algae 10 0 Filamentous algae 10 0 Description: Open Scir us maritimus dominated swam for 20m. Sparsecover of associated emer ents and surface al al layer. 0

E

0

0

0

C

0

0

0

0 27 n 7 Lough Gill lJ n JI ri J Site: Lough Gill Transect code: F Location: Barrier Sam leoint: 3 Marginal Sample area: 100m2 10x10 Substrate: Sand and silt

Depth: 40 cm Salinit : 3arts per thousand J NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover Total Plant 95 Hi her Plant 90

Phra mites australis 170 75 Schoeno lectus lacustris ss tabernaemontani 120 5 T ha latifolia 170 5 Scir us maritimus 100 < 1 N m haea alba 5 Baldellia ranunculoides 80 < 1

Algae 10

Filamentous algae 10

Description: Fairly dense Phra mites dominated swam with sparsecover of associated species ands arse surface mat of filamentous algae. 17m.

J

J

J n J

J n 28 u u

Lough Gill 0

E

Site: Lough Gill Transect code: F 0 Location: Barrier Sample point: 4 Marginal Sample area: 25m2 5x5 Substrate: Sand

Depth: 0 cm Salinit : ----- 0 NVC communit :Undetermined Height cm Cover Total Plant 100 0

Phra mites australis 150 20 0 A rostis stolonifera 30 75 Potentilla anserina 30 5 Juncus articulatus 70 5 0 Mentha a uatica 30 < 5 Fili endula ulmaria 130 < 5 Ranunculus acris 20 < 1 0 Calthaalustris 30 < 1 Angelica s lvestris 90 < 1 Heracleum s hond lium 100 < 1 0 Vicia cracca 80 < 1 E uisetum fluviatile 40 < 1 0 Description: Open Phra mites cover with dense A rostis dominantamongst fen vegetation, 5m Grading to improved meadow with Trifolium re pens, T.ratense, Bromus 0 hordeaceus, c.100m. Grading to Ammo hila arenaria- Festuca rubra dune grassland. 0

7.3.4Evaluation 0

'Potentially Valuable' 0 This large sandy site was surveyed by transects only. Therefore,the information available upon which to make this assessment is limited comparedto most other sites. Six transects were carried out. 0

Ruppia maritima was found growing in fairly dense patchesnear the freshwater 0 inflow, the outlet channel and the south east shore. Itis extensive around the outlet, growing in dense beds to 50 metres out from theshore. 0 Potamogeton pectinatus was found at the same three transects atmore or less sparse cover. Both species are seen to have a wide distributionacross the site. a

29 Lough Gill 7 J Locally abundant Zannichellia palustris grows with the last two speciesat the freshwater inflow and south eastern transect sites. Myriophyllum vpicalumwas found J at three places in the western half of the lagoon. Chara aspera var. aspera showed a wide distribution, occurring atthe south western, south eastern and north central transect sites.

There is a notable diversity of marginal species and communitieshere. Phragmites, Schoenoplectus and Scirpus maritimus all occur in fairly extensive mixedand single species swamps. Typha latifolia occurs with Phragmites along the northshore and Iris psuedacorus is locally dominant on the south eastern shore.Freshwater Phragmites fen can be found in the south east andassociated with the main freshwater inflow. Rumex hydrolapathum occurs in this community.

Lough Gill is representative of mildly brackish conditions. Aquatic species composition is interesting and distribution and abundance worthy of furtherstudy. Diversity of marginal communities is fairly high.

Full aquatic survey is recommended.

J

30 J Lough Gill

7.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

7.4.1 Site Description

Large coastal brackish lake with road-bridge sluice (Trench Bridge) andinlet channel, and extensive sand dune barrier. Most of lake shore with sandyand organic-rich margins. Vegetation dominated by Phragmites communis, with algalmats developing in areas.

Subsites (Fig 7.4. 1)

1. Phragmites communis (Q 614141) Phragmites communis with grasses, Mentha aquaticaetc., on organic soil between zone of J Phragmites in standing water and Iris pseudocoruswet pasture zone. Near shore water salinity low (2%0 on 15 ix 96).

2. Sandy shore with al al mat (Q 605144) c. 2m wide sandy beach uncovered by water with driedalgal mat covering most of sand, and Phragmites communis, Schoenoplectus lacustris, Typhasp. and Nymphaea alba in water. Dune herb-rich grassland above c. 0.3 m cliff from beach.Hirundinea (leeches) common under mat.

7.4.2Methods

Site Rating using Indicator Species

Species rarity or community typicalityare the most frequently used criteria for rating sites for their biological conservation value. The approach inthis Coleoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular,it is assumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or bioticresponses (algal growth, Scirpus monoculture) to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicatingthe presence of rare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selectedas indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitatassociated with the lagoon margins; and, (2) they are reported in the literatureas being local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

31 u

0

0

N 0

0

0

0

0

0

0

0

0

0

0

a

a

0

Fig. 7 4. 1 Map of sampling sites (Carabidae and Staphylinidae) at Lough Gill,Co Kerry

I- Pitfall traps, S-vac 0 2 - Pitfall traps, Ground search

U J

Lough Gill

Interpretation of Indicator Species

Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) J low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if there were less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings

The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based J on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy

At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on 7 coastal lagoons.

Sampling Techniques

The sampling methods used are listed in Table 7.4.1. Foreach site, a St1h1W BR 400 suction apparatus, mounted on the operator's back, was used. This machine (referred to hereafter as 'S-vac' to distinguish it from the'D-vac' suction sampler) has asuction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held

32 u Lough Gill 0

pipe was shaken when the apex of the pipewas in the vegetation, a larger area (c. 2 m2)was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- 0 freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these trapswere fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were 0 used for the traps themselves.

0

TABLE 7.4.1. Details of sampling methods. 0

0 Method Details No. replicates Sampling period, etc. per unit sample 0 Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and 0 plastic funnels; collars used where cattle/horses occur Cobble samples Cobbles turned 0.5- 2 in 30 0 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; 0 agitated soil floated. in water Ground search Search of bare soil (< 50% 1 1 hour 0 vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, suchas shingle cobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs,were also sampled if they occurred to 0 a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (I hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. 0 Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. Thiswas unavoidable, and due to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are 0 representative of the sites, even if spring speciesmay be absent.

Variety of sampling techniques a

Several techniques will always give a more robust picture ofthe fauna of a site, 0 because any weather- or site-affected bias inone technique will be compensated by other sampling methods. Some sites did notpossess suitable habitat (peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground searchor cobble search. This is 0 regarded as an absence of habitat, rather thanan unavailable sampling opportunity.

0 33 J Lough Gill

That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is J difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >1 m) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall trapswere placed varied from site to site. This is not regarded as biasing results toany great extent, however, as much of the trap sample appears to be obtained in the first twoweeks.

J Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens ofmany of the other species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conseri : Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera)were recorded from (1) Phragmites communis area- S-vac suction sampler (15 ix 1996), c. 2m2, (2) Phraginites communis area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (15 ix- 12 x 1996); (3) Sandy shore with algal mat- 6 pitfall traps (28 vii - 15 ix 1996); (4) Sandy shore with algal mat-1 h ground search under algal mat (28 vii 1996).

34 Lough Gill 0

0 Species were selected as indicators of conservation value if: (1)they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less 0 likely to survive in historically degraded ecosystems.

7.4.3Survey Results 0

Twenty one species of carabid and fifty-five species of staphylinidwere recorded, two species of which are regarded as indicator species (Table 7.4.2). 0

Gabrius keysianus is a halobiont coastal shore species (Koch 1989),widespread but local in England and Wales (Hyman and Parsons 1994), and generally localand mostly rare in western 0 Europe (Horion 1965). It has been previously recorded in Ireland(O'Mahony 1929). C Myllaena infuscata is generally local in Europe and occurs inmarshy meadows, ditches, alder carr, etc. (Horion 1967), rather than on lake shores. Whileit can be regarded as stenotopic (e.g. Koch 1989), it could occur inland of Lough Gill,and is not likely to be dependant on 0 shore habitats created by coastal processes. It has not thereforebeen selected as an indicator species. 0 Philonthus fumarius appears to be widespread but local in Ireland(Johnson and Halbert 1902, Lott and Bilton 1991) and Great Britain (Hyman and Parsons1994). It is not rare in Central Europe, but rather rare eslewhere (Horion 1965). The species occursin marshes including 0 muddy and marshy freshwater shores, but is not recorded ashalotolerant (Horion 1965, Koch 1989) and especially on coastal marshes (Hyman and Parsons 1994).It was also recorded during this survey from Kilkern Lake and Lough Tanai. 0

0

TABLE 7.4.2Carabidae and Staphylinidae (Coleoptera) recorded from Lough Gill. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), withthe 0 exception of Booth (1988) for Tachyporus dispar. a

Species No. individuals 0

Carabidae

.agonum inarginatiun (L.) 2 0

Agonum muelleri (Hbst.) I Agonum pelidnum (Payk.) 5

Amara ovata (F.) 1 0 Bentbidion lampros (Hbst) 2 Bembidion mannerheimi Sahlb. 46

Bembidion normannum Dej. I Beinhidion tetracolum Say 3 Carabusgranulatus L. 13

35 J

Lough Gill

TABLE 7.4.2 (cont.)

Demetrias atricapillus (L.) 7

Dromius hnearis (OI.) 1 Dyschirius globosus (Host.) 11

Dyschirius thoracicus (Rossi) 1 Harpalus rufipes (Geer) 29

Leistus terminatus (Hellw.) 1 J Nebria brevicollis (F.) 16 Pterostichus melanarius (Ill.) 4 Pterostichus minor (Gyll.) 6 Pterostichus niger (Schall.) 43 Pterostichus nigrita (Payk.) 65

Trichocellus placidus (Gyll.) 1

Staphylinidae

Acrotona aterrima (Grav.) 1

Aloeonota gregaria (Er.) 1

Amischa analis (Grav.) 1 Anotylus rugosus (F.) 13 Atheta amplicollis (Muls. Rey) 28 Atheta elientula (Er.) 7 Atheta elongatula (Grav.) 7 Atheta fungi (Grav.) 16 J Atheta graminicola (Grav.) 3

Atheta luteipes (Er.) 1 Atheta orbata (Er.) 3 J Atheta volans (Scriba) I Blediusgallicus (Grav.) 2 Carpelimus corticinus (Grav.) 17 Carpelimus elongatulus (Er.) 6 J Carpelimus rivularis (Motsch.) 5 Cordalia obscura (Grav.) 16 Gabrius keysianus Sharp 2 Indicator species Gabrius pennatus Sharp 4 Ischnopoda atra (Grav.) 3 Lathrobium brunnipes (F.) 2 J Lathrobium geminum Kr. 1 Lathrobium quadratum (Payk.) I Lesteva sicula Er. 8 Mveetoporus splendidus (Grav.) I J jkfyllaena dubia (Grav.) 7 .yllaena infuscata Kr. 4 Olophrum fuscum (Grav.) 8 Philonthus cognates (Steph.) 3 Philonthus faunarius (Grav.) 10 Indicator species Philonthus laminatus (Creutz.) 5

Philonthus micans (Gray.) 1 Philonthus quisquiliarius (Gyll.) 12 Ouedius fuliginosus (Gray.)

lcurtipennis Bernh. I

Rugilus erichsoni (Fauv.) 1

Sepedophilus nigripennis (Steph.) 1 .Staphvlinus dimidiaticornis Gemm. 1 .Stenus bimaculatus Gvll. 1 l Stenus br unnipes Steph. I Stenus cicindeloides (Schall.) 10

36 1 Li

Lough Gill 0

TABLE 7.4.2 (cont.) 0

Stenus clavicornis (Scop.) 1 Stenus formicetorum Mannh. 3 .Stenus fulvicornis Steph. I 0 Stenusjuno (Payk.) 8

Stenus melanopus (Marsh.) 1 .Stenus nitidiusculus Steph. 2 a Stenus pallitarsus Steph. I Stenus similis (Host.) 2 Tachinus signatus Grav. 2 Tachyporus dispar (Payk.) 7 0 Tachyporus obtusus (L.) 3 Tachyporus pallidus Sharp I Tachyporus pusillus Grav. 2 0 Tachyporus solutus Er. 2 Xantholinus longiventris Heer 4 0

7.4.4Evaluation 0 Of average conservation interest for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional] 0 Scientific Argument for Rating 0 The presence of two indicator species associated with coastal shoresindicates average conservation interest. 0

7.4.5References Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation 0 of 7. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Horion, A. (1965) Faunistik der Mitteleuropaischen Kafer. X. Staphylinidae: Paederinaebis Staphylininae. Feyel, Uberlingen-Bodensee. 0 Horion, A. (1967) Faunistik der Mitteleuropaischen Kafer. XI. Staphylinidae: Habrocerinae bis Aleocharinae (Ohne Subtribus Athetae). Feyel, Uberlingen-Bodensee. 0 Hyman, P. S. and Parsons, M. S, (1994) A reviewof the scarce and theatened Coleoptera of Great Britain. Part 2. UK Nature Conservation Series No. 12,Joint Committee for Nature Conservation, Peterborough. 0 Johnson. W.F. and Halbert, J.N. (1902) A list of thebeetles of Ireland. Proc. R. Ir. Acad. (3) 6: 535-827. Koch, K. (1989) Die Kafer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. 0 Lohse, G. A. and Lucht, W.H. (1989) Die Kafer Mitteleuropas.12. 1. Supplementband mil Katalogteil. Goecke & Evers, Krefeld. Lott, D.A. and Bilton, D.T. (1991) Records of Coleoptera fromIrish wetland sites in 1989. 0 Bull. Ir. biogeog. Soc. 14: 60-72. Lucht, W. H. (1987) Die Kafer Mitteleuropas. Katalog. Goecke &Evers, Krefeld. O'Mahony, E. (1929) Coleoptera. In: Praeger, R.L. (ed.) Report ofrecent additions to the Irish fauna and flora. Proc. R. Ir. Acad. 39(B): 22-36.

37 E Lough Gill

7.5 SUMMARY AND EVALUATION

Lough Gill is a large (160 ha.) natural sedimentary lagoonwith a sand barrier and therefore of international importance based on the Habitats Directive.

The lake lies within a proposed NHA (Site Code 2070).It is a Wildfowl Sanctuary and an SPA for birds, although peak waterfowl counts have declineddrastically since 1979. The dune area is of major importance as the mainbreeding site for the Natterjack Toad, Bufo calamita. J The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology High Aquatic Fauna Moderate Vegetation Potentially High Ecotonal Coleoptera Average

Geomorphology.

The lake is a shallow natural lagoon "in a classicalposition" (Guilcher & King 1961) lying between two sand barriers which unite to form atombolo connecting the mainland to a group of the Magharee Islands

On this basis it is rated as of High conservationvalue.

Aquatic Fauna

A total of 43 taxa and 35 species were recorded,but this list included only one species (Lekanesphaera hookeri) regarded as a lagoonal specialist. Most of the beetles were taken in light traps andcould have been attracted by the lights while flying. Some brackishwater species e.g. Lekanesphaera hookeri and Pomatoschistus microps were confined to the area near the mouthof the sea inlet while others e.g. Clitellio arenarius and Neomysis integer were morewidely distributed.

The fauna is rich and diverse, comprising both freshwater andbrackishwater elements. Hemiptera (6 spp.) and Coleoptera (11 spp.) were especially abundantand diverse. The faunal assemblage typifies a system which is essentially freshwaterbut which receives small incursions of seawater. All of the hemipterans andbeetles are freshwater

39 Lough Gill 0 species. The long, sluiced inlet and weir apparently prevent crabsand prawns entering the lake but juvenile flounder and mullet were able tofind their way in during 1996. 0 Cercyon sternalis is a new record for Ireland. This and four other beetles were not recorded at any other site during the survey. 0

The aquatic fauna appears to be diverse and includes onerare species but is typically freshwater. A significant brackish element is present but only onelagoonal specialist 0 was recorded. As a result of this, based on theinvertebrate fauna Lough Gill is rated only as of moderate conservation value as a coastal lagoon. 0 Vegetation

This large sandy site was surveyed by transects only. Therefore,the information 0 available upon which to make this assessment is limited comparedto most other sites.

Ruppia maritima was found growing in fairly dense patches nearthe freshwater 0 inflow, the outlet channel and the south east shore. Itis extensive around the outlet, growing in dense beds to 50 metres out from theshore. Potamogeton pectinatus was found at the same three transects at more or lesssparse cover. Both species are seen 0 to have a wide distribution across the site. Locally abundantZannichellia palustris grows with the last two species at the freshwater inflowand south eastern transect 0 sites. Myriophyllum spicatum was found at three places in thewestern half of the lagoon. Chara aspera var. aspera showed a wide distribution, occurringat the south western, south eastern and north central transect sites. 0 There is a notable diversity of marginal species and communitieshere. Phragmites, Schoenoplectus and Scirpus maritimus all occur in fairly extensive mixedand single 0 species swamps. Typha latifolia occurs with Phragmites along the northshore and Iris psuedacorus is locally dominant on the south eastern shore.Freshwater Phragmites fen can be found in the south east andassociated with the main freshwater a inflow. Rumex hydrolapathum occurs in this community.

Lough Gill is representative of mildly brackish conditions. Aquatic species 0 composition is interesting and distribution and abundance worthy of furtherstudy. Diversity of marginal communities is fairly high. 0 As a full aquatic survey was not possible Lough Gillis only rated as ";potentially valuable". A full aquatic survey is recommended. 0 Ecotonal Coleoptera

Twenty one species of carabid and fifty-five species of staphylinidwere recorded, two species of which are regarded as indicator species

Gabrius keysianus is a halobiont coastal shore species, widespread butlocal in England and Wales and generally local and mostly rare in western Europe. It has been previously recorded in Ireland (O'Mahony 1929).

39 Lough Gill

Myllaena it fuscata is generally local in Europe and occursin marshy meadows, ditches, alder carr, etc., rather than on lake shores. While it canbe regarded as stenotopic it could occur inland of Lough Gill, and is not likely to bedependent on shore habitats created by coastal processes. It has not therefore been selected as an indicatorspecies.

Philonthus fitmarius appears to be widespread but local in Irelandand Great Britain. It is not rare in Central Europe, but rather rare eslewhere.The species occurs in marshes including muddy and marshy freshwater shores, but is not recordedas halotolerant and especially on coastal marshes. It was also recorded during thissurvey from Kilkeran Lake and Lough Tanai.

The presence of two indicator species associated with coastal shoresindicates average conservation interest. Lough Gill is therefore rated as of averageconservation value for terrestrial ecotonal community.

Summary

The lake is an important trout fishery and of greatconcern to the local inhabitants as a local resource to encourage tourism.Recent algal blooms, presumably resulting from eutrophication have caused fish kills, and an apparent decline inwaterfowl numbers.

Geomorphologically it is a classic example of a lagoon lyingbetween two sedimentary barriers. However, the predominance of freshwater species among the aquaticfauna and the localised occurrence of the single lagoonal specialist nearto the sea inlet, casts some doubt upon the acceptance of the lake as atrue lagoon based on the fauna alone. Its conservation value as a coastal lagoon depends entirely onmanagement. If seawater was allowed to enter on a regular basis the lakewould merit more protection as a classic brackish lagoon The lake is a good example of a low salinity lagoon where a few brackishwater species coexist with a predominantly freshwater fauna and flora.

In conclusion, despite the paucity of lagoonal fauna and inconclusiveevidence based on vegetation, Lough Gill is rated of high conservation value mainly due to geomorphology.

Designation as a proposed SAC is recommended.

40 J

COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111) J

8. CLOONCONEEN POOL n J Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

J

Prepared for the National Parks and Wildlife Service

(BioMar/Life) 8. CLOONCONEEN POOL

CONTENTS

8.1 Study Area

8.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

8.2.1Methods 8.2.2Results 8.2.3Discussion ri 8.2.4Threats LJ 8.2.5Evaluation 8.2.6References

8.3 Vegetation Survey (Pat Hatch)

8.3.1Site Description 8.3.2Methods 8.3.3Results Shore based survey Transect tables 8.3.4Evaluation

8.4 Ecotonal Coleoptera (Jervis Good)

8.4.1 Site description 8.4.2Methods 8.4.3Results 8.4.4Evaluation J 8.4.5 References

8.5 Summary and Evaluation

J

J

J Cloonconeen Pool n 8. L.J CLOONCONEEN POOL, Co. Clare.

OS Grid Reference: Q 836 497, 1:50,000 Sheet No. 63 Alternative names: Rinevella Bay, Kilkredaun Pool (The pool isun-named on the 6" map.)

8.1 STUDY AREA

Generalfeatures Cloonconeen Pool is the name we have given toa partially cut peat bog which has become flooded by seawater. This pool lieson the north shore of the mouth of the Shannon estuary, just west of Kilkredaun Point, 2 km southwestof Carrigaholt (Fig. 8.1.1. A cobble barrier lies between the pool and thebeach which is over-topped during spring tides. Seepageareas can be seen along the landward side of thebarrier. Cloonconeen can be regardedas an unusual type of lagoon formed in peat. Thebarrier itself is transgressive and the peat exposedon the seaward side of the barrier has been eroded to reveal a drowned forest of pine,some 4,000 years old. Mitchell (1990) describes this as the finest example of "submerged forest'that he knows. Further offshore is another barrier of rock extending from bothsides of the bay with an opening in the middle, which possibly represents the position I of a former complete U barrier, enclosing a larger lagoon. Plate 8.2.5 shows thisouter rock barrier and the sea breaking over the inner cobble barrier (Plate 8.2.6) duringa storm in September 1996. The lagoon is small, and very little is known aboutit, except that the area to the east is an area for wildlife under the REP scheme. The lagoonand cobble barrier, together with the drowned forest, is of great geomorphological interest. J Climate and oceanographic influences

I (Climatic data are taken from Rohan 1986 and TheRoyal Irish Academy Atlas of Li Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompaniedby rain and strong winds. The mean daily air temperature is 6.5°C in Januaryand 15.5°C in July. The growing J season (the period of mean daily air temperatures above 6°C) is 10.5 months and as snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1100mm, and the number of rain days (1 mm ormore) is 175-200. Prevailing winds 7 are from the west. Mean annual hourly wind speeds are about 5.6 m/s and a maximum wind speed of 49m/s is estimated to occur once in 50 years. The daily duration of bright sunshine averages 3.5-4.0 hours.Relative humidity 7 is around 85% as on all Irish coasts. LJ Marine processes in the area are dominated by long periodAtlantic swell waves with ri median wave heights of 1.5-3.0 i in and frequent cyclonic depressions which produce U large waves, inshore breakers commonly exceeding8 m (Carter 1992). Maximum n wave heights (averaging once in 50 years) are 30-35 m(Couper 1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS)at Carrigaholt is 4.9 m (Admiralty Tide Li Tables). rl J

1 E

E

o,.ayCarrigaholt EJ °- Carraig an Chabhaltaigh Ca.r.gaholl New Ooay 4114 An Ce Noa

t I Carrrganolr PI ii nemackaderr/.slob EJ iwell /1N ((

EJ

0

EJ

8 .l E laoa

0

Kdconly Phi Pornre Chill Ch- 0 n u

E 45--

n u

c

u

/f r rt,, E Bade an BluOrinecinmytt n

LJ Fig. 8.1. 1Section of 150 000 neap showing locality of Cloonconeen Pool E J n Cloonconeen Pool J Landscape and Geology The lagoon lies in a small flat valley between areasof higher land to the east and west. The valley iscomprised mostly of peat which has been partially cut. The whole valley is subject to winterflooding from the sea, and is crossed by numerous drainage ditches, the largest of whichruns from the lagoon, under the road, to empty into the bay to theeast near Carrigaholt. According to local information, the peat in the area to the east ofthe road was cut during the last generation and this is partly the cause of serious flooding.Bedrock is described as J Namurian (R.I.A. 1979) Lake Topography The lagoon is approximately 200 m x 300 m andtotal area is 4- 5 ha during the dry periods but considerably more whenflooded. The lake is very shallow and appears to have a fairly uniform depth ofabout 80 cm over most of its area. The substrate is mostly unconsolidated peat with stones occurringalong the edge of the barrier and in washover fans.

Hydrology No large streams enter the lake but there are severalsmall drainage ditches, especially in the western part of the lake. Undoubtedlythere are groundwater discharges to the lake through the peat, butvery little is known about the water balance or ecology of coastal lagoons formed in peat. Seawaterenters by percolation through the barrier, apparently on most high tides, and overtoppingof the barrier appears to occur regularly on higher tides.

There is no daily tidal fluctuation in water level ofthe lake, but it is assumed that n levels rise during each spring tide, and during storms. Aseasonal pattern is likely, whereby water levels rise in the winter with the increasedrainfall, and gradually decline J to sometimes very low levels in the summer. Salinity and water quality Seawater at approximately 34 %o enters the lagoon and mixes with fresh groundwater discharges and direct rainfall butwe have no historical details of salinity levels. The valley is heavily grazed by cattle and the lagoonappears to be nutrient-rich, with dense growths of filamentous algae and soft organic substrate, butno precise details are available.

J

7 LJ

2 Cloonconeen Pool

8.2 AQUATIC FAUNA uI Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin

8.2.1Methods

Environmental variables A transverse profile of the barrier was drawn using heightsmeasured with a builders level and staff. Water depths were measured using a plumblinefrom an inflatable dinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site.

At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1%o precision). A photographic record was made of the site andlocal information sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which J glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations A and D inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

J Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons

3 u

Cloonconeen Pool C between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often with a different samplingmethod. The results of E the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present,common and abundant are G purely subjective, and absolute numbers vary between taxa. n Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of these werelarval or juvenile stages and difficulttoidentify with certainty. Some groups require adult males for identification and these were often not available due to low population density and the G limited number of individuals collected in the time available (e.g.Jaera, hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify whenpreserved (turbellarians, leeches). 0

All Diptera are identified to family level. 0 8.2.2Results 0 Cloonconeen Pool was sampled on 6.vii.96 during the first partof the survey, and from 9 to l0.viii.96 during the more intensive survey. C Four sampling stations were selected in the lagoon to reflectthe influences of substrate, vegetation and freshwater/seawater. Fig. 8.2.1 shows the location ofthe sample stations. D

Environmental variables Fig. 8.2.2 shows a profile of the barrier. E Station A (OS 8362 4966) was located at the southerncorner of the lagoon where the barrier is lowest and over-topping is frequent. In thisarea water depth varied from C 0 cm to 1 m, substrate was a mixture ofcobbles, gravel and coarse sand, and salinity measured 34%o. (Plate 8.2.2) 0 Station B (OS 8351 4976) was located in the northwestcorner of the lagoon, between the barrier and a small island. A drainage channel entersthe lagoon at this point and substrate was mostly fine silts and sand mixed with unconsolidatedpeat, depth varied 0 from 0 - 40 cm and salinity measured 30%0. Station C (OS 8382 4974) was located in the easterncorner of the lagoon, closest to the road (Plate 8.2. 1). Substrate consisted of soft unconsolidatedpeat and fine silt, 0 depth varied from 0-50 cm, and salinity measured 32%0. Station D (OS 8373 4981) was located in the northeasterncorner of the lagoon, depth 0 varied from 0-50 cm, substrate consisted of soft, unconsolidated peat,and salinity measured 32%0. Salinity at all sampling stations during this study periodwas only slightly lower than 0 that of seawater, but small isolated pools within 20 mof the lagoon registered salinities between 10 and 20%0. C

0 4 J

50

Mouth of the Shannon

49

83 84 J

Fig. 8.2.1 Location Map of Sampling Stations in Cloonconeen Pool, Co. Clare.

i 1 M. - 0 - - ofwater lagoon level Cobble barrier peat platform beach withdrowned forest O M. 100m Fig. 8.2.2 Profile of Barrier at Cloonconeen Pool, Co. Clare. 50m 0 C7 £3 C3 C3 C] C3 C3 C] C7 C3 C3 C3 C7 C7 C a o 0 0 J

Table 8.2.1. Fauna Recorded in Cloonconeen Pool. July and August1996.

------Sampling Stationsr-- ( L.T. = light-trap)

A L.T.A ! B L.T.B C L.T.C D I L.T.D Porifera - L- -' ---- J Cnidaria - - - Turbellaria

I I I -- I I -- Nemertea ------' - Annelids - - -- Crustacea ---! - - Ostracoda T Copepods j Cimpedia _ Mysidacea

Isopoda Lekanesphaera hookeri I a 50 a 50 a 150 a 120 Jaera nordmanni + _ + Amphipoda Gammarus locusta j + Orchestia gamrnarella + Tanaidacea J Decapoda Carcinus maenas + + j Palaemonetes varians a 55 a j 200 a 110 a j 56

Arachnids j Insects

Hemiptera Corixidae a 150 o j 2 a 50 a 40

Sigara stagnalis a a + + a +j a + Coleoptera Enochrus bicolor + + + + Odonata Plecoptera Trichoptera Ephemeroptera

+ + j + Diptera Chironomidae j Molluscs

Prosobranchia Hydrobiidae a ! c + Hydrobia ulvae 10

j J Hydrobia ventrosa l ! + Pulmonata Opisthobranchia

BivalviaCerastoderma glaucum a 1 shells cc a

Bryozoa ! Echinodennata 1 tJ Tunicata T 1

! F Teleostei Anguilla anguilla F. j

a ! c 16 Gasterosteus aculeatus ! 24 a -43 a 56

J

+ = present; o = occasional; c = common; a= abundant; F = fyke net U

Cloonconeen Pool 0

Fauna rJ The species recorded at the different stations, using all samplingmethods, are listed in Table 8.2.1.Among 14 taxa listed, 13 are identified to species. Thelist (excluding marginal species) comprises 2 marine species, 2 poly-mesohall ne, 7euryhaline, and one 0 oligo-mesohaline; no limnic species was recorded (Table 8.2.2). Six ofthe species are listed as a lagoonal specialists in Britain (Davidson et al.(1991). Salinity and substrate were similar throughout the pool and mostspecies were 0 recorded at all stations. However, Jaera ?nordmanni (females only andtherefore not positively identified) and Gammarus locusta, which live mainly under stones,were only present at station A where cobbles from the barrierwere present. Only eels and tJ sticklebacks were taken in fyke nets. A noteworthy feature of the pool was the abundance ofjuvenile Cerastoderma 0 glaucum Adults were searched for but none was found andshells were rare. 0

Table 8.2.2 Ecological categories of the recorded taxa in CloonconeenPool. L = lagoonal specialist according to Davidson et al. (1991). 0

Marine Gammarus locusta Hydrobia ulvae 0

Poly-mesohaline Hydrobia ventrosa L Cerastoderma glaucum L n Euryhaline Jaera nordmanni Lekanesphaera hookeri L Palaemonetes varians L G Carcinus inaenas Sigara stagnalis L Anguilla anguilla Gasterosteus aculeatus tJ

Oligo-mesohaline Enochrus bicolor L tJ Limnic None 0 8.2.3Discussion

The fauna was poor, reflecting the small size of thepool, the absence of emergent 0 vegetation and hard substrates, and a soft substrate which maybe unsuitable for most burrowing forms. The faunal assemblage typifies a lagoon without atidal inlet which receives frequent influxes of seawater which maintain a high salinity,but also receives tJ enough freshwater throughout the year for brackish conditions to persist.However, there may be periods when the salinity remains high fortoo long for some species and this may explain the absence of adult cockles. Nearly halfof the species recorded are 0 lagoonal specialists. a

0 5 n U Cloonconeen Pool

The abundance of the corixid Sigara stagnalis at such highsalinity (nowhere in the main body of the pool was the salinity <30%o oneither sampling occasion), is thought to be unusual.

None of the recorded species can be described as rarein Ireland.

8.2.4Threats

The area around the lake is grazed and the lagoonitself appears enriched. J The storm in September caused serious problems to the ownerby flooding the area so badly that cattle were washed onto the beach. There mustbe a serious threat of drainage unless the area could be in a REP scheme.Attempts to prevent the sea entering would, however, be costly and unlikely to be attempted.

8.2.5Evaluation

Cloonconeen Pool isnatural sedimentary lagoon with a cobble barrier on peat and J is therefore of international importance based purely on geomorphology.

Although small, and probably not originating entirely by natural processes,the pool is a true lagoon with a low cobble barrier which hasnot been modified by installation of a drainage pipe as is usually the case. It represents atype which may be unique to Ireland (and possibly Scotland) in that the substrate is composed almostentirely of peat which also underlies the barrier and extends onto the shore. Thepresence of an intertidal drowned forest, said to be the best coastal example inIreland, makes this site of special historical interest. The aquatic fauna is not diverse but is typical ofa brackish lagoon with a high salinity, and includes a high proportion of lagoonal specialists. The pool does not lie in or near a proposedNHA. The pool and shoreline are worthy of conservation for theirunusual geomorphology, the presence of the drowned forest, and the pool withits typical lagoonal fauna. Designation as a proposed SAC is recommended.

8.2.6References and Additional Sources of Information Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp.

6 u

Cloonconeen Pool 0

Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine 0 crustaceans. Journal of the marine biological Association of the United Kingdom 68:235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. 0 Hutchinson, C. 1979. Irelands wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. tJ 1, Bord Failte/ An Foras Forbartha. Mitchell, F. 1990. The Way That I Followed. Country House.271 pp.. 0 Moriarty, C.1975. The small fyke net as a sampling instrument ineel research. EIFA/T23 (Suppl. 1). 507-518.Poole, W.R. 1994. A population study ofthe European eel (Anguilla anguilla (L.))in the Burrishoole System, Ireland, with 0 special reference to growth and movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Ei Irish National Committee for Geography. Royal Irish Academy, Dublin 104 pp.

Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152. EJ

0

0

EJ

0

0

0

0

0

0

a

0

7 n IN

gI

go

0

as Plate 8.2. 1 View across eastern area of Cloonconeen Pool, Station C

J r a

IN

1. J

Plate 82.2View of seepage area in the barrier of Cloonconeen Pool,Station A do Plate 82.3 View of northwest area of Cloonconeen Pool, StationB

Plate 8 2.4View of "drowned forest" on the beach at Cloonconeen Pool_ 0

No

{

No rMR

It

Plate 82.5View of outer rock barrier at Cloonconeen Pool, looking toward Kllcredaun Pt.

r

Plate 8.2.6View of seawater overtopping the cobble barrier at Cloonconeen Pool, 0 during a storm in September 1996. r Cloonconeen Pool

8.3 VEGETATION SURVEY

J Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a way as to J facilitate its subsequent assessment and consideration for legal protection.

8.3.1Site Description(Fig. 8.3. 1)

A low-lying area with flat grazed wet grassland to thenorth, south and east. A wetland area extends away to the west with fairly extensivePhragmites and Spartina stands lying between the coast and drier pastoral farmland tothe north. This wetland is associated with the lagoon's main freshwater inflow, which flowsin at its western end. The sea lies beyond the shingle barrier to thesouth west with the remnants of a `drowned forest' on the shore below high water mark.

There are drainage channels to the north and east andsome evidence of small-scale peat cutting to south and east where Ruppia and Scirpusmaritimus occur in the resulting pools.

There are no extensive emergent stands. Scirpus formsa narrow fringe around much of the south and east shores and Phragmitesoccurs in one small area in the east and with saltmarsh species on the edge of the barrier.

Away from the stony barrier shore and the silty shoreassociated with the freshwater J inflow the remaining shores are of peat. Low cliffsoccur in places with shores of more shallow slope elsewhere.

7 8.3.2 Methods J Two survey methods were employed in thecourse of fieldwork: 1. Transects 7 2. Shore-based survey

1. Transects: I Ll The locality of these is shown in Fig. 8.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginalareas were sampled using quadrats or releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases,on the depth of soft substrates. A

8 0

0 Fig. 8.3.1 0

0

0

0

0

0

0

0

0

0

0

0

0 Do,M(nant Tff-ie5 codes: PhrajNaife5au.4rd15 PUU5 0 5mcir 5cirPuS wtgvi iv"L(5 - 5av Unyliccl 0 Saq - sq(icorrtid It wtd PNagr UGG1 vl -11- a wtari 0 N J TA -TE : Tra15ecf5 A - u =Polib change in Vegefdfion J n UI

rlI

U7

J

n J Fig. 83.2 Cloonconeen Pool, Co. Clare: Location of Transects and Shore-based Survey Sections U

Cloonconeen Pool 0 transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point. 0 One sample was taken at each aquatic sampling point alongthe transect.All plant species present in the sample area were recorded. The averageheight and percentage 0 cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover. 0 At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic E survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. 0 At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many 0 metres out from the shore. For the purposes of thissurvey, `the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and 0 the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, 0 high water mark, as this is difficult to establish atmany sites.

In the marginal areas through which each transect passed, homogeneousstands of 0 vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For E example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0 Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the transect. 0

Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) 0 methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentage cover(using the Domm scale) and the calculation of frequency for each species: 0

Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows:

Domin. 10 91-100% 9 76-90 % 8 51-75 % 7 34-50 %

9 Cloonconeen Pool J

6 26-3 3 J 5 11-25 4 4-10 3 <4 many individuals 2 <4 several individuals

1 <4 few individuals rl J Frequency Values n Frequency of each species within the total number of samplesis expressed as follows: t_J Frequency V 81-100 % IV 61-80 % J III 41-60 % n II 21-40 % I 1-20 % U rl Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. J Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are J presented in an appendix to this report. r1 Each aquatic and marginal transect sample is presented here intable form, with a brief J description covering dominant species, stand structure and physiognomy.

7 The locations of transects within each site were selected torepresent the degree of u variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of J course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal J communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps. r Aquatic vegetation was surveyed by use of the grapnel andby means of wading where

i L water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres

10 u

Cloonconeen Pool E out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes. a

A brief site description was written for each lagoon. 0 Constraints

Time. Restrictions on the time available in which to carryout this survey had the 0 following consequences: a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications 0 Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha '. E

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway n

Nomenclature c Scientific names of vascular plants in this reportare in accordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of 0 Britain and Ireland: Stoneworts' (1992).

Evaluation 0

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not 0 11 n J

Cloonconeen Pool

a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance isput on aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as J `Valuable', `Potentially Valuable' and `Not Valuable'.

A 'valuable 'site is one that is shown to beof particular interest and that is considered J to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest. J The fact that this is primarily a shore-based survey and 7 not a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic J survey of sites where recommended is to be encouraged.

8.3.3Results

L Shore-based survey

Section A-B

Aquatic: Ruppia maritima- sparse and low growing Filamentous algae- sparse

Sand and gravel substrate

Marginal:Sparsely vegetated shingle barrier. Tripluerospermum maritimum and Atriplex hastata dominant

Adjacent:Shingle barrier n Section B-C (Transect A) u Aquatic: Ruppia maritima- cover unchanged Filamentous algae rl - extensive surface layer to c. 15m out

I LJ Peat substrate

Marginal:Open Phragmites cover with Puccinellia maritima dominant belowover salt tolerant vegetation on peaty substrate. Juncus gerard" frequent. 5-12m

Adjacent:Unchanged

12 Cloonconeen Pool 0 Section C-D 0 Aquatic: Ruppia maritima- very sparse Filamentous algae- sparse 0 Marginal:Scirpus maritimus strip. lm Backing to Puccinellia maritima dominated saltmarsh community.As B-C but 0 now with sparse Scirpus cover replacing Phragmites. 12-15m Occasional small single species patches of Spartina along shore. Average area 4m2 0 Grading to Juncus gerardii- Festuca rubra saltmarsh community. c. 150m

Adjacent: Spartina anglica dominated vegetation. c. 100m 0 Phragmites australis bed. c. 100m C Section D-E

Aquatic: Unchanged E

Marginal:Spartina anglica single species stand forming 2-4m strip along shore 0 Backing to Juncus gerardii- Festuca rubra saltmarsh community with frequent Juncus maritimus tussocks as Transect B. c.150m 0

Adjacent:Unchanged 0

Section E-F (Transect B) 0

Aquatic: Filamentous algae- sparse 0 Silt substrate

C Marginal: Salicornia on open mud shore with occasional Spartina stands ofaverage area c.20m2. Salicornia sparse on lower shore,cover increasing to landward. 10-15m Backing to Puccinellia maritima dominated saltmarsh with patchy Agrostis n stolonifera and occasional Scirpus maritimus shoots. 10-15m Grading to Juncus gerardii - Festuca rubra saltmarsh community with C frequent Juncus maritimus tussocks. c.100m C Adjacent:Embankment with Rubus fruticosus and Salix cinerea Backing to public road Backing to Lolium perenne pasture G

G 13 n u Cloonconeen Pool

Section F-G

Aquatic: Unchanged

Marginal: Open muddy shore with sparse Scirpus maritimus and occasional Juncus maritimus tussocks and Spartina patches of c.6m2 maximum. Scirpus and Spartina heavily grazed. 15-20m J Grading to Puccinellia saltmarsh as E-F. Heavily poached and grazed.5- 8m n Grading to Juncus gerardii - Festuca rubra community as E-F

Adjacent:Unchanged

Section G-H (Transect Q

Aquatic: Ruppia maritima - sparse and low growing J Filamentous algae - dense and extensive

Marginal:Open cover of Juncus maritimus tussocks with patchy Juncus gerardiiand Agrostis stolonifera co-dominant below with salt tolerant associates. 3- 4m rl Grading to Juncus gerardii - Festuca rubra - Agrostis stolonifera J dominated community. c.100m. Poached and grazed

J Adjacent:Unchanged

J Section H-I

Aquatic: Unchanged

Marginal: I m peat cliff Backing to Juncus gerardii- Festuca rubra - Agrostis stolonifera community as G-H. J Adjacent:Unchanged Section I-J J Aquatic: Filamentous algae - dense and extensive 7 lJ Marginal:Occasional short stretches of peat cliff of c. 10m maximumextent Otherwise as G-H

Adjacent:Unchanged

14 Cloonconeen Pool 0 Section J-K 0 Aquatic: Ruppia maritima- sparse, low growing Filamentous algae- cover unchanged 0 Marginal:As G-H but with frequent Juncus maritimus tussocksover Juncus gerardii Festuca rubra - Agrostis stolonifera communityas Transect E 0 Adjacent:Unchanged 0

Section K-L (Transect D) 0 Aquatic: Unchanged

Marginal:Scirpus maritimus single species strip. 2m 0 Grading to open Scirpus cover with Juncus gerardii dominant belowin species- poor salt tolerant vegetation. 12m 0

Grading to Section L-M 0

0 Section L-M

Aquatic: Ruppia maritima -dense extensive beds 0 Filamentous algae -sparse

Marginal:Juncus maritimus dominant with occasional patches of Scirpus maritimus, 0 co-dominant in places. 4-5m

Grading to Section K-L n

Section M-N (Transect E) 0

Aquatic: Unchanged 0 Peat substrate 0 Marginal:Open Phragmites swamp withsparse Ruppia maritima. 3-5m Backing to dense cover of Juncus maritimus with frequent Phragmites shoots over species-poor salt tolerant vegetation. 4-5m a Grading to Juncus gerardii -Festuca rubra- Agrostis stolonifera saltmarsh community with open cover of Juncus maritimus. c.60m

Adjacent: Public road

0 15

P Cloonconeen Pool

Section N-O

Aquatic: Unchanged

J Marginal:As L-M Grading to Juncus gerardii - Festuca rubra - Agrostis stolonifera community as Transect C. c.100m

7 Adjacent:Lolium perenne pasture J Section O-P

Aquatic: Unchanged

Marginal: 1-1.5m peat cliff Backing to Juncus gerardii- Festuca rubra - Agrostis stolonifera community as Transect C. c.100m

Adjacent:Unchanged

Section P-O

J Aquatic: Unchanged

Marginal:Dense Juncus maritimus forming lm strip Grading as O-P

Adjacent:Unchanged

Section Q-R

LJ Aquatic: Ruppia maritima- Unchanged

Marginal:Scirpus maritimus single species stand forming 1-2m strip Grading as O-P

J Adjacent: Unchanged Section R-S

Aquatic: Ruppia maritima - sparse Filamentous algae- extensive

I LJ Marginal:As P-Q

Adjacent:Unchanged

16 n u U

Cloonconeen Pool 0

Section S-T 0 Aquatic: Unchanged

Marginal:As O-P 0

Adjacent:Unchanged 0 Section T-U

Aquatic: Unchanged 0

Marginal:Juncus maritimus and Scirpus maritimus each locally dominant in 1-2m strip 0 along shore. Occasional short stretches of 1-1.5m peat cliff Grading as O-P 0 Adjacent:Unchanged 0 Section U-A 0 Aquatic: Unchanged

Marginal:Scirpus maritimus dominant with species-poor salt tolerant understorey. 0 1-6m Grading as O-P 0 Adjacent:Unchanged 2. Transects 0 Site: Cloonconeen Pool Transect code: A

Location: Barrier 1 Sample point: Aquatic - 3m out 0 Sample area: 25m2 5x5 Substrate: Peat

Depth: 15 cm Salinit : 36arts per thousand NVC communit : ----- 0 Height (cm) Cover (%) Total Plant 100 Higher Plant < 1 0

Ruis maritima 20 < 1 a

Algae 100 0 Filamentous algae 100

Description: Very sparse Ruis amongst dense free-floating alal mat.

17 Cloonconeen Pool J

Site: Cloonconeen Pool Transect code: A Location: Barrier Sam leoint: 2 Marginal Sample area: 16m2 4x4 Substrate: Peat J Depth: 0 cm Salinit : ----- NVC community: S4 Phragmites australis swamp - Atriplex hastata sub-community- Puccinellia maritima variant Height (cm) Cover (%) Total Plant 100

Phra mites australis s0 30 Puccinellia maritima 20 90 Juncuserardii 25 20

Salicornia a . 20 5 Atri lex hastata 30 < 5 Aster tri olium 30 < 1 S erlaria marina 15 < 1 Tri lochin maritima 10 < 1 Cochlearia an lica 15 < 1 Glaux maritima 10 < 1 Planta o mantima 15 < 1 Atri lexatula 20 < 1

Descri tion: Open low growing Phra mites cover with saltmarshcommunit y below. Dense cover of dominant Puccinellia with patchy Juncuserardii and tall, sp arse salt tolerant associates. 12m. Backing shingle barrierravel, cobbles, boulders) with very s parse vegetation. Tri leuros ermum maritimum and Atri lex hastata most frewent with rare Glaucium flavum.

Site: Cloonconeen Pool Transect code: B

Location: S artina and Salicornia stands Sample point: 1 Aquatic - 3m out Sample area: 25m2 5x5 Substrate:Silt

Depth: 10 cm Salinit : 35arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 20

Filamentous algae 20

Description: Patch cover of free-floating filamentous algae only.

18 U

Cloonconeen Pool 0

0

0 Site: Cloonconeen Pool Transect code: B Location: S artina and Salicornia stands Sample point: 2 Marginal Sample area: 30m2 10x3 Substrate:Silt 0

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height (cm) Cover (%) 0 Total Plant 100

S artina an lica 100 0

0 Description: Dense single species stand of S artina. 3m

0

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a

0

Site: Cloonconeen Pool Transect code: B D Location: S artina and Salicornia stands Sample oint:3 Marg inal Sam le area: 100m2 10x10 Substrate: Mud

Depth: 0 cm Salinit : ----- 0

NVC communit : Undetermined Height (cm) Cover (%) Total Plant 25 0

Salicornia a . 10 25 S artina an lica 15 < 1 0

a Description: Open cover of dominant Salicornia with rare low growingS artina shoots. 12m. Salicornia cover varying from < 1% on lower shore toc.70% on upper shore. 0

0

19 J

Cloonconeen Pool

Site: Cloonconeen Pool Transect code: B Location: S artina and Salicornia stands Sample point: 4 Marginal Sample area: 16m2 4x4 Substrate. Mud

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover (%) Total Plant 100

Puccinellia maritima 10 80 A rostis stolonifera 10 25 Aster tri olium 35 10 Atri lex hastata 20 5 Cochlearia an lica 10 < 5 Scius maritimus 40 < 1 Salicornia agg. 15 < 1 Juncuserardii 30 < 1 Tri lochin maritima 15 < 1 S er ularia marina 20 < 1

Description: Dense cover of dominant Puccinel lia with sparse, fairlytall growing salt tolerant J species. A rostis stolonifera patchy and very locally co-dominant. 10m.

Site: Cloonconeen Pool Transect code: B Location: S artina and Salicornia stands Sample point: 5 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover (%) Total Plant 100

Juncus maritimus 80 25 Festuca rubra 20 75 Juncuserardii 25 25 A rostis stolonifera 15 10 Potentilla anserina 8 10 Aster tri olium 30 < 5 Leontodon autumnalis 20 < 1 Tri lochin maritima 15 < 1 Planta o maritima 10 < 1 Cochlearia an lica 6 < 1 Atri lex hastata 10 < 1

Description: Open cover of Juncus maritimus tussocks. Festuca rubra dominantbelow with Juncuserardii very locally co-dominant, A rostis stolonifera and Potentilla anserinapatchy. Otherspecies sparse. c.200m.

20 u

Cloonconeen Pool 0

0 Site: Cloonconeen Pool Transect code: C

Location: Marginal Juncus maritimus Sample point: 1 Aquatic - 3m out Sample area: 25m2 5x5) Substrate:Silt 0

Depth: 30 cm Salinit : 35arts per thousand

NVC communit : ----- Height (cm) Cover 0 Total Plant 100 Hi her Plant < 1 0

Ruis maritima 20 < 1 0 Algae 100

Filamentous algae 100 0

Description: Very sparse Ruis amongst dense free-floating filamentous algae. Olderarts 0 of Ruis plants coated balgae. Some plants in flower. a Site: Cloonconeen Pool Transect code: C Location: Marginal Juncus maritimus Sample point: 2 Marginal 0 Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : -----

NVC communit : Undetermined 0 Height (cm) Cover %) Total Plant 95 0 Juncus maritimus 80 30 Juncuserardii 15 40 a A rostis stolonifera 8 20 Aster tri olium 15 5 Tri lochin maritima 15 < 5 0 Glaux maritima 6 < 5 S er ularia marina 5 < 5 Atri lex hastata 20 < 1 0 Cochlearia an lica 5 < 1 Puccinellia maritima 10 < 1 Scir us maritimus 30 < I 0 Planta o maritima 15 < 1 Salicornia a . 6 < I 0 Description: Open cover of Juncus maritimus tussocks with salt tolerantvegetation dominated b patchy cover of Juncuserardii with A rostis stolonifera locally co-dominant. All other species sparse. Lightly poached,razed. 4m strialong shore. 0 Backing low eat bank (slope c.80 degrees,average height 50cm). G 21 J

Cloonconeen Pool

Site: Cloonconeen Pool Transect code: C Location: Marginal Juncus maritimus Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover Total Plant 100

Festuca rubra 15 75 A rostis stolonifera 10 60 Juncuserardii 15 20 Trifolium re pens 4 5 Potentilla anserina 3 5 Glaux maritima 4 < 5 Tri lochin maritima 10 < 1 Planta o maritima 10 < 1 Aster tri olium 10 < 1 Leontodon autumnalis 6 < 1 Cochlearia an lica 5 < 1 Atri lex hastata 10 < 1

Description-. Festuca rubra and A rostis stolonifera co-dominant with patchyJuncuserardii very locally so. Associated salt tolerant sp ecies more orless sparse and low growing.- Grazed. 100m. Backing 45 degree bank to c.2m height with Rubus fruticosusand Salix cinerea. Backing public road.

J 22 u

Cloonconeen Pool 0

0

Site: Coonconeen Transect code: D

Location: Scir us swam- sheltered bay Sample point: 1 Aquatic - 3m out 0 Sample area: 25m2 5x5 Substrate:Silt

Depth: 40 cm Salinit : 33arts per thousand NVC communit :----- 0 Height cm Cover %) Total Plant 100 0 Higher Plant < 1

Ruis maritima 30 < 1 0

Algae 100 0 Filamentous algae 100- 0 Description: Sparse Ruis amon st dense cover of free-floating filamentous algae. 0

0

0 Site, Cloonconeen Pool Transect code: D Location: Scir us swam- sheltered bay Sample point: 2 Marginal Sample area: 20m2 10x2 Substrate:Silt a

Depth: 0 cm Salinit : ----- NVC communit :S21 Scir us maritimus swam - Scir us maritimus sub-community a Height cm Cover (% Total Plant 75 0 Scir us maritimus 80 75

0 Description: Fairly dense Scir us maritimus single speciesswamp. 2m. 0

0

0

0 23

0 Cloonconeen Pool

Site: Cloonconeen Pool Transect code: D Location: Scir us swam - sheltered bay Sample oint:3 Marginal Sam le area: 100m2 10x10) Substrate: Peat

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover Total Plant 85

Scius maritimus 60 30 Juncus maritimus 80 5 Juncuserardii 40 40 Aster tri olium 40 20 Atri lex hastata 30 < I Cochlearia an lica 10 < 1

Description: Patch cover of Juncuserardii and low growing Scir us, each locally dominant over a few tall salt tolerant associates. Occasional Juncus maritimustussocks forming very open cover. Small bare patches of water-logged substrate. 12m.

Site: Cloonconeen Pool Transect code: E

Location: Phra mites swam & isolated pool Sample point: 1 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Peat

Depth: 20 cm Salinit : 34arts per thousand NVC communit :----- Height cm Cover Total Plant 100 Hi her Plant 70

Ruis maritima 40 70

Algae 100

Filamentous algae 100

Description: Substrate covere bfilamentous al gae with abundant Ruis growing through to the surface. Man Ruis plants in flower and fruit.

J 24 Cloonconeen Pool 0

Site: Cloonconeen Pool Transect code: E Location: Phra mites swam & isolated poolSample point: 2 Marginal 0 Sample area: 30m2 100- whole stand Substrate: Peat

Depth: 20 cm Salinit : 30arts per thousand NVC communit :S4 Phra mites australis swam- Phra mites australis sub-community 0 Height (cm) Cover (%) Total Plant 100 0 Higher Plant 5

Phra mites australis 70 5 0 Ruis maritima 40 < 1

Algae 100 0

Filamentous algae 100 0

Description: Sparse low growing Phra mites with dense cover ofsubmer ent filamentous 0 algae ands arse Ruis growing through. Only the few tallest Phra mites shootsin flower. 3m. 0

0

Site: Cloonconeen Pool Transect code: E Location: Phra mites swam & isolated poolSample point: 3 Marginal 0 Sample area: 40m2 10x4- whole stand) Substrate: Peat Depth: 0 cm Salinit : ----- a NVC communit :Undetermined Height (cm) Cover (%) Total Plant 100 0

Juncus maritimus 90 90 Phra mites australis 90 5 0 Aster tri olium 60 5 Glaux maritima 30 < 5 0 Atri lex hastata 40 < 5 A rostis stolonifera 30 < 1 Planta o maritima 25 < 1 0 Cochlearia an lica 10 < 1

0 Description- Dense cover of Juncus maritimus tussocks withsparse salt tolerant species including low growing Phra mites shoots. 4m. 0

0 25 0 J

J Cloonconeen Pool

Site: Cloonconeen Pool Transect code: E Location: Phra mites swam & isolated poolSample point: 4 Marginal Sample area: 16m2 4x4 Substrate: Peat Depth: 0 cm Salinity ----- NVC communit :Undetermined Height (cm) Cover %) Total Plant 100

Juncus maritimus 100 40 Festuca rubra 60 80 A rostis stolonifera 40 5 Juncuserardii 20 5 Potentilla anserina 30 5 Atri lex hastata 40 < 1 Glaux maritima 30 < 1 Aster triolium 50 < 1 Cochlearia an lica 15 < 1 Planta o maritima 30 < 1

Description: Open cover of frequent Juncus maritimus tussocks with Festucarubra dominant amongst tall growing salt tolerant species. A rostis, Potentilla andJuncuserardii all patchy in cover and very locally co-dominant. 12m.

Site: Cloonconeen Pool Transect code: E Location: Phra mites swam & isolated pool Sample point: 5 Marginal - Pool Sample area: 20m2 10x2 Substrate: Peat

Depth: 0 - 30cm Salinit : 15arts per thousand

NVC communit : S21 Scir us maritimus swam- Atri lex hastata sub-community Height (cm) Cover (%) Total Plant 95

Scir us maritimus 130 90 Atri lex hastata 20 5

Description: Tall dense Scir us maritimus swam with sparse Atrilex the only associated species. 2m.

J

J

26 u

Cloonconeen Pool 0

Site: Cloonconeen Pool Transect code: E 0 Location: Phra mites swam & isolated poolSample point: 6 Marginal - Pool Sample area: 125m2 25x5 - whole stand Substrate: Peat Depth: 30 cm Salinit : 15arts per thousand 0 NVC communit :----- Height cm) Cover Total Plant 100 0 Higher Plant 70

Ruis maritima 40 70 0

Algae 100 0 Filamentous algae 100 0

Description: Dense extensive patches of Ruis growing through filamentous algae in isolated pool 25x5m. Both flowering and fruiting Ruis plantsresent. 0 Backing 50cm eat cliff.

0

0 Site: Cloonconeen Pool Transect code: E Location: Phra mites swam & isolated poolSample point: 7 Marginal 0 Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :Undetermined 0 Height cm Cover (%) Total Plant 0 Juncus maritimus 90 5 Festuca rubra 20 50 0 A rostis stolonifera 20 40 Juncuserardii 20 20 Potentilla anserma 15 5 0 Atri lex hastata 20 < 1 Glaux mantima 15 < 1 Aster tri olium 25 < I 0 Leontodon autumnalis 20 < I Cochlearia an lica 6 < 1 0 Description: Sparse cover of Juncus maritimus tussocks. Festuca and Arostis co-dominant below with patchy Juncuserardii locally so. Associated salt tolerant species all more orless sparse. 50m. Backing to public road. 0 27 n J

J Cloonconeen Pool

8.3.4 Evaluation

`Not Valuable'

This is a small peaty lagoon of high salinity attime of survey (33 -36 parts per thousand).

Ruppia maritima was the only aquatic higher plant species. Itis more or less sparse but frequent around most shores and forms fairly dense bedsin the south eastern bay. It has a wide distribution, but is absent from thevicinity of the inflow channel.

Marginal communities and species show some diversity. Scirpus maritimus andJuncus maritimus are the dominant species around most shores, typically associatedwith a sparse understorey of salt tolerant species and grading to Juncus gerardii- Festuca rubra saltmarsh.

Puccinellia maritima saltmarsh occurs at the western end, including onestand on the barrier shore with an open Phragmites cover. Spartina anglica islocally dominant on the north western shore and there is one small areaof open Salicornia cover on a muddy shore in the same area.

Extensive stands of Phragmites and Spartina lie to the westof the site, associated with the inflow channel which joins the lagoon at its westernend.

This seems to be a particularly species-poor lagoon.

Further survey is not recommended.

J

rl

29 J Cloonconeen Pool

8.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES Terrascope Environmental Consultancy, Riverstick, Co. Cork

8.4.1 Site Description

Small coastal lagoon formed by sea flooding partially cut peatbog, with percolation through, and spring tide overtopping of, shingle barrier on eroded peatshore with exposed c. 4000 year-old pine stumps (Plates 1-3). Salt-marsh vegetation on peat; watersalinity c. 30 %o.

I L) Subsites (Fig. 8.4. 1) n J 1. Festuca rubra(Q 834496) Plate 4 Approx. 1 ha salt-marsh vegetation (Festuca rubra, Juncusspp, Aster tripolium, Plantago maritima, etc.) on peat (Plate 5), saturated at surface afterspring tides. Ungrazed, with peat islands, but main area separated from surrounding grazed vegetation andcattle pasture by channels. Includes occasional peat cuttings isolated from the lagoon marginwith c. lm high cliff walls, flooded at spring tide.

2. Overtoppininlet (Q 835495) Plate 6 Small (c. 250 m2) tongue of cobbles and coarse sandbehind barrier with extensive algal growth near water margin, and surface deposits of seaweed debris. n J 3. Phraites (Q 835495) Small area (c. 0.1 ha) behind barrier with moderately sparseregenerating Phragnrites n communes with Festuca rubra, Aster tripolium, Salicorniasp, etc., on peat, ungrazed.

8.4.2Methods n J Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or biotic responses (algal growth, .Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating thepresence of rare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

29 0

0

0

0

a

0

0

0

0

D

0

0

Fig. 8.4. 1Map of sampling sites (Carabidae and Staphylinidae) at Cloonconeen Pool,Co. Clare.

I- Pitfall traps, Cobble search 2 - Ground search 3 - Pitfall traps, S-vac 0 4 - Flotation 0

0 J Cloonconeen Pool J Therefore, species were selected as indicators of conservation value if: (1) they have a 7 restricted habitat preference to a specific type.of microhabitat associated withthe lagoon LJ margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems. J Interpretation of Indicator Species

Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a J categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings

The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ J significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy r1 At each site representative marginal areas were sampled, including vegetationdominated by LJ Scirpus maritimus, Juncus maritimus, Juncus gerardi andgrasses, as well as bare or poorly- vegetated areas of sand, silt or peat. Particular emphasiswas given to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons. U

30

1 U

Cloonconeen Pool 0

Sampling Techniques C The sampling methods used are listed in Table 8.4.1. Foreach site, a StihlW BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter G (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held 0 pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species 0 expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 0

0 TABLE 8.4.1. Details of sampling methods. 0

Method Details No. replicates Sampling period, etc. a per unit sample

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 n Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and plastic funnels; collars used a where cattle/horses occur Cobble samples Cobbles turned 0.5 - 2 in 30 from water margin 0 Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; 0 agitated soil floated in water

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during E warm weather without rain n Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (I hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent.

31 Cloonconeen Pool

Variety of sampling techniques

Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare 7 sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is J regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps

Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling

The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. n The priority for sampling therefore was to visit sites inresponse to dry weather j forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks. n u Quality control: identification

Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References

Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshiv. Ecosyst. 2: 185-208. Good, J. A. and Speight, M.C. D. (1991) Sites ofinternational and national importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 14: 48-53. J

J 32 Cloonconeen Pool 0

Methods used at this site E Carabidae and Staphylinidae (Coleoptera) were recorded from : Festuca rubra area- S-vac suction sampler (4 ix 1996), c. 2 m2; G Fe.stztca rubra area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (4 - 21 ix 1996), Flotation sampling of peat cliffs of peat cutting (24 subsamplesof 5 x 5 x 10 cm, 21 vii 0 1996); Overtopping inlet - cobble search (30 cobbles, 21 vii 1996); Phragmites area - 6 plastic pitfall traps with funnels andethylene glycol 0 preservative (4 - 21 ix 1996).

Species were selected as indicators of conservation value if: (1)they have a restricted habitat C preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. C

8.4.3Results E

Five species of carabid and five species of staphylinid wererecorded, two species of which are regarded as indicator species (Table 8.4.2). G

C TABLE 8.4.2. Carabidae and Staphylinidae (Coleoptera) recorded from Cloonconeen Pool. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0

0 Species No. individuals

Carabidae G

Befnbidion aeneum Germ. 2 Indicator species Benzbidion assimileGyll. I D Beinbidion minimum(F.) 3 Bembidion varium(Ol.) 5 Pterostichus niger (Schall.) I D

Staphylinidae G Brundinia meridionalis (Muls. Rey) 22 Indicator species Ocvpus ater (Grav.) 7 Philonthus rnarginatus (Strom) 2 E PoNstanota grisea (Kr.) I .Stenus canaliculatus Gyll. 3 0

0 33 n J

Cloonconeen Pool

Bembidion aeneum is a stenotopic halobiont species, occurring in thesalt spray zone above the upper shore and near brackish pools (Koch 1989). Althoughit is not listed as rare or notable in Great Britain (Hyman and Parsons 1992), and islisted as Irish without annotation by Speight et al. (1982), it is local in Britain and J Ireland according to Lindroth (1974). Brundinia meridionalis occurred in all samples, and was the mostabundant species recorded. It has not been previously recorded from Ireland. Although itis not listed in Hyman and Parsons (1994) as rare or notable in Great Britain, itappears to be rare or local in many parts of Europe (Porta 1926, Palm 1970, Benick & Lohse 1974,Mahler 1987, Koch 1989). B. meridionalis is a halophilous species, recorded from tidal refuse andsilty soils on the coast and also on inland saline soils in and other countries(Steel 1970, Koch 1989). Tidally undisturbed lagoons with stagnant water are favoured by this species- relatively large populations were recorded on organic-rich soils with dense algal growthat three lagoons in this survey (also at Bridge Lough and Lough Murree), butnot at other sites.

Although the staphylinid assemblage recorded from the Festuca rubra areahad low numbers of species, most of these were halophilous or occur insea shore habitats (Table 8.4.3). Of the five carabid species (Table 1), three Bembidion are halophilous, andanother (Bembidion assimile) is stenotopic, occurring in marshy shores and flooded meadows(Koch 1989).

TABLE 8.4.3.Staphylinid assemblage from Festuca rubra area, Cloonconeen Pool (S-vac suction sample and pitfall traps combined). Abund. Cat. refers tocategory of relative abundance (no. individuals: 1, 2-10, 11+).

Abund. Cat. Species No. Main biotope

Dominant Brundinia meridionalis 22 Halophilous, coastal

Intermediate Ocypus ater 7 Eurytopic, incl. sea shores Philonthus marginatus 2 Grassland (cattle dung) Stenus canaliculatus 3 Eurytopic, incl, muddy sea shores

Present PoNstomota grisea I Halobiont

8.4.4 Evaluation

Of average conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating The presence of two indicator species indicates conservation value, especiallywhen the tJ following are also considered: (1) the majority of the non-indicatorspecies are halophilous or breed in sea-shore habitats; (2) regularly salt-saturated peat is adifficult habitat for terrestrial soil insects, so few non-specialised species would be expected tooccur; (3) the site is small

34 u

Cloonconeen Pool a and, unlike other peat sites in this survey, is notconnected to peatland, but to marine littoral 0 and pasture biotopes, so peatland species are likely to beinfrequent. This indicates that the site is an ecologically well-developed example of isolated salt-inundated peat, andits conservation value depends on whether such sites are threatened in Ireland.The upper zone of isolated peat 0 in tidal salt-marsh may provide different physico-chemical soil conditions, becauseof regular tidal cycles. 0 8.4.5 References 0 Benick, G. and Lohse, G.A. (1974) Staphylinidae II (Aleocharinae, Callicerini).In: Freude, H., Harde, K.W. and Lohse, G.A. (eds). Die Kafer Mitteleuropas.5. Goecke & Evers, Krefeld. pp. 72-220. C Hyman, P. S. and Parsons, M.S. (1992) A review ofthe scarce and theatened Coleoptera of Great Britain. Part 1. UK Nature Conservation Series No. 3,Joint Committee for Nature Conservation, Peterborough. 0 Hyman, P. S. and Parsons, M.S. (1994) A review ofthe scarce and theatened Coleoptera of Great Britain. Part 2. UK Nature Conservation Series No. 12,Joint Committee for Nature Conservation, Peterborough. 0 Koch, K. (1989) Die Kafer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lindroth, C. H. (1974) Coleoptera, Carabidae. Hanbks Ident. Br. Insects4(2): 1-148. 0 Lohse, G.A. and Lucht, W.H. (1989) Die Kafer Mitteleuropas. 12.1. Supplementband mit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die Kafer Mitteleuropas. Katalog. Goecke & Evers,Krefeld. C Mahler, V. (1987) Sjette tillaeg til "Fortegnelse over Danmarks biller"(Coleoptera). Ent. Meddr. 54: 181-235. Palm, T. (1970) Skalbaggar, Coleoptera. Kortvingar: Staphylinidae. Underfam. Aleocharmae 0 (Atheta). Svensk Insektfauna no. 52: 117-296. Porta, A. (1926) Fauna Coleopterorum Italica. II. Staphylinoidea. Piacenza. Speight, M.C.D., Anderson, R. and Luff, M.L. (1982) An annotatedlist of the Irish ground 0 beetles (Col., Carabidae + Cicindelidae). Bull. Ir. biogeog. Soc. 6:25-53. Steel, W.O. (1953) The entomology of Spurn Peninsula. IX. Coleoptera,Staphylinidae. Naturalist 1952: 173-176; 1953: 125-129. D

0

0

0

E

0

0

35 Lr)

17 It 1 9 1 W -v w 1 9-1 r. I U-1 " T 1 t -/ U-1 q, ) /-7 u I w 1 [ 7 u Ir-i U-1 f l r

Cloonconeen Pool 6

go r

Plate 3 Exposed old pine stumps at Cloonconeen Pool, Co. Clare

IN

M

0

EN Plate 4 Subsite 1 - Festucarubra area at Cloonconeen Pool, Co. Clare r Cloonconeen Pool 7 I

Plate _5 Salt marsh vegetation on peat at Cloonconeen Pool, Co. Clare

0

0 Plate 6 Subsite 2 - overtopping inlet at Cloonconeen Pool, Co. Clare Cloonconeen Pool

8.5 SUMMARY AND EVALUATION

Cloonconeen Pool is small (4-5 ha.) but is a naturalsedimentary lagoon with a cobble barrier on peat and is therefore of international importancebased on the Habitats Directive.

Very little is known about this lagoon and it doesnot lie in or near a proposed NHA. J The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology Exceptional Aquatic Fauna High Vegetation No Value Ecotonal Coleoptera Average

Geomorphology. Although small, and probably originating partly from peat-cutting, the poolis a true lagoon with a low cobble barrier which has not beenmodified by installation of a drainage pipe as is usually the case. The cobble barrier is over-topped during spring tides and seepageareas can be seen along the landward side of the barrier. Cloonconeen can beregarded as an unusual type of lagoon formed in peat. The barrier itself istransgressive and the peat exposed on the seaward side of the barrier has been erodedto reveal a drowned forest of pine, some 4,000 years old which Mitchell (1990) describes as thefinest example of coastal "submerged forest' that he knows. It represents a type which may be unique to Ireland(and possibly Scotland) in that the substrate is composed almost entirely of peat which also underliesthe barrier and extends onto the shore. The lagoon and barrier, together with the drowned forest isregarded as of exceptional conservation value.

Aquatic Fauna

A total of 14 taxa was recorded: 13 are identifiedto species, of which six are listed as a lagoonal specialists in Britain (Lady's Island had only 8lagoonal specialists and is 100 times larger !)

36 u

Cloonconeen Pool 0

Salinity and substrate were similar throughout the pool and mostspecies were recorded at all stations. However, Jaera ?nordmanni (females only andtherefore not 0 positively identified) and Gammarus locusta, which live mainly under stones,were only present at station A where cobbles from the barrierwere present. 0 A noteworthy feature of the pool was the abundance ofjuvenile Cerastoderma glaucum. Adults were searched for but none was found andshells were rare. The aquatic fauna is not diverse but is typical ofa brackish lagoon with a high salinity, 0 and includes a high proportion of lagoonal specialists. The lagoon is rated as of high conservation value forthe high number of lagoonal E specialists in relation to the size of the pool. 0 Vegetation

Ruppia maritima was the only aquatic higher plant species.It is more or less sparse C but frequent around most shores and forms fairly dense bedsin the south eastern bay. It has a wide distribution, but is absent from thevicinity of the inflow channel. 0 Marginal communities and species show some diversity. Scirpus maritimus and Juncus maritimus are the dominant species around most shores, typicallyassociated 0 with a sparse understorey of salt tolerant species and gradingto Juncus gerardii - Festuca rubra saltmarsh. 0 Puccinellia maritima saltmarsh occurs at the western end, including onestand on the barrier shore with an open Phragmites cover. Spartina anglica islocally dominant on the north western shore and there is one small areaof open Salicornia cover on a 0 muddy shore in the same area.

Extensive stands of Phragmites and Spartina lie to the westof the site, associated with 0 the inflow channel which joins the lagoon at its westernend.

This seems to be a particularly species-poor lagoon and ratedas of no conservation n value. r, Further survey is not recommended.

Ecotonal Coleoptera 0

Five species of carabid and five species of staphylinid wererecorded, two species of which are 0 regarded as indicator species

Bembidion aeneum is a stenotopic halobiont species, occurring in thesalt spray zone above the 0 upper shore and near brackish pools. Although it is notlisted as rare or notable in Great Britain, and is listed as Irish without annotation by Speightet al. (1982), it is local in Britain 0 and Ireland according to Lindroth (1974).

C

37 n J

Cloonconeen Pool

Brundinia meridionalis occurred in all samples, and was the mostabundant species recorded. It has not been previously recorded from Ireland. Although itis not listed as rare or notable in Great Britain, it appears to be rare or local inmany parts of Europe. This species is an halophilous species, recorded from tidal refuse and silty soils onthe coast and also on inland saline soils in Austria and other countries. Tidally undisturbed lagoonswith stagnant water are favoured by this species - relatively large populations were recordedon organic-rich soils with dense algal growth at three lagoons in this survey (alsoat Bridge Lough and Lough Murree), but not at other sites.

Although the staphylinid assemblage recorded from the Festuca rubra areahad low numbers of species, most of these were halophilous or occurin sea shore habitats. Of the five carabid species, three Bembidion are halophilous, and another(Bembidion assimile) is stenotopic, occurring in marshy shores and flooded meadows.

The presence of two indicator species indicates conservation value, especiallywhen the following are also considered: (1) the majority of the non-indicatorspecies are halophilous or breed in sea-shore habitats; (2) regularly salt-saturated peatis a difficult habitat for terrestrial soil insects, so few non-specialised species wouldbe expected to occur; (3) the site is small and, unlike other peatsites in this survey, is not connected to peatland, but to marine littoral and pasture biotopes, sopeatland species are likely to be infrequent. This indicates that the site is anecologically well-developed example of isolated salt-inundated peat, and its conservation value depends onwhether such sites are threatened in Ireland. The upper zone of isolatedpeat in tidal salt-marsh may provide different physico-chemical soil conditions, because of regular tidal cycles.

As a result of the above, the site is ratedas of avera e conservation value for terrestrial ecotonal community.

Summary

Very little is known about this lagoon. There appear tobe no previous studies and very little disturbance to the site other than that caused bycattle-grazing. J The pool and shoreline are worthy of conservation for theirunusual geomorphology, the presence of the drowned forest, the pool with itstypical lagoonal fauna and the presence of a rare species of beetle, found in abundance.

In conclusion, although small, Cloonconeen is rated as of high conservation value based on geomorphology and fauna. rl Designation as a proposed SAC is recommended J

J

38 COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

9. LOUGH DONNELL

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

J

Prepared for the National Parks and Wildlife Service

(BioMar/Life) 9. LOUGH DONNELL

CONTENTS

9.1 Study Area

9.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

9.2.1Methods 9.2.2Results 9.2.3Discussion 9.2.4Threats 9.2.5Evaluation 9.2.6References

9.3 Vegetation Survey (Pat Hatch)

9.3.1Site Description 9.3.2Methods 9.3.3Results Shore based survey Transect tables 9.3.4Evaluation

9.4 Ecotonal Coleoptera (Jervis Good)

9.4.1Site description 9.4.2Methods 9.4.3Results 9.4.4Evaluation 9.4.5 References

9.5 Summary and Evaluation

J Lough Donnell

9. LOUGH DONNELL, Co. Clare.

OS Grid Reference: R 002 707, 1:50,000 SheetNo. 57 Alternative names: ?

9.1 Study Area General features

Lough Donnell is situated on the Atlantic coast of CountyClare, 4 km south of Quilty (Fig. 9.1.1). This shallow lagoon is impounded byan impressive cobble barrier, approximately 7 metres high and 40 metres wide. A smallriver, the Annageeragh River, enters the lagoon in the east anda pipe has been constructed through the barrier to prevent excessive flooding of the surrounding agricultural land. The lagoon is an ASI anda proposed NHA (site code 01018) largely due to its ornithological value. No large numbers of wildfowlare recorded but it is mentioned by Sheppard (1993) as being of major interest forwaders.

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and TheRoyal Irish Academy Atlas of Ireland 1979)

The region experiences a mild oceanic climatewith a small annual temperaturerange of only 8°C and frequent cyclonic depressionsaccompanied by rain and strong winds. J The mean daily air temperature is 6.5°C inJanuary and 15.5°C in July. The growing season (the period of mean daily air temperatures above 6°C) is 10.5 months andas snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1100mm, and the number of rain days (1 mm ormore) is 175-200. Winds are mainly from thewest and southwest. Mean annual hourly wind speeds are about 5.6 m/s anda maximum wind speed of 49 /s is estimated tooccur once in 50 years. The daily duration of bright sunshineaverages 3.5-4.0 hours. Relative humidity is around 85%as on all Irish coasts. Marine processes in the areaare dominated by long period Atlantic swell waves with median wave heights of 1.5-3.0in and frequent cyclonic depressions which produce large waves, inshore breakers commonlyexceeding 8 m (Carter 1992). Maximum wave heights (averaging once in 50 years)are 30-35 m (Couper 1983). Tides are semi- diurnal and the tidal range (MIWS-MLWS)at Liscannor is 4.1 m (Admiralty Tide Tables). Sea temperaturesare lowest in February and highest in August. J Landscape and Geology The lagoon lies on the flat coastal plain ofClare consisting mostly of glacial drift. Relief ofthe area is broken by small moraines and the entire stretch of coastline is bordered by cobblestorm beaches, presumably derived from the glacial deposits. Solid geology isdescribed as Namurian Carboniferous and soils are poorly drained and mostly acid rl brown earths and peat (RLA. 1979). A large area ofPhragmites borders the eastern shore, surrounding landis mostly acid J grassland used for cattle grazing.

Lake Topography The lagoon is approximately 600m from north to south, 3-400 m across and has an approximate area of 20 ha.Most of the lake is very shallow and

1

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the substrate is sand with very few stones, except alongthe edge of the barrier. Water depth is deeper in the channels which have been dredgedthrough the reedbeds and in these areas the substrate contains more organic silt.

Hydrology A small river (Annageragh River) enters the lake in theeast and a channel meanders across the lagoon to the outlet pipe (dated1929) in the barrier. There is no sluice or attempt to control seawater enteringthe lagoon, but water levels in the lake appear to be high enough to preventseawater entering on most tides.

There is no noticeable daily tidal fluctuation in water levelof the lake, but a seasonal pattern is likely, whereby water levels rise in the winterwith the increased rainfall, and gradually decline to sometimes very low levels in thesummer.

Salinity and water quality No historical information concerning salinityor water quality is available. It seems likely that the lagoon isbrackish throughout most of the year. Cattle graze the surrounding areas of the lake, butthere are no obvious signs or apparent history of eutrophication within the lagoon.

7 Lj

J

2 Lough Donnell

9.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, UniversityCollege Dublin.

9.2.1 Methods

Environmental variables A transverse profile of the barrier was drawn using heightsmeasured with a builders level and staff. Water depths were measured usinga plumbline from an inflatable dinghy.

The position of each sample areawas determined using a GPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturersof the GPS state that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but alsoto record changes in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured usinga salinity refractometer (No. 1270, Chemlab, U.K., 1 %o. precision). A photographic recordwas made of the site and local information sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected bya combination of sweepnetting (mesh size 0.5 mm), sieving of sediment (1 mm mesh) and close inspectionof stones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxeswere constructed in the Zoology Dept. at U.C.D. according to the model described by Holmes & O'Connor(1988).. Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations A and B inorder to gain additional information concerning larger fish species which wouldnot be recorded using the above methods. Standard procedure was that followed by Moriarty (1975)and Poole (1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, J joined by a leader net, mesh size 16mm. The trap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 film., respectively. Nets were generally placedat right angles to freshwater inflows or tidal inlets in order to trap fish swimming from eitherdirection. All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in thesurvey are affected by many environmental and biotic J variables including season, state of the tide, weather,nature of the habitat and life

3

1 Lough Donnell 0 cycles of the species involved. It is therefore difficult to make quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are 0 sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution 0 within the water column. Abundance categories of present, common andabundant are purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were 0 used to identify remaining specimens, but many of these werelarval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for 0 identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (egJaera, hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify whenpreserved 0 (turbellarians, leeches). All Diptera are identified to family level. All Odonata positively identified were Ischnura elegans and it is assumed that early instars ofthis group were of the same 0 species. 0 9.2.2Results

Lough Donnell was sampled on 24.vi.96 during the first partof the survey, and from 0 8-9.viii.96 during the more intensive survey. Five sampling stations were selected in the lake to reflectthe influences of substrate, freshwater and tidal inflows. Positions of the sampling stations areshown in Fig. 9.2.1

Environmental Variables 0 Fig. 9.2.2 shows a profile of the barrier. Station A (OS 0041 7092) was located at the northwestcorner of the lagoon near the 0 outlet pipe from the lagoon (Plates 9.2.3 & 6). Inthis area water depth varied from 0 cm to 1 m, substrate was mostly sand with occasionalstones, and salinity measured 2- 6%o. Station B (OS 0441 7092) was located on the easternshore where the River Annageera enters the lagoon through a dense bed of Phragmite.s.The channel of the river has been dredged and the sampling area was restrictedto the margins of this D channel where depth varied from 25 cm to 1 m.Substrate was largely soft organic silts, with no stones and salinity measured 3-4%0. Ei Station C (OS 0399 7068) was located in the southeasterncorner of the lagoon, close to an area of Scirpus. Substrate consisted mostly of firm sand, depth varied from 25- 50 cm, and salinity measured 3%0. 0 Station D (OS 0022 7065) was located in the openwater area in the southwest corner of the lagoon, depth varied from 25-50 cm, substrateconsisted of sand, and D salinity measured 5%0. Station E (OS 0056 7075) was located on the westernshoreline of the lagoon against the barrier (Plate 9.2.4). Small seepage zones were observed onthe lagoon side of the C

0 4 J

70

05 00

Fig_ 9.2.1 Location Map of Sampling Stations in Lough Donnell, Co. Clare 10 m-- level 0 - waterof lagoon grass 0 o a a o 0 0 0 0 o Figure 9.2.2. Profile of Barrier at Lough Donnell, Co. Clare. O M. c a o 0 0 o c3 0 0 0 Table 9.2.1Fauna Recorded at Lough Donnell, Co. Clare. June and September,1996. () = records for June.

Sampling Stations ( L.T. = light-trap)

A L.T.A B L.T.B C L.T.CiD L.T.DI E ------' Porifera I Cm daria Turbellaria ------Nemertea

Annelids ; ------_ __- i Crustacea

Ostracoda I Copepods; Cimpedia MysidaceaiNeomysis integer _ + c c cl00 a a IsopodaiLigia oceanica + + ------+ Jaera nordmanni ; + Amphipoda Gammarus duebeni + + + Orchestia gammarella + Tanaidacea Decapoda Carcinus maenas + + Crangon crangon + (+)

Palaemonetes varians 1 Arachnids +

Insecta j Thysanura Ephemeroptera

Odonatallschnura elegans j o j

sp. 2 1

Plecoptera j Trichoptera (cases) + + Hemiptera!Corixidae a 150 o 2 a 50 a 40 Sigara stagnalis + + + + _ S. dorsalis + Notonecta viridis _ o Coleoptera Dryops luridus + *Gyrinus caspius

Haliplus flavicollis j j +

I H. lineatocollis ---- '- I + H. ruficollis + + H. wehnekei + +

Helophorus_ _ brevipalpis + j j + Hygrotus inaequalis - j j Noterus clavicornis + DipteralChironomidac=--Culicidae + + o a + 10~ - _ ' - - ! - Ephydridae + _ - - Mollusca - --- Prosobranchia HYdrobii dae a a o

Potamo pyrqns anti podarum + + + ! +

+ = present; o = occasional; c = common; a= abundant; F = fyke net = Station not known U

0 Table 9.2.1 cont.. Fauna Recorded at Lough Donnell, Co. Clare.June and September, 1996. ( ) = records for June. 0 Sampling Stations { L.T. = light-trap)

A L.T.A' B L.T.B C L.T.C11 D L.T.D E Pulmonata -- - -- EJ Opisthobranchia Bivalvia i 0 Bryozoa

Echinodermata_ _ I Tunic= _ 0 Teleostei Anguilla anguilla F. 4 Dicentrarchus labrax F 1 Gasterosteus aculeatus + 5 + + 15 o 7 0 Mugilidae F, 1 F, 7 Platichthvs flesus F, 1 F, 6 + Pomatoschistus micros + 2 + + 1 + 2 j 0

0

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0

0

0

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0

0

0

0

0 + = present; o = occasional; c = common; a= abundant; F = fyke net n Lough Donnell

barrier where salinities of up to 25 %o.were recorded, but in the sample area itself salinity measured 5-6%0., substrate consisted of sandand cobbles, depth varied from 10-40 cm.. Fauna The species recorded at the different stations, usingall sampling methods, are listed in Table 9.2. 1. Among 32 taxa listed, 27are identified to species. No attempt will be made to identify other groups. The list (excluding marginalspecies) comprises one marine species, 2 poly-mesohaline, 10 euryhaline, and 4 oligo-mesohaline,and 8 limnic species were recorded (Table 9.2.2). Two species(Sigara stagnalis and Palaemonetes varians) are listed asa lagoonal specialists in Britain (Davidson et al. 1991).

Differences between stationsare mainly correlated with habitat as the salinitywas similar at all stations. Sigara dorsalis, Notonectaviridis, Ischnura elegans and four of the Coleoptera were only taken at Bat the edge of the reed beds, while Jaera nordmanni and Ligia oceanicawere confined to the seaward shore where they were found under cobbles. Crangoncrangon, and Palaemonetes varians were only found at A, near the main tidal stream. Potamopyrgus antipodarum,Neomysis integer and Sigara stagnalis werecommon throughout the lake. Chironomid larvae constituted the only fauna in the sediment.

Table 9.2.2 Ecological categories of the recordedtaxa in Lough Donnell L = lagoonal specialist according to Davidson et al. (1991).

Marine Dicentrarchus labrax

Poly-mesohaline Crangon crangon Mugilidae

Euryhaline Neomysis integer Jaera nordmanni Gammarus duebeni Palaemonetes varians L Carcinus maenas Sigara stagnalis L Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps Platichthvs flesus

Oligo-mesohaline Gvrinus caspius Notonecta viridis Ischnura elegans Potamopvrgus antipodarum

Linlnic S. dorsalis Haliplus flavicolis FL lineatocollis 11. ruficollis H. tivehnckei Helophorus brevipalpis Hvgrotus inaequalis .Voterus clavicornis

5 u Lough Donnell 0

9.2.3Discussion tJ The faunal assemblage reflects the predominance of freshwater over marineinfluence throughout the lake. Although seawater may enter on most tides,it is flushed out by 0 the river water and no fucoids or marine fauna wereestablished near the sea inlet. The fauna was moderately rich and typical of a lagoon withpersistently low salinity but with an open inlet allowing some colonisation from the sea. 0 According to Southwood and Leston (1959), Notonecta viridis was onlyreported for Wexford and north Kerry. It has since been recorded atLady's Island L. by Healy et al. (1982) and Galvin (1992) and at the North Slobby Galvin (1992). It was found at 0 Lady's Island L., Tacumshin L., Kilkeran L. and at theNorth Slob during this survey. The record for L. Donnell is thus the most northerlyfor Ireland. 0 Dryops luridus and Haliplusflavicollis were not recorded at any othersite during the survey. tJ 9.2.4Threats 0 According to local information there are problems of disturbance towaterfowl caused by shooting. Any problems caused by eutrophication are likely to be smalldue to the regular 0 flushing of the lagoon either by fresh- or seawater.

There are no other apparent threats. 0

9.2.5Evaluation

Lough Donnell is a natural sedimentary lagoon impounded by animpressive cobble barrier through which seawater percolates and it is therefore ofinternational importance based on geomorphology. There is an unsluiced artificial outlet pipe through which seawaterenters. The aquatic faunal assemblage is typical of a system withpersistently low salinity. It is moderately diverse but no species of special interest were found. The lagoon is of fairly high ornithological interest for wildfowland waders. A small colony of sand martins (Riparia riparia) breed in the lowcliffs to the north of the lake. The lake is a proposed NHA (Site Code No. 1018). In conclusion, Lough Donnell is of relatively low conservation valuebased on its invertebrate fauna. It is of higher value ornithologically and perhapsfor commercially valuable fish species. Its highest conservation value is based onthe geomorphological and scenic value of the lagoonal barrier and for thesereasons its designation as a proposed SAC is recommended.

6 Lough Donnell

9.2.6References and AdditionalSources of Information

Admiralty. 1995. Admiralty TideTables: European waters includingthe Mediterranean Sea. Taunton,UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoonsof Britain: an overview andconservation appraisal. Biological Conservation49, 295-3 13. Carter, R.W.G. 1992Sea level changes. In: B.E. Williams(ed.) Climate Change. Studies on the implications for Ireland.Dept. of the Environment,125-171. Couper, A. (ed.)1983 The Times Atlas of the Oceans.Times Books Ltd. 272pp. Davidson, N. C. et al.1991. Nature conservation andestuaries in Great Britain. Peterborough, Nature ConservancyCouncil. Delany, S.1995. I-WeBS Report 1994-1995.IWC Birdwatch Ireland. 109pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap forcollecting marine crustaceans. Journal of the marine biologicalAssociation of the United Kingdom 68: 235-238. Hutchinson, C. 1986. Watching birds in Ireland.Irish Wildbird Conservancy.144pp. i Hutchinson, C. 1979.Ireland's wetlands and their birds.Irish Wildbird Conservancy, 201pp. rl Martin, A., P. Shipman, H. Brady and N. Hyde 1974 National CoastlineStudy, Vol. Li 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The smallfyke net as a sampling instrumentin eel research. J EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel (Anguillaanguilla (L.)) in the Burrishoole System,Ireland, with special referenceto growth and movement. Ph.D. Thesis, University ofDublin. Rohan, P.K. 1986. The climateof Ireland. The StationeryOffice. 146 pp. Royal Irish Academy. 1979. n Atlas of Ireland.. Preparedunder the direction of the Irish National Committee for J Geography. Royal Irish Academy,Dublin. 104 PP. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish WildbirdConservancy, 152pp.

J i

7 m m m " " " KA V4 m m m I" " . a Plate 92.5View of seepage area and saltmarsh in Lough Donnell

Plate 9.2.6View looking south across Lough Donnell, Station A (foreground). J

Lough Donnell

9.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

9.3.1Site Description(Fig. 9.3. 1)

This is a shallow sandy lagoon set in a fairlylow-lying landscape. Land to the north, south and south east is used for pasture. The shinglebarrier lies to the west, through J which a pipe connects the lagoon with the sea.

The valley of the River Annageeragh, at the end ofwhich the lagoon lies, comes in from the east and discharges its waters into the lough.There is no other freshwater inflow stream.

J Swamp vegetation occurs all around the eastern and southern shores,being fairly extensive in the east where it grades to fen and rush pasture, which extends some way back up the river valley. The north shore and thewestern, stony barrier shore are open in contrast. Shore slope is generally gradual except for shortstretches of very low sandy cliff in the north east. J 9.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects: n The locality of these is shown in Fig. 9.3.2. J Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves J and the adjacent habitat described. The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

8 u

0

0

0

0

0

0

D

0

0

a

0

KEy DoI, l Irecle5 codes 0 c {nve efaf ed sand faa s Phrarites au4ralis

-5 wa p / Fen 5ckoenoplec{-us 0 SSp.1 G 0

Fig. 9.3.1Lg Aak Danne<

N

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0

U

Fig. 9.3.2 Lough Donnell, Co.Clare: Location of Transects and Shore-based Survey Sections u

Lough Donnell 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional specieswere found the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substratewas also recorded. The position of each aquatic sample was recordedas `x metres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and 0 the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadratsor releves. Sample area was D generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during thecourse of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentagecover (using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentagecover value according to the Domm scale as follows: C

Domin. 10 91-100% G 9 76-90 % 8 51-75 % 7 34-50 % 0 6 26-33 % 5 11-25 % 4 4-10 % 0 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals 0

a 9 Lough Donnell

Frequency Values J Frequency of each species within the total number of samplesis expressed as follows: Frequency V 81-100 % IV 61-80 % 111 41-60 % II 21-40 % I LJ 1 1-20 %

7 Note: The NVC volume covering saltmarsh communities was not availableat the time LJ of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and n aquatic substrate were taken into account. Transectswere located at the outlet to the u sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

J 2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal ,1 communities and adjacent habitats and landuse. The results are presented here as descriptive notes, divided into sections along the shore accordingto changes in floristics, substrate and/or adjacent habitat. These points of changeare marked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the J descriptive notes. A brief site description was written for each lagoon. U Constraints

Time. Restrictions on the time available in which tocarry out this survey had the following consequences:

10 Lough Donnell 0

a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores. E

Identifications 0 Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this reportare in accordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of C Britain and Ireland: Stoneworts' (1992).

Evaluation 0

This section comprises a brief summary of thesurvey findings for each site, a grading G of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `valuable 'site is one that is shown to beof particular interest and that is considered to be worthy of conservation/protection. 0

0

II J

Lough Donnell rl A `Potentially Valuable ' site is one which this surveyindicates may be of interest and J which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest. J The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

9.3.3Results 1. Shore-based survey

Section A-B (Transect D)

Aquatic: Enteromorpha - patchy

J Sand substrate with occasional cobbles

Marginal: Sparse cover of Glaux maritima, Spergularia marina and Triglochin maritima. 1-2m strip

Adjacent:Festuca rubra - Trifolium repens grassland

Section B-C

Aquatic: Unchanged

Marginal:Unchanged

Adjacent:Lolium perenne- Cynosaurus cristatus - Agrostis stolonifera pasture

Section C-D

Aquatic: Ruppia maritima- occasional small low growing patches - maximum 2m2 Enteromorpha - sparse

Marginal:Unchanged

Adjacent:Unchanged

12 u

Lough Donnell 0 Section D-E 0 Aquatic: Unchanged

Marginal:Schoenoplectus lacustris ssp tabernaemontani single species swamp. 4-8m 0 Backing to Schoenoplectus- Scirpus maritimus co-dominant stand. 2-8m. Grazed Backing to 50cm sandy cliff 0

Adjacent: Unchanged G

Section E-F 0

Aquatic: Unchanged D Marginal: Scirpus maritimus single species swamp. 6-12m. Sparse Ruppiato 2m in Grading to Scirpus- Schoenoplectus co-dominant stand. 2-7m 0 Backing to Agrostis stolonifera- Eleocharis uniglumis dominated community as Transect C.1 m Backing to 30-60cm sandy cliff 0 Adjacent:Unchanged 0 Section F-G 0 Aquatic: Ruppia maritima- very sparse - no longer in patches Enteromorpha- sparse C Marginal:Schoenoplectus lacustris ssp tabernaemontani single speciesswamp. 3- lOm Backing to 30-50cm sandy cliff 0

Adjacent:Unchanged 0

Section G-H C' Aquatic: No aquatic vegetation

Silt substrate 0

Marginal:Schoenoplectus single speciesswamp. 15m 0 Backing to Agrostis stolonifera- Eleocharis uniglumis community as Transect C. 8-15m 0 Adjacent: Unchanged

l3 J

Lough Donnell

Section H-I (Transect A)

Aquatic: Unchanged

Marginal: Phragmites australis dominated swamp with abundant Schoenoplectus. 8-10m Grading to dense Phragmites with sparse understorey of salt tolerant- species. 2m Grading to dense Phragmites fen with sparse understorey of freshwater species. c.100m

Adjacent: Juncus efflsus - Agrostis stolonifera dominated wet grassland

Section I-J J Aquatic: Ruppia maritima - frequent low growing patches - maximum 2m2

Silt and sand substrate with occasional cobbles

Marginal:Schoenoplectus single species swamp. c.8m Grading to Phragmites single species swamp. c. 10m Grading to Phragmites fen community as H-I

Adjacent:Unchanged

Section J-K

Aquatic: Unchanged

Marginal:As H-I

Adjacent:Unchanged

Section K-L (Transect B)

J Aquatic: Ruppia maritima- fairly extensive, low growing Enteromorpha - >50m out only

Marginal: Schoenoplectus single species swamp. c.20m. Occasional pools with sparse Ruppia maritima Grading to open Schoenoplectus cover with abundant Phragmites shoots and salt-tolerant understorey. 8-10m Grading to dense Phragmites with freshwater fen vegetation. c. 100m

J Adjacent:Unchanged

14 u

Lough Donnell 0

Section L-M 0 Aquatic: Unchanged

Marginal:Schoenoplectus single species swamp. c.20m a

Adjacent:Unchanged 0

Section M-N 0

Aquatic: Ruppia maritima- almost continuous cover Enteromorpha - sparse 0

Marginal:Schoenoplectus single species swamp. 10-60m, average c.50m 0 Grading to Phragmites swamp and fen communities as I-J. c.100m

Adjacent:Unchanged 0

0

Section N-O 0

Aquatic: Ruppia maritima- open cover - c.30% Enteromorpha- sparse D

Marginal:Scirpus maritimus single species swamp. 10m Backing to Schoenoplectus single speciesswamp. 20m 0 Grading to Phragmites swamp and fen communitiesas I-J.

Adjacent:Unchanged 0

0 Section O-P

Aquatic: Unchanged a

Marginal:Schoenoplectus single species swamp. 20-80m 0 Grading to Schoenoplectus with salt tolerant speciesas K-L. 5-10m

Adjacent: 1 m dry stone wall 0 Agrostis stolomfera- Potentilla anserina pasture

0

0 15 J

Lough Donndl J

Section P-Q (Transect Q

Aquatic: Ruppia maritima - extensive 50- l 00m out, less so0-50m out, low growing Enteromorpha - sparse

Marginal:Mosaic of Scirpus maritimus single species swamps and Scirpus - Schoenoplectus co-dominant swamps. 40-50m Grading to Scirpus maritimus with species-poor salt tolerant vegetation. 4m Backing 30cm-lm sandy cliff

Adjacent:Agrostis stolonifera - Potentilla anserina - Eleocharis uniglumis dominant J with salt tolerant species

J Section Q-R

Aquatic: Ruppia maritima - occasional patches -

Marginal:Mosaic of Schoenoplectus single species swamps and Scirpus - Schoenoplectus co-dominant swamps. 12m Grading as P-Q

Adjacent:Unchanged

Section R-S

Aquatic: No aquatic vegetation

Silt substrate

Marginal:Open cover of Glaux maritima, Spergularia marina, Triglochin maritima. 4-6m

Adjacent:Unchanged

Section S-T

J Aquatic: Unchanged

Marginal:As Q-R J Adjacent: Unchanged

16 0

Lough Donnell 0 Section T-U 0 Aquatic: Unchanged

Marginal:As P-Q 0

Adjacent:Unchanged 0

Section U-V 0 Aquatic: Unchanged

Marginal:Open cover of Glaux maritima, Spergularia marina and Triglochin 0 maritima. 2-8m Grading to Agrostis stolonifera- Potentilla anserina - Eleocharis uniglumis 0 community as Transect C D Adjacent:Lolium Perenne- Holcus lanatus - Cynosaurus cristatus pasture

Section V-W 0 Aquatic: Unchanged 0 Marginal:Scirpus maritimus dominated swamp with occasional Schoenoplectus shoots. 4-8m 0 Backing to open Glaux maritima communityas U-V. 1-2m strip

Adjacent:Festuca rubra- Trifolium repens sandy grassland. 40m 0 Backing to unvegetated shingle barrier a

Section W-X 0 Aquatic: Ruppia maritima- sparse Enteromorpha - sparse 0 Silt and sand substrate with occasional cobbles

Marginal:Open Glaux maritima communityas above with occasional Scirpus maritimus shoots.I m strip 0 Adjacent: Unchanged

D

0 17 J

Lough Donndl

Section X-Y (Transect D)

Aquatic: Ruppia maritma - faily dense and extensive, increasingly so tolandward J Enteromorpha - patchy ,

Marginal:Puccinellia maritima dominant with patchy Agrostis stolonifera, frequent J Glaux maritima and more or less sparse salt tolerant associates. 20m

Adjacent:Unvegetated shingle barrier

Section Y-Z

Aquatic: Unchanged

Marginal:Patches of Puccinellia dominated communityas X-Y - maximum area c.20m2 - with occasional single species patches of Puccinellia and Glaux maritima on sand substrate. 10m

Adjacent:Unchanged

Section Z-AA

Aquatic: Unchanged

Marginal:Unvegetated sand

Adjacent: Unchanged

UI

Section AA-BB

Aquatic: Unchanged

Marginal:Glaux maritima- Spergularia marina - Triglochin maritima community.I- 4m

Adjacent:Festuca rubra- Trifolium repens sandy grassland Backing to unvegetated shingle barrier

18 u

Lough Donnell 0

Section BB-CC 0 Aquatic: Ruppia maritima - absent to 50m out, then occurring inoccasional low growing patches - maximum 2m2 Enteromorpha - sbarse

Marginal:Unchanged 0 Adjacent: Unchanged

Section CC-DD

Aquatic: Enteromorpha - extensive cover 0 Marginal:Unchanged 0 Adjacent:Unchanged a

0

a

0

0

0

0

0

C

0 19 Lough Donnell

2. Transects

Site: Lough Donnell Transect code: A

Location: Freshwater inflow Sample point: 1 Aquatic - 5m out Sample area: 16m2 4x4 + grapnel Substrate:Silt

Depth: 60 cm Salinit : 0arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 0

Descri tion: No aquatic vegetationresent.

Site: Lough Donnell Transect code: A Location: Freshwater inflow Sampleoint: 2 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 0 - 30 cm Salinit : 0arts per thousand

NVC communit : S4 Phra mites australis swam- Phra mites australis sub-community Height (cm) Cover %) Total Plant 100

Phra mites australis 200 85 Schoeno lectus lacustris sstabernaemontani 100 20

Description. Dense Phra mites dominated swam with frequent Schoeno lectus.I Om.

20 Lough Donnell 0

Site: Lough Donnell Transect code: A 0 Location: Freshwater inflow Sam leoint: 3 Marginal Sample area: 20m2 10x2 Substrate: Peat

Depth: 0 cm Salinit : ----- 0 NVC communit :S4 Phra mites australis swam- sub-community undetermined Height cm Cover 0 Total Plant 100

Phra mites australis 230 100 0 Samolus valerandi 20 < I Tri lochin maritima 30 < 1 Aster tri olium 40 < 1 0 Mentha a uatica 30 < 1

0 Description: Phra mites dominant insp ecies-poor stand withsparse, mostly salt tolerant, associates. 2m. 0

0

Site: Lough Donnell Transect code: A 0 Location: Freshwater inflow Sample point: 4 Marg inal Sample area: 100m2 10x10 Substrate: Peat Depth: 0 cm Salinit ----- U. NVC communit :S4 Phra mites australis swam- Galium alustre sub-community Height cm Cover (% Total Plant 100 0

Phra mites australis 230 100 L hrum salicaria 80 15 A rostis stolonifera 20 < I Mentha a uatica 40 < 1 Potentilla anserma 15 < 1 Galium alustre 40 < I

Description: Dense sp ecies-poor Phra mites dominated fencommunity. c.100m. Grading to Juncus effusus- A rostis stolonifera dominated community.

21 J

Lough Donnell

Site: Lough Donnell Transect code: B

Location: Marginal swam Sample point: 1 Aquatic - 70m out Sample area: 25m2 (5x5) Substrate:Silt, sand, cobbles, boulders

Depth: 40 cm Salinit : 0arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 10

Enteromor ha 20 10

Substrate

Silt and sand 90 Cobbles and boulders 10

Description: Open cover of Enteromor ha. Restricted to submerged rocks.

Site: Lough Donell Transect code: B Location: Marginal swam Sample point: 2 Aquatic - 50m out Sample area: 25m2 5x5 Substrate:Silt, sand

Depth: 30 cm Salinit : 0arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 60

Ruis maritima 15 60

Description: Fairly open cover of low growing Ruia. Same species at more or less same cover from 20 - 60m out.

J

J

22 Lough Donnell 0

Site: Lough Donnell Transect code: B 0 Location: Marginal swam Sampleoint:3 Aquatic -I Om out Sample area: 25m2 5x5 Substrate: Silt, sand 0 Depth: 15 cm Salinit : 0arts per thousand

NVC communit : ----- Height cm Cover Total Plant 80

Ruis maritima 15 80 a

Description: Fairly dense cover of low growing Ruia. Both flowerin g and fruiting plants 0 resent. Same species at more or less same cover frommarginal swam to 20m out. D

0 Site: Lough Donnell Transect code: B Location: Marginal swam Sample oint: 4 Marginal Sample area: 50m2 10x5 Substrate: Silt 0

Depth: 5 cm Salinit : 4arts per thousand NVC community: S20 Schoenoplectus lacustrisssp tabernaemontani swamp -S.lacustris ssp tabernaemontani sub-community 0 Height (cm) Cover Total Plant 90 0

Schoeno lectus lacustris sstabernaemontani 130 90 0

Description: Tall dense single species Schoeno lectusswamp. 6m. C

0

0

0

0

E

0 23 Lough Donnell J

Site: Lough Donnell Transect code: B Location: Marginal swam Sample point: 5 Marginal Sample area: 96m2 12x8 - whole stand Substrate: Silt

Depth: 5 cm Salinit : 5arts per thousand NVC communit :S21 Scir us maritimus swam- Scir us maritimus sub-community Height cm Cover %) Total Plant 5

Scir us maritimus 50 5 Schoeno lectus lacustris sstabernaemontani 15 < 1 Ruis maritima 5 < 1

Description: Shallow pool with sparse Scir us dominant and verysparse low g rowing Schoeno lectus shoots. Ruis sparse and low growing, a few plants in bud.

J

Site: Lough Donnell Transect code: B Location: Marginal swam Sample point: 6 Marginal Sample area: 50m2 10x5 Substrate: Silt

Depth: 0 - 5 cm Salinit : 4arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp tabernaemontani sub-community Height cm Cover (% Total Plant 90

Schoeno lectus lacustris ss tabernaemontani 80 90

J Description: Dense single species Schoeno lectus swamp. 5m.

J

24 u

Lough Donnell 0

Site: Lough Donnell Transect code. B Location: Marginal swam Sample point: 7 Marginal 0 Sample area: 80m2 10x8 Substrate:Silt

De the 0 cm : Salinit ----- 0 NVC community: S20 Schoenoplectus lacustrisssp tabernaemontani swamp- Agrostis stolonifera sub-community Hei ht cm Cover (%) 0 Total Plant 95

Schoeno lectus lacustris sstabernaemontani 50 25 Phra mites australis 100 25 A rostis stolonifera 15 25 Eleocharis uni lumis 10 25 0 Glaux maritima 15 5 Tri lochin maritima 5 15 0 Atri lex hastata 15 < 1

Description: Open cover of co-dominant Schoeno lectus and Phra miteswith A rostis stolonifera and Eleocharis uni lumis co-dominantamong species-poor understore of salt tolerant species. 8m. 0

0

Site. Lough Donnell Transect code: B 0 Location: Marginal swam Sample point: 8 Marginal Sam le area: 100m2 10x10 Substrate: Peat Depth: 0 cm Salinit : ----- 0 NVC community: S4 Phragmites australisswamp - Atriplex hastata sub-community - Agrostis stolonifera variant Height (cm) Cover (%) 0 Total Plant 100

Phra mites australis 200 100 0 A rostis stolonifera 15 70 L hrum salicaria 40 < 5 0 Tri lochin maritima 20 < 1 Atri lex hastata 15 < 1 Galiumalustre 10 < 1 0

Bare substrate 20 0

Description: Dense Phra mites fen with A rostis stolonifera dominantamong st species-poor understore . c.100m. Grading to Juncus effusus- A rostis stolonifera dominated community. 0 25 Lough Donnell

Site: Lough Donnell Transect code: C

Location: Marginal swam Sample point: 1 Aquatic - 100m out Sample area: 25m2 5x5 Substrate:Silt, sand, cobbles

Depth: 30 cm Salinit : 0arts per thousand NVC communit :----- Height (cm) Cover (% Total Plant 75 Higher Plant 70

Ruis maritima 8 70

Algae

Enteromo ha 20 5

Substrate

Silt and sand 95 Cobbles 5

Description: Fairly dense low growing Ruis dominant with Enteromor ha restricted to -1 scattered submerged rocks. Same species at more or less same J cover 60 - 100m out. Site: Lough Donnell Transect code: C Location: Marginal swam Sample point: 2 Aquatic- 50m out Sample area: 25m2 5x5 Substrate:Silt, sand, cobbles

Depth: 15 cm Salinit : 0arts per thousand NVC communit :----- Height cm Cover (%) Total Plant 35 Higher Plant 30

Ruis maritima 8 30

Algae

Enteromor ha 20 5

Substrate

Silt and sand 95 Cobbles 5

Description: Open cover of low growing Ruis dominant with Enteromor ha restricted to submerged rocks. Same species at more or less same cover15 - 60m out.

26 0

Lough Donnell 0

0 Site: Lough Donnell Transect code: C Location: Marginal swam Sampleoint:3 Aquatic - IOm out a Sample area: 25m2 50 Substrate:Silt, sand, cobbles

Depth: 5 cm Salinit : 0arts per thousand NVC communit : ----- 0 Height (cm) Cover Total Plant 15 Higher Plant 15

Ruis maritima 6 15 a

Algae < I 0 Enteromor ha 15 < 1

Substrate 0

Silt and sand 100 Cobbles < 1 0

Description: Open cover of dominant low growing Ruis with very sparse Enteromor ha 0 restricted to submerged rocks. Same species at moreor less same cover 5 - 15m out.

Site. Lough Donnell Transect code: C Location: Marginal swam Sample point: 4 Aquatic- 3m out Sample area: 25m2 5x5 Substrate:Silt, sand, cobbles 0

Depth: 5 cm Salinit : 0arts per thousand NVC communit :----- Height (cm) Cover 0 Total Plant 60 E Ruis maritima 6 60

Substrate 0

Silt and sand 95 Cobbles 5 0

IDiscri tion: Fairlyopen cover of low rowin Ruis only. 0

0

0 27 Lough Donnell

Site: Lough Donnell Transect code: C Location: Marginal swam Sample oint: 5 Marginal Sample area: 100m2 10x10) Substrate:Silt, sand, cobbles

Depth: 5 cm Salinit : 4arts per thousand NVC communit :S21 Scir us maritimus swam - Scir us maritimus sub-community Height (cm) Cover %) Total Plant 100 FE her Plant 100

Scir us maritimus 70 50 Ruis maritima 5 70

Algae 10

Enteromor ha 10

Substrate

Silt and sand 95 Cobbles 5

Descri tion: Open Scius swam with fairly dense cover of low growing Ruia. Sparse free-floating Enteromor ha. Some Ruis plants in fruit.10m.

Site: Lough Donnell Transect code: C Location: Marginal swam Sample point: 6 Marginal Sam le area: 100m2 10x10 Substrate:Silt

Depth- 5 cm Salinit : 5arts per thousand

NVC communit : S21 Scir us maritimus swam - Scir us maritimus sub-community Height (cm) Cover Total Plant 85

Scir us maritimus 80 75 Schoeno lectus lacustris sstabernaemontani 80 10

Description: Fairly dense swam vegetation dominated bScir us with open Schoeno lectus cover. 15m.

n U

28 u

Lough Donnell 0

Site. Lough Donnell Transect code: C Location: Marginal swam Sample point: 7 Marginal 0 Sam le area: 100m2 (10x10) Substrate: Silt

De the 0 - 5 cm Salinit : 5 arts per thousand 0 NVC communit :S21 Scir us maritimus swam- Scir us maritimus sub-community Height cm Cover (% Total Plant 80 0

Scir us maritimus 70 80 0

Description:, Fairly dense single species Scir us maritimusswamp. 18m. 0

0

0 Site: Lough Donnell Transect code: C Location: Marginal swam Sample point: 8 Marginal 0 Sample area: 16m2 4x4 Substrate: Silt

Depth: 0 cm Salinit : ----- NVC communit :S21 Scir us maritimus swam- Scir us maritimus sub-community 0 Height cm Cover Total Plant 55 c Scir us maritimus 60 50 Tri lochin maritima 30 10 a S er ularia marina 8 < 5 Glaux maritima 6 < 1 0

Description: Open Scir us cover over veryopen round cover of salt tolerant associates. 4m. Backing sandcliff- average height 60 cm. 0

a

0

0 29 Lough Donncll

Site: Lough Donnell Transect code: C Location: Marginal swam Sample point: 9 Marginal Sample area: 16m2 (4x4 Substrate: Not known

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 100

A rostis stolonifera 10 90 Potentilla anserina 5 10 Eleocharis uni lumis 10 < 5 Glaux maritima 5 < 5 Tri lochin maritima 10 < 5 Leontodon autumnalis 10 < 1 S er ularia marina 5 < 1 H drocot le vul aris 4 < 1

Description: Dense cover of A rostis stolonifera dominant with frequentPotentilla anserina J among sparse associates. 32m. Grazed. Grading to Scir us maritimus dominated stands 25m. Backing unve etated flooded area 40m. Salinity 5. Grading to A rostis stolonifera- Potentilla anserina community (as above). 30m. Grading to Lolium erenne - Holcus lanatus- C nosaurus cristatus pasture.

7 J

J

J

30 1 Lough Donnell 0

0 Site: Lough Donnell Transect code: D

Location: Open shore- barrier Sample point: 1 Aquatic - 125m out Sample area: 25m2 5x5) Substrate:Silt, sand, cobbles 0

Depth: 25 cm Salinit : 5arts per thousand

NVC communit : ----- 0 Hei ht (cm) Cover (%) Total Plant 40 Hi her Plant 20 0

Ruis maritima 8 20 0 Algae 20 0 Enteromor ha 10 20

Substrate 0 85 Silt and sand 15 Cobbles 0

Description: Patch cover of co-dominant Ruis and Enteromor ha, t he latter restricted to 0

Site: Lough Donnell Transect code: D 0 Location: Open shore- barrier Sample point: 2 Aquatic- 100m out Sample area: 25m2 5x5 Substrate:Silt, sand, cobbles 0 Depth: 25 cm Salinit : 5arts per thousand

NVC communit : ----- Height cm Cover (%) 0 Total Plant 60 Higher Plant 30 E Ruis maritima 8 30 0 Algae 30

Enteromor ha 10 30 0 Substrate 0 Silt and sand 70 Cobbles 30 0 Description: Patch cover of co-dominant low growing Ruis and ru icolous Enteromorpha. 0 31 Lough Donnell J

J Site: Lough Donnell Transect code: D Location: Open shore - barrier Sample point: 3 Aquatic - 75m out Sample area: 25m2 5x5 Substrate:Silt, sand, cobbles

Depth: 15 cm Salinit : 5arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 90 FE her Plant 70

Ruis maritima 15 70

Algae 20

Enteromo ha 20 20

Substrate

Silt and sand 80 Cobbles 20

Description: Fairly dense cover of low growing Ruis dominant with Enteromor ha J restricted to submerged rocks. Same species at more or lesssame cover to shore. Shoreline - 50m out from the vegetation line at timeof survey. Backing 50m unve etated sand. jn

32 U

Lough Donnell 0

Site: Lough Donnell Transect code: D 0 Location: Open shore- barrier Sample point: 4 Marginal Sample area: 16m2 4x4 Substrate: Sand 0 Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height (cm) Cover %) 0 Total Plant 95

Puccinellia maritima 8 90 0 A rostis stolonifera 10 15 Glaux maritima 5 15 Tri lochin maritima 10 5 0 Aster tri olium 6 < 5 Atri lex hastata 10 < 1 0 S er ularia marina 5 < 1 Cochlearia an lica 4 < 1 Leontodon autumnalis 10 < 1 0 Suaeda maritima 8 < 1

E Description: Dense cover of dominant Puccinel lia in fairly lowgrowing salt tolerant community with Glaux and patchy A rostis stolonifera the onlyfrequently occurinassociates. 20m. a Backing shingle barrier of unve etated boulders and cobbles. 0

a Site: Lough Donnell Transect code: E Location: Outlet channel Sample point:1 Aquatic - 3m out 0 Sample area: 25m2 5x5 Substrate: Sand and cobbles

Depth: c. I m : Salinit 8arts per thousand . NVC communit :----- 0 Height cm) Cover (%) Total Plant 10 0

Enteromor ha 30 10 0

Description: Patch cover of Enteromor ha innarrow channel leading from outlet pipe. D

0

0 33 J

Lough Donnell n J Site: Lough Donnell Transect code: E Location: Outlet channel Sample point: 2 Marginal Sample area: 40m2 10x4 Substrate: Sand

Depth ------Salinit : -----

NVC communit : Undetermined Height (cm) Cover %) Total Plant 10

7 Glaux maritima 10 5 Lj S er ularia marina 6 < 5 Tri lochin maritima 15 < 5

Description: Sparse cover of s ecies- oor community onen sand shore. 4m Grading to Festuca rubra- Trifolium re pens grassland

9.3.4 Evaluation

`Not Valuable'

This is a shallow sandy lagoon with low salinity (0-5parts per thousand) at time of survey. Water depth exceeded 50cm at the outlet and thefreshwater inflow only. Therefore, the aquatic species of this lagoonwere more comprehensively surveyed than those of most sites. J Ruppia maritima is the only aquatic higher plant species.It is widely distributed across the site, being completely absent from the vicinities of theoutlet pipe and the freshwater inflow and the area of periodic floodingto the south only. Ruppia has a patchy cover to the north of the freshwater inflow anda more extensive cover to the south. It is typically low-growing.

There is a high diversity of swamp and other marginalcommunities. Scirpus maritimus, Schoenoplectus and Phragmitesoccur in mixed and single species stands on the eastern and southern shores. Theseare all fairly extensive in places. Eastern swamps grade to freshwater Phragmites fen. M

U A community of salt tolerant species with dominant Eleocharis uniglumisand Agrostis stolonifera occurs in the south. Anopen shore community consisting of Glaux maritima, Spergularia marina and Triglochin maritima is found inthe north and south of the site and Puccinellia maritima dominated saltmarsh vegetationborders part of the barrier shore.

Lough Donnell is an interesting site in terms of thediversity of its marginal communities. J However, aquatic species composition ispoor. Further survey is not recommended.

34 U

Lough Donnell a

Site: Lough Donnell Transect code: E a Location: Outlet channel Sampleoint: 2 Marginal Sample area: 40m2 10x4 Substrate: Sand

Depth: ----- Salinit : ----- 0 NVC communit :Undetermined Height (cm) Cover Total Plant 0 10

Glaux maritima 10 5 0 S er ularia marina 6 < 5 Tri lochin maritima 15 < 5 0

Description: Sparse cover ofspecies-p oor community ono en sand shore. 4m Grading to Festuca rubra- Trifolium re pens grassland 0

9.3.4 Evaluation 0

`Not Valuable' 0 This is a shallow sandy lagoon with low salinity(0-5 parts per thousand) at time of survey. Water depth exceeded 50cm at the outlet and thefreshwater inflow only. 0 Therefore, the aquatic species of this lagoonwere more comprehensively surveyed than those of most sites. 0 Ruppia maritima is the only aquatic higher plantspecies.It is widely distributed across the site, being completely absent from the vicinitiesof the outlet pipe and the freshwater inflow and thearea of periodic flooding to the south only. Ruppia hasa 0 patchy cover to the north of the freshwater inflowand a more extensive cover to the south.It is typically low-growing. 0 There is a high diversity ofswamp and other marginal communities. Scirpus maritimus, Schoenoplectus and Phragmitesoccur in mixed and single species stands on the eastern and southern shores. Theseare all fairly extensive in places. Eastern C swamps grade to freshwater Phragmites fen.

A community of salt tolerant species withdominant Eleocharis uniglumis and Agrostis G stolonifera occurs in the south. Anopen shore community consisting of Glaux maritima, Spergulana marina and Triglochinmaritima is found in the north and south of the site and Puccinellia maritima dominatedsaltmarsh vegetation borders part of the G barrier shore.

Lough Donnell is an interesting site interms of the diversity of its marginal communities. However, aquatic species composition ispoor. G Further survey is not recommended.

0 34 J

Lough Donnell

9.4 ECOTONAL COLEOPTERA J

J.A. Good PhD MIEEM FRES, Terrascope Environmental Consultancy, riverstick, Co. Cork

9.4.1 Site Description

Coastal brackish lake with cobble/boulder shingle barrier on sand (Plate1) breached by concrete inflow/outflow tunnel to beach, with seawater incursion at highspring tide, and inward percolation at base of barrier. Barrier shore with c.0.6 ha (summer) medium-textured aerobic and anaerobic sandflats, flooded at least during winter. Sandand loam margins to pasture, grading to large (> 2 ha) beds of Schoenoplectuslacustris, Phragmites communes and Scirpus lacustris, and upstream to extensive marsh area. Margins grazedby cattle. Inflow river with large watershed.

Subsites (Fig 9.4. 1)

1. Grass/Potentilla margin (R 001704) Lake margin pasture with grass and Potentilla anserina, Triglochirt maritimaand very sparse Schoenoplectus lacustris.

2. Pasture above cliff (R 002704) Short-turf pasture above c. 0.3 m loam cliff at lakemargin with Scirpus maritimus. Scirpus below cliff flooded durng spring high tide. J 3.Sandflat (R 001706, R 001709) Plate 9.4.2 Aerobic moist sandflats similar to intertidal sandflats in texture andporosity, behind barrier, between dry sandflat and standing water.

4. Pocket beach (R 004710) Plate 9.4.3 Small (c. 100 m2) sandy pocket beach to north ofriver outflow, with relatively high organic matter compared to sandflats above. Thousands of hydraenids active andburrowing in sand (Plate 4). Surrounded by c. 0.5 m sand cliffs topasture.

5. Sandy shore (R 000707, R 001711, R 004711) Gently sloping exposed sandy shore with cobbles, dried cow dung,rush and sedge litter in different parts of northern and interior shores.

9.4.2Methods Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that

35 J

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at LoughDonnell, Co. Clare Fig. 9.4. lMap of sampling sites(Carabidae and Staphylinidae)

I-Flotation, Ground search 2 - Ground search 3 - Cobble search 4 - Flotation 5 - Ground search 6 - Flotation 7 - Pitfall traps, S-vac 8 - Pitfall traps

1 u

Lough Donnell 0

this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, 0 washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes. 0 As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a 0 specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if: (1) they have a 0 restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems. 0

Interpretation of Indicator Species 0 Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat 0 (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see 0 Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, for instance). 0 Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for 0 instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992). 0

Limitations of Ratings 0 The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.)or herbivorous E assemblages (e.g. Lepidoptera). Different indicator speciesare likely to occur in spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areaswere sampled, including vegetation dominated by 0 Scirpus maritimus, JunCUS Marilimus, Juncos gerardi andgrasses, as well as bare or poorly- vegetated areas of sand, silt or peat. Particular emphasiswas given to habitat associated with 0 the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with

0 36 Lough Donnell

freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on J coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 9.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100x 1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. Habitat features associated with the sedimentary barrier, suchas shingle cobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs,were also sampled if they occurred to J a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring speciesmay be absent.

TABLE 9.4.1. Details of sampling methods.

Method Details No. replicates Sampling period, etc. per unit sample

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days J glycol preservative and plastic funnels; collars used where cattle/horses occur Cobble samples Cobbles turned 0.5- 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed, agitated soil floated in water

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain

37 U

Lough Donnell 0

Variety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare 0 sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is 0 not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site. G Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is 0 difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all 0 sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set. C

Weather conditions and sampling 0 The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather 0 forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. 0 This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks. 0 Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens ofmany of the other species have been retained in 0 the author's collection.

References 0 Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. 0 Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 0 14: 48-53.

0 Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from 0 (1) Grass/Potentilla margin- S-vac suction sampler (5 ix 1996), c. 2 m2; 0 38 0 Lough Donnell

(2) GrasslPotentilla margin - 6 plastic pitfall traps with funnels andethylene glycol preservative (5 - 21 ix 1996); (3) Pasture above cliff- 6 pitfall traps (5 - 21 IN1996); (4) Sandflat - 2 sets of flotation samples (fast and slowinfiltration sand, each sample = 24 subsamples of 5 x 5 x 10 cm, 20 vii1996),- (5) Pocket beach - 1 set of flotation samples (21 vii1996)l- (6) Debris on interior sandy shore (cow dung, plant litter, etc.)- lh ground search (21 vii 1996); (7) Sandy shore - lh ground search of cobbles (21 vii1996).

Species were selected as indicators of conservation value if: (1)they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems.

9.4.3Survey Results

Five species of carabid and twenty-four species of staphylinid wererecorded, two species of which are regarded as indicator species (Table 9.4.2).

TABLE 9.4.2Carabidae and Staphylinidae (Coleoptera) recorded from Lough Donnell. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), withthe exception of Booth (1988) for Tachyporus dispar.

Species No. individuals Carabidae

Agonum marginatum (L.)2 Agonum pelidnum (Payk.) I Bembidion bipunctatum (L.) 9 Indicator species Nebria brevicollis (F.) 3 Pterostichus sirenuus (Panz.) I

Staphylinidae

Aloconota gregaria (Er.) 1 Antischa analis (Grav.) I Atheta antplicollis (Muls. Rey) 4 Atheta celata (Er.) 3 Atheta elongatula (Grav.)28 Atheta graminieola (Grav.) 17 Atheta volans (Scriba) 22 Blediusgallicus (Grav.) I Carpelimus bilineatus (Steph.) I Carpelimus corticinus (Grav.) I Cypha punctum (Motsch.) I Indicator species Gabrius pennatus Sharp 3 Gabrius subnigritulus (Reitt.) 2 Grtvpeta carbonaria (Mannh.) 5

39 0

Lough Donnell 0 TABLE 9.4.2 (cont.) 0 Ischnopoda atra (Grav.) 1 Philonthus cognatus (Steph.) 8 Philonthus marginatus (Strom) 2

Platvstethus cornutus (Grav.) 1 a

Quedius schatzmayri Grid. 1 Stenus canaliculatus Gyll. 14 Stenus impressus Germ. I 0 Tachyporus chrysomelinus (L.) 1 Tachyporus dispar (Payk.) 2 Tachyporus pusillus Grav. 3 0

Bembidion bipunctatum is a halotolerant shore species, occurring inland andin coastal shingle a and brackish water pools (Koch 1989, Hyman and Parsons 1992).It is widespread but local in Great Britain (Hyman and Parsons 1992), and recorded from Ireland(Speight et al. 1982). It occurs from North Africa to west Siberia, and is commonat least in northern , a although rarer further west (Freude 1976).

Cypha punctum appears to be rare in Europe, with apredominantly atlantic distrbution 0 (Horton 1967). There is one published Irish record (moss indunes, Co. Down, Allen (1975)) and another unpublished from Cladium and Carex in a fenspring (J.A. Good, unpublished). 0 The species has also been recorded from stream banks, wetmeadows and coastal cliff flushes (Koch 1989). 0 Only three individuals or three species were recorded from thesandflats (Table 9.4.3), none of which were sandflat specialists. 0

TABLE 9.4.3 Staphylinid assemblage from aerobic sandflat, Lough Donnell (flotation samples and ground search combined). 0

Species No. Main biotope a

.4 theta elongatula 1 Eurytopic, incl. disturbed soil Platystethus cornutus I Eurytopic, incl. sandy shores 0 Stenus impressus l Eurytopic, incl. pasture 0 9.4.4 Evaluation

Of low conservation interest for terrestrial ecotonal community. 0 (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating 0 The presence of two indicator species indicates conservation interest: Bembidionbipunctatum has been associated with shingle and brackish water habitats, andCypha punctum with wet 0

0 40 J

Lough Donnell

coastal soils. However, the latter species, which was represented byonly one individual may J breed in the freshwater marsh upstream from this lagoon. The sandflats at this site have little value, probably dueto disturbance by irregularly fluctuating water levels and possibly the lack of interstitial algae whichprovide a food source for Bledius communities. Two sets of pitfall traps in the Schoenoplectus andScirpus stands were flooded in September. The site is possibly of average value forwetland invertebrates, but the effect of this water-level disturbance needs to be investigated before this canbe confirmed.

9.4.5References

Allen, A. A, (1975) Records of, and notes on, someof the rarer Hypocyphtus spp. (Col., Staphylinidae). Ent. mon. AIag. 111: 191-192. Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Freude, H. (1976) Fam. Carabidae. In: Freude, H., Harde, K.W.and Lohse, G.A. (eds). Die Kafer Mitteleuropas. 2. Goecke & Evers, Krefeld. Horion, A_ (1967) Faunistik der Mitteleuropaischen Kafer. XI. Staphylinidae: Habrocerinae bis Aleocharinae (Ohne Subtribus Athetae). Feyel, Uberlingen-Bodensee. Hyman, P.S. and Parsons, M.S. (1992) A review of thescarce and theatened Coleoptera of Great Britain. Part 1. UK Nature Conservation Series No. 3,Joint Committee for Nature Conservation, Peterborough. Koch, K. (1989) Die Kafer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die Kafer Mitteleuropas. 12.1. Supplementband mit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die Kafer Mitteleuropas. Katalog. Goecke & Evers,Krefeld. Speight, M.C.D., Anderson, R. and Luff, M.L. (1982) An annotatedlist of the Irish ground beetles (Col., Carabidae + Cicindelidae). Bull. Jr. biogeog. Soc. 6:25-53.

J

41 L-A 16A 06A I" IL-Ai a-A I" I" IL--J M

v, a Lough Donnell 6

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Plate 3 Sandy pocket beach at Lough Donnell, Co. Clare

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Plate 4 Hydraenid burrow casts at Lough Donnell , Co. Clare

J Lough Donnell

9.5 SUMMARY AND EVALUATION

Lough Donnell is a medium-sized ( 20 ha) natural sedimentarylagoon and it is therefore of international importance based on the Habitats Directive This shallow lagoon is impounded by an impressive cobble barrier,approximately 7 metres high and 40 metres wide. A small river, theAnnageeragh River, enters the lagoon in the east and a pipe has been constructedthrough the barrier to prevent excessive flooding of the surrounding agricultural land. The lagoon is an ASI and a proposed NHA (Site1018) largely due to its ornithological value. No large numbers of wildfowl are recorded but itis mentioned by Sheppard (1993) as being of major interest for waders. n J

Geomorphology Exceptional Aquatic Fauna Moderate Vegetation No Value Ecotonal Coleoptera Low

Geomorphology

Lough Donnell is a classic coastal lagoon and although thereis an artificial outlet pipe through which seawater enters, the cobble barrier which impounds thelagoon was one of the most impressive of those encountered along the entirecoastline. For this reason J it is rated as of exceptional conservation value based ongeomorphology

Aquatic Fauna

Among 32 taxa listed, 27 are identified to species, twoof which (Sigara stagnalis and J Palaemonetes varians) are listed as a lagoonal specialists. Differences between stations are mainly correlated with habitat as thesalinity was similar at all stations. Sigara dorsalis, Notonecta viridis, Ischnura elegansand four of the Coleoptera were only taken at the edge of thereed beds, while Jaera nordmanni and I_igia oceanica were confined to the seaward shore wherethey were found under cobbles. Crangon crangon, and Palaemonetes varians were only found nearthe main J tidal stream. Potamopyrgus antipodarum, Neomysis integer and Sigara stagnalis were common throughout the lake. Chironomid larvae constituted the onlyfauna in the sediment. J

42 u

Lough Donnell a

This is the most northerly locality for Notonecta viridis inIreland. Dryops luridus and Haliplus flavicollis were not recorded at any other site duringthe survey. 0

The faunal assemblage reflects the predominance of freshwater over marineinfluence throughout the lake. Although seawater may enter on most tides,it is flushed out by 0 the river water and no fucoids or marine fauna wereestablished near the sea inlet. The fauna was moderately rich and typical of a lagoon withpersistently low salinity but 0 with an open inlet allowing some colonisation from the sea.

Based on the aquatic fauna and the relatively low numberof lagoonal specialists, 0 Lough Donnell is rated as of only moderate conservation valueas a coastal lagoon.

Vegetation 0

Water depth exceeded 50cm at the outlet and the freshwaterinflow only. Therefore, the aquatic species of this lagoon were more comprehensively surveyedthan those of 0 most sites.

Ruppia maritima is the only aquatic higher plant species.It is widely distributed 0 across the site, being completely absent from the vicinities ofthe outlet pipe and the freshwater inflow and the area of periodic flooding to thesouth only. Ruppia has a patchy cover to the north of the freshwater inflow anda more extensive cover to the 0 south. It is typically low-growing. 0 There is a high diversity of swamp and other marginalcommunities. Scirpus maritimus, Schoenoplectus and Phragmites occur in mixed and single speciesstands on the eastern and southern shores. These are all fairlyextensive in places. Eastern 0 swamps grade to freshwater Phragmites fen.

A community of salt tolerant species with dominant Eleocharis unighmiisand Agrostis 0 stolonifera occurs in the south. An open shore community consistingof Glaux maritima, Spergularia marina and Triglochin maritima is found in thenorth and south of the site and Puccinellia maritima dominated saltmarsh vegetationborders 0 part of the barrier shore.

Lough Donnell is an interesting site in terms of thediversity of its marginal G communities. However, aquatic species composition is poor and the lagoonis rated as of no conservation value. G Further survey is not recommended.

Ecotonal Coleoptera 0

Five species of carabid and twenty-four species of staphylinid wererecorded, two species of 0 which are regarded as indicator species

Bembidion bipunctatum is a halotolerant shore species, occurring inland andin coastal shingle 0 and brackish water pools. It is widespread but local inGreat and recorded from Ireland

0

43 r1l Lough Donnell

(Speight et al. 1982). It occurs from North Africa towest Siberia, and is common at least in northern Germany, although rarer further west.

Cypha punctum appears to be rare in Europe, with apredominantly atlantic distrbution. There is one published Irish record (moss in dunes, Co. Down, Allen (1975)) and another unpublished from Cladium and Carex in a fen spring Q.A. Good, unpublished). The species has also been recorded from stream banks, wet meadows andcoastal cliff flushes. n The presence of two indicator species indicates conservation interest: Bembidionbipunctatum has been associated with shingle and brackish water habitats, andCypha punctum with wet J coastal soils. However, the latter species which was represented byonly one individual, may breed in the freshwater marsh upstream from this lagoon.

The sandflats at this site have little value, probably dueto disturbance by irregularly fluctuating water levels and possibly the lack of interstitial algae whichprovide a food source for Bledius communities. Two sets of pitfall traps in the Schoenoplectus andScirpus stands were flooded in September. The site is possibly of average value forwetland invertebrates, but the effect of this water-level disturbance needs to be investigated before this canbe confirmed.

Only three individuals of three species were recorded from thesandflats, none of which were sandflat specialists.

For the above reasons, Lough Donnell is rated as oflow conservation interest for terrestrial ecotonal community.

Summary

Despite the artificial inlet running through the barrier and thenumber of tourists visiting this part of the coast during the summer, LoughDonnell is still relatively natural and unspoilt by adverse developments.

The lagoon is of relatively low conservation value based onits invertebrate fauna, vegetation and ecotonal coleoptera. It is of higher value ornithologically andperhaps for commercially valuable fish species. It is however a classic lagoon withone of the most impressive barriers of the entire coastline.

Based on the geomorphology and scenic value of the lagoonalbarrier, Lough Donnell is rated as of high conservation value. J Designation as a proposed SAC is recommended.

J 44 J J u u n COASTAL LAGOONS IN THE REPUBLIC OF IRELAND u r-1 u (VOLUME 111)

10. LOUGH MURREE u

,-I Brenda Healy i Geoff Oliver v Pat Hatch -1 Jervis Good u

r-'1 u February 1997

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Prepared for the National Parks and Wildlife Service

(BioMar/Life) vI

10 LOUGH MURREE

J CONTENTS 10.1 Study Area

10.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

10.2.1 Methods 10.2.2 Results 10.2.3 Discussion 10.2.4 Threats 10.2.5 Evaluation 10.2.6 References

10.3 Vegetation Survey J (Pat Hatch)

10.3.1 Site Description J 10.3.2 Methods 10.3.3 Results Shore based survey J Transect tables 10.3.4 Evaluation

10.4 Ecotonal Coleoptera (Jervis Good)

10.4.1 Site description 10.4.2 Methods 10.4.3 Results 10.4.4 Evaluation 10.4.5 References

10.5 Summary and Evaluation

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U Lough Murree

10. LOUGH MURREE, Co. Clare.

OS Grid Reference: M255 119, 1:50,000 Sheet No. 51 Alternative names: Lough Murry, Loch Muiri

J 10.1 STUDY AREA General Features

Lough Murree is situated on south side of Galway Bay,12 km west of Kinvarra, County Clare (Fig. 10.1.1). The lake has formed in limestonebedrock on which a cobble barrier has been deposited along the coastal side. Aroad now runs along this barrier between the lake and the sea. There is nodirect communication with the sea, Seawater may enter the lake occasionally by overtopping of thebarrier but the main routes are percolation and possibly through subterranean fissures in thebedrock. The area was surveyed in 1840 and referred to as LoughMurry - salt lake. The fauna of the lake was sampled by Lansbury (1965) and an ecologicalsurvey was carried out by Pybus & Pybus (1980). The lake has become highly eutrophic, with recurrent algal bloomsbut remains of interest due to its unusual geomorphology. Galway University has aresearch station near the lake.

L. Murree is included within a large proposed NHA referredto as the Galway Bay n Complex (Site code 268) U Climate and oceanographic influences 7 U (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate with a smallannual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 6°C in January and15-15.5°C in July. The growing J season (the period of mean daily air temperatures above 6°C) is 9.5 months and as snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1200 mm, and the number of raindays (1 mm or more) is J 175-200. Winds are mainly from the west and southwest. Meanannual hourly wind speeds are between 5.0-5.5 m/s and a maximum wind speedof 50 m/s is estimated to occur once in 50 years. The daily duration of brightsunshine averages 3.5-4.0 hours. J Mean relative humidity is around 85% as on all Irishcoasts. Marine processes in the area are dominated by long periodAtlantic swell waves with 7 U median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 m (Carter 1992).Maximum n wave heights (averaging once in 50 years) are 30-35 m(Couper 1983). Tides are semi- u

I cro cn 0 n Rossana \70 IllounE,etl,l o, Bop Caherloughlln r liacni Abbey East r i Mugkiliish Wett Baiyconlea 0 SiievenagappreArlnagapple or 9 a7 Abbey West F6 fort-Lou(PubaSk Halile1y 31 Eart 17 17 62i

. J n!! Lough Murree J diurnal and the tidal range (MHWS-MLWS) at Galway is 4.5m (Admiralty Tide r1M Tables). Sea temperatures are lowest in February and highest inAugust. LJ Landscape and Topography The lagoon lies on Carboniferous limestone onthe north-west side of the Burren area. Soils are lithosols andshallow rendzinas. The area is karstic, with numerous underground channels and surface drainage islow. The low areas surrounding the lake are mostly improved grassland and cerealswhile the hill to the east of the lake is relatively natural bare limestoneand rough grazing. J Lake Topography The lagoon is approximately 600 m from southwest to northeast, 300 m across at its widest point and totalarea is approximately 15 ha. Most of the lake is shallow (<2m) and is dividedinto northern and southern basins by a shallow central area. The substrate at the northern edgeof the lake is bare limestone, but deposits of sand, mud, gravel and stones are foundin various mixtures along the other shorelines. In central areas the bottom is covered witha soft mud, deeper than 2 m in the centre of the southern basin (Pybus &Pybus, 1980).

Hydrology There is no direct communication with the sea, but seawaterenters the lake by overtopping of the barrier, percolation and possibly throughsubterranean fissures in the bedrock. Seepage is evident on the grassyslope north of the lake where the salinity in puddles and trickles was in the mid20s. A small tidal pool exists to the northeast of the lake, which "communicates with the sea viaan underground fissure system.....and empties and fills during each tidal cycle" (Pybus &Pybus, 1980). Surface drainage is low due to the karstic nature ofthe bedrock, but there are two small springs, one on the east side and one onthe west side of the lake which drain J into the lake after heavy rainfall.

7f There is no daily tidal fluctuation in water level ofthe lake, but a seasonal pattern is U likely, whereby water levels rise in the winter with theincreased rainfall, and gradually decline in the summer. Salinity and water quality Pybus & Pybus (1980) recorded a seasonal salinity range of 9 to 16%a. In general, salinity decreased through thewinter as a result of increased n precipitation but highest salinity actually occurred in February coinciding with maximum water level which followed a period of onshore galescoinciding with spring j tides. n The lake was described as eutrophic in 1960 by Lansbury(1965). The situation J appears to have become progressively worse with repeated algal blooms. n u

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Lough Murree

10.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin

10.2.1 Methods

Environmental variables

Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to J mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site.

At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o. precision). A photographic record was made of the site andlocal information sought concerning the background and recent history. J Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification.

Fyke nets were used at stations A and D inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets J used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and rl returned alive whenever possible. J Limitations of Sampling Methods and Species Determination rl All sampling methods used in the survey are affected bymany environmental and biotic L variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons

3 Lough Murree D

between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of IJ the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are 0 purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were 0 used to identify remaining specimens, but many of these werelarval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for identification and these were often not available due to lowpopulation density and the IJ limited number of individuals collected in the time available (e.g.Jaera, hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify whenpreserved (Nemertea). 0 All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same 0 species.

10.2.2 Results IJ

Lough Murree was sampled on 23.vi.96 during the first partof the survey, and from 5- 7.vii.96 during the more intensive survey. 0

Five sampling stations were selected in the lake to reflectthe influences of substrate, 0 freshwater and tidal inflows. Fig. 10.2.1 shows the position ofthese sampling stations in the lake. 0 Environmental Variables Station A (OS 2542 1205) was located on the westernshore where a stream from a tidal spring enters the lagoon. Salinity in the stream measured35%o but in the sample 0 area was between 10 and 24 %o. Water depth variedfrom 0 cm to 1 m, substrate was mostly sand with occasional stones and finer mud along theshoreline where cattle had disturbed the soil. 0 Station B (OS 2557 1221) was located in a largertidal pool to the northwest of the lake. Substrate was coarse sand, soft in places with occasionalrocks, water depth was 0 50 cm - 1 m and salinity measured 20-27%0. Station C (OS 2566 1220) was located in the northernend of the lagoon. Substrate 0 consisted of limestone bedrock with deep fissures and pockets ofsand/silt, water depth was 0-50 cm above the bedrock and salinity measured l3%o. Station D (OS 2562 1177) was located on the southeasternshore where substrate 0 consisted of cobbles, occasional larger stones with anoxic sandy mud,depth varied from 0 cm -1 m and salinity measured 15%0. 0 Station E (OS 0056 7075) was located on the southwesternshoreline where the lake is closest to the barrier. Substrate consisted of deep anoxicmud, depth varied from 0- 80 cm and salinity measured l3%0. 0

0 4 0 J

ri J

J 12 n u

J

25

Fig. 10.2.1Location Map of Sampling Stations in Lough Murree, Co. Clare u

a Table 10.2.1. Fauna Recorded at Lough Murree. June and August1996. ( ) = records for June. EJ

ASamplingStationsB I D L. ------1 i I_.q C( D E 0 Porifera --. ------__ . ------i ! -- Cnidaria Turbel !aria 0

Nemertea Nemertea_ ! + c Annelida Hediste diversicolor 1 - Clitellio arenarius + + 0 Ostracoda Copepoda EI Cirripedia Mysidaeea Neomysis integer 1 1 + IsopodalJaeraischiosetosa 12 j 5 EI Ligia oceanica + + ! Amphipoda!Echinogammarus marinas + Gammarus duebeni + + C + + + 0 Hyale sp. a a + _Melita palmata i + Orchestiagammarella + EI i Tanaidaceaj Deeapodaj Palaemonetes varians + 21 0 1 o 4 Arachnids 0 Insects _ Thysanura

Ephemeroptera 1 EJ Odonatajlsehnura elegans + + Plecoptera! Trichoptera!(cases) + c

Hemiptera Cori xidae j Coleoptera'iEnochrus bicolor + Agabusnebulosus + + 0

DipteraChironomidae cj- j a a Culicidae + Syrphidae - - -- +-_ IJ Molluscs j

. ! 1 Prosobranchia! Hydrobiidae + 3 ! r Hydrobia ventrosa + + + + 0 _ I Potainopyrgus antipodaruiJ + + + y Littorina savatilis + 1 ~a Opisthobranchia IJ Pulmonatai T- -- Bivalvia'Cerastoderma glauciun shells C Bryozoa Y Echinodermata - - Tunicata G Tcleostei Anguilla anguilla E 1 _ c + 10 - -Gasterosteu.s uculeatus-- +- 9_ o 2 c 1 Pomatoschistus I C

+ = present; o = occasional; c = common; a= abundant; F = fyke net U J

Lough Murree

Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 10.2. 1. Among 25 taxa listed, 20 are identifiedto species; identification of remaining groups (Nemertea and larvae) will not be attempted. Thelist (excluding marginal species) comprises one marine species, 6 poly-mesohaline, 7 euryhaline,3 oligo-mesohaline, and one limnic species (Table 10.2.2). Three species arelisted as a lagoonal specialists in Britain (Davidson et al. 1991). No obvious patterns of species distribution correlated with salinity, vegetationor substrate could be detected in the lake. The pool Bcontained an impoverished version of the lake fauna, lacking Gammarus duebeni, Palaemonetes varians, insectsand sticklebacks. Fish were poorly represented in collections, apart from sticklebacksand one goby, and crabs were absent.

Table 10.2.2Ecological categories of the recorded taxa in Lough Murree (excluding marginal species). L = lagoonal specialist according to Davidson etal. (1991).

Marine Nemertea

Poly-inesohaline Clitellio arenarius Jaera ischiosetosa Echinogammarus marinus Melita palmata Hydrobia ventrosa L J Littorina saxatalis Euryhaline Hediste diversicolor Neomysis integer Gammarus duebeni Palaemonetes varians L Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps

Oligo-mesohaline Ischnura elegans Enochrus bicolor L Potamopvrgus antipodarunt

Limnic Agabus nebulosus

10.2.3Discussion

The species assemblage typifies a medium salinity lagoon which hasno direct contact with the sea. The medium salinity regime, good macrophyte growthand availability of both hard and soft substrates might be expected to provideconditions favouring a wide range of species, but the faunal richness was, in fact,low due probably to the limited opportunities for colonisation. In the absence of a sea inletor frequent overwash, marine colonists presumably enter by way of rock fissures orsome form of aerial transport. It is possible also that the eutrophic conditions whichresulted in a severe algal bloom in July may have depleted the fauna. Bloomsare not new to this lake, however, and were reported in the 1960s (Lansbury 1965).

5 LJ

Lough Murree 0

Previous studies indicate that conditions in the lake undergo widefluctuations resulting in important variations in faunal composition. In September 1960, thesalinity had 0 obviously been low for some time because the marginal vegetationincluded Glyceria, Mentha, Nasturtium, Elodea and other freshwater marsh plants and fourspecies of 0 Corixidae were identified in the lake (Lansbury 1965). The salinityin 1974 was similar to that of 1996 but the fauna indicated a lesssaline regime with corixids (Sigara stagnalis), a beetle (Enochrus halophilus) (both lagoonal specialists) and avariety of 0 larvae coexisting with Neomysis, Palaemonetes, Jaera and Potamopyrgus, while empty shells of barnacles and Pomatocerus indicated that a moremarine environment had existed in the past (Pybus and Pybus 1981). 0

None of the species identified can be described as rarein Ireland. 0 10.2.4 Threats

IJ The lake is highly eutrophic and appears to suffer fromrepeated algal blooms. The main threat to the lake is the continuation of thisproblem. There appear to be no other immediate threats. 0

10.2.5 Evaluation 0

Lough Murree is a rock lagoon of a special morphologicaltype occurring in karstic limestone and is therefore of international importance based on geomorphology. 0 There is a typical cobble barrier on the shore butthere is no visible connection with the sea and the lagoon appears to receive seawater through undergroundfissures in the limestone. 0 The lagoon is fairly well documented. There are published accountsof algae and Hemiptera and several studies of fauna and hydrology have beencarried out. The 0 presence of a University Field Station encourages further research projects. The lake obviously suffers from eutrophication and the invertebrate faunarecorded in this survey was poor. 0 The lake is part of the proposed Galway Bay NHA(Site Code No. 268) 0 In conclusion, based on aquatic invertebrate fauna Lough Murree isof little conservation value. However, as a representative of an unusual morphologicaltype of coastal lagoon its conservation value is high. lJ Designation as a proposed SAC is recommended. 0

0

0

0

6 0 Lough Murree

J 10.2.6 References and Additional Sources of Information Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate (Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. J Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United J Kingdom 68: 23 5-23 8. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird n Conservancy, 201 pp. u Lansbury, I. 1965. Notes on Hemiptera, Coleoptera, Diptera and otherInvertebrates of the Burren, Co. Clare and Inishmore, Aran Islands. Proc. R.Ir. Acad. Vol. 64B, 89-115. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFAIT23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special referenceto growth and movement. Ph.D. Thesis, Dublin University. Pybus, C. & M.J. Pybus. 1980. An Ecological Study ofLough Murree, A Brackish Water Lake in County Clare. Proc. R. Ir. Acad. Vol.80B, 367-384. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 J PP. Sheppard, R. 1993. Ireland's Wetland Wealth. Report of the WinterWetlands Survey, 1984/85 to 1986/87. IWC, Dublin. 152 pp..

7 no

so r rIn r Plate 102.1View looking southwest along the northern shore of Lough Murree,Station A r

0

Plate 10.2.2 View of small tidal pool near Lough Murree,Station B

me as

a r

0 i

0 Plate 40,2,3 View of tidal pool i

do

r Plate J C.2.4 View of the southern area of LoughMurree, Station E

AN J

Lough Murree

10.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

10.3.1 Site Description(Fig. 10.3. 1)

Lough Muree lies between Knockvorneen to the east and thesea to the west. Pastoral farmland borders the site to the north, south, south eastand immediate west. A public road runs close to the southern shore.

Marginal areas are typically narrow, with fringing emergent and sparseshore vegetation backing to more or less steeply sloping ground tothe south, east and west. A narrow band of Scirpus swamp is more or lesscontinuous along the southern and eastern shores and occurs in patches along the western shore.Limestone pavement forms the north east shore.

There is no freshwater inflow stream. Two small saline streamsjoin the lough at the north end and half way along the western shore (noflow in either at time of survey). These are associated with small unvegetated saline pools which liebetween the lough and the sea.

10.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects J 2. Shore-based survey 1. Transects:

The locality of these is shown in Fig. 10.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

8 0

0

0

a

0

0

0

0

a

0

a

0

0

hEy: 0

11-- - < xPosedhec(rock((I lestone pavement) 0 -5wgrtiIq 10 i

DoriindrIf e5 0

1W1U5

9 t7jernYd 0

0

Fig. 10 3 1 0 T

N

TA - TO : Tramrct5 A-P : &J5 0/1 change in 4cVafi,/margt'nal ve9etaf

Fi`,10.3.2.Lough Muree, Co.Clare:Location of Transects and Shore-based Survey Sections J

Lough Murree 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and 0 the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one related to, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was 0 generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin 0 scale as follows:

Domin . 10 91-100% 0 9 76-90 % 8 51-75 % 7 34-50 % 0 6 26-33 % 5 11-25 % 4 4-10 % 0 3 <4 % -many individuals 2 <4 % -several individuals

1 <4 % -few individuals 0

0

9 J

Lough Murree

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % IV 61-80 % III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

J The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

10 0

Lough Murree 0

Constraints 0 Time. Restrictions on the time available in which to carryout this survey had the following consequences: 0 a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly 0 (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why this 0 is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was 0 working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores. 0 Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & 0 Wildlife Service

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is 0 recorded simply as `Enteromorpha'. 0 Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry Professor of Botany, University CollegeGalway 0 Nomenclature

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin 0 & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0

Evaluation 0 This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey. 0 The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal 0 communities are taken into account, though particular importance is puton aquatic maarophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as 0 `Valuable', `Potentially Valuable' and `Not Valuable'. 0

11 J n J Lough Murree

A 'Valuable' site is one that is shown to beof particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see 'Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

10.3.3 Results 1. Shore-based survey

Section A-B

Aquatic: Ruppia sp. - patchy cover to at least 20m out Potamogeton pectinatus - sparse Filamentous algae - extensive surface cover to 20m out Enteromorpha - sparse J Chara canescens - sparse Sand and gravel substrate with occasional cobbles

Marginal:Open Scirpus maritimus cover on gravel substrate with frequent cobbles and boulders. As Transect C. 4m Backing to 1 m strip Juncus gerardii, Glaux maritima, Potentillaanserma as Transect C

Adjacent:1.5m dry stone embankment Arable farmland

Section B-C

Aquatic: Unchanged

Marginal:Unvegetated stony shore. 2-4m n Backing to open cover of Juncus gerardii and Glaux maritimaon stony J shore. As Transect A.I m strip

Adjacent:Unchanged

12 Lough Murree

Section C-D 0 Aquatic: Ruppia sp. - sparse Potamogeton pectinatus - sparse 0 Filamentous algae - dense and extensive to c.20m out Enteromorpha - sparse 0 Marginal:Scirpus maritimus stands grading to Juncus gerardii- Glaux - Potentilla (as A-B) alternating along shore with J. gerardii - Glauxcommunity (as B-C). 0 Average extent of each community c.10-15m along shore

Adjacent:Unchanged 0

0 Section D-E (Transect A)

Aquatic: Ruppia sp. - sparse to c.25m out Potamogeton pectinatus - patchy to at least 50m out Filamentous algae- sparse Enteromorpha - patchy to c.50m out Lamprothamnium papulosum - sparse 0 Silt and sand substrate

Marginal:Open Juncus gerardii - Glaux maritima community with sparse Atriplex 0 hastata and Suaeda maritima. lm Grading to J. gerardii - Agrostis stolonifera dominated species-poor community. 35m. Grazed and poached 0 Grading to J. gerardii - Festuca rubra- Puccinellia maritima dominated community. 40m. Grazed and poached 0 Adjacent:Lolium perenne pasture 0 Section E-F

Aquatic: Potamogeton pectinatus - dense and extensive to at least 20mout 0 Filamentous algae- dense and extensive surface layer to c.20m out Enteromorpha- sparse 0 Sand and gravel substrate with occasional cobbles

Marginal:As C-D 0

Adjacent:Earth bank (height 4m) with Rubus fruticosus 0 Backing to Lolium perenne- Dactylis glomerata - Trifolium repens pasture 0

13 Lough Murree

Section F-G

Aquatic: Potamogeton pectinatus - as E-F Filamentous algae - as E-F Enteromorpha - as E-F Lamprothamnium papulosum - sparse Chara canescens - sparse

Marginal:Unchanged

Adjacent:Unchanged

Section G-H

Aquatic: Ruppia sp. - sparse Potamogeton pectinatus- sparse Filamentous algae- as E-F Enteromorpha - as E-F

Marginal:Juncus gerardii - Glaux maritima community as B-C

Adjacent:Unchanged

Section H-I (Transect B)

Aquatic: Ruppia sp. - sparse Potamogeton pectinatus- sparse Enteromorpha - dense and extensive to Sm out

Bedrock substrate

Marginal:Exposed bedrock substrate with occasional boulders Scirpus maritimus growing in fissures of limestone pavement. 10m

Adjacent:Limestone pavement with Festuca rubra, Pteridium aquilinum, Rubus fruticosus, Hedera helix, Prunus spinosa J Section I-J vI Aquatic: Potamogeton pectinatus- sparse Enteromorpha - sparse Filamentous algae- patchy surface cover to c.30rn out

Marginal:Unchanged

Adjacent:Unchanged

14 1 Lough Murree 0

Section J-K 0 Aquatic: Unchanged 0 Marginal:Unchanged

Adjacent:Agrostis stolonifera - Potentilla anserina grassland on limestone pavement 0 Section K-L 0 Aquatic: Potamogeton pectinatus - dense and extensive to at least 20mout Filamentous algae - dense and extensive surface layer to c.20mout Enteromorpha - restricted to shoreline rocks 0

Silt and sand substrate with occasional boulders 0 Marginal:As A-B. 1-5m strip

Adjacent:Earth and rock bank (height c.5m) 0 Backing to heath and grassland

Section L-M (Transect C) 0

Aquatic: Ruppia sp. - sparse to at least 20m out Potamogeton pectinatus - patchy to at least 20m out 0 Enteromorpha - dense and extensive to c.20m out Lamprothamnium papulosum - patchy to c.5m out a Chara canescens - sparse to c.5m out

Sand and gravel substrate with cobbles and boulders 0 Marginal:Unchanged 0 Adjacent: 1.5m dry stone wall Arable farmland D Section M-N

Aquatic: Ruppia sp. - sparse 0 Potamogeton pectinatus - cover unchanged Enteromorpha - cover unchanged 0 Silt and sand substrate with cobbles

Marginal:Unchanged 0

Adjacent:Agrostis stolonifera - Potentilla anserina grassland Backing to public road 0

a

15 Lough Murree

Section N-O (Transect D)

Aquatic: Ruppia sp. - dense patches from c.5m to at least20m out Potamogeton pectinatus - dense patches from c.5m to at least20m out Filamentous algae - dense and extensive surface layer to c.15m out Lamprothamnium papulosum - sparse Chara canescens - sparse

Marginal:Unchanged

Adjacent:Unchanged

Section O-P

Aquatic: Ruppia sp. - cover unchanged Potamogeton pectinatus- sparse Filamentous algae- dense and extensive to c.5m out Chara canescens - occasional dense patches to at least 12mout

Marginal:Unchanged

Adjacent:Unchanged

Section P-A

Aquatic: Ruppia sp. - dense and extensive to at least 30mout J Filamentous algae- sparse Enteromorpha - sparse

Silt substrate

Marginal:Dense Scirpus maritimus single species swamp. 5-12m Grading to Juncus gerardii- Agrostis stolonifera - Potentilla anserina community as Transect A. 5-15m. Grazed and poached

Adjacent:Unchanged

16 0

Lough Murree 0

2. Transects 0

Site: Lough Muree Transect code: A 0

Location: Saline stream inflow Sample point: 1 Aquatic - 55m out- grapnel Sample area: Grapnel only Substrate: Sand and silt 0 Depth: 50 cm + Salinit : 20arts per thousand

NVC communit : ----- Height (cm) Cover (% 0 Potamo etonectinatus Enteromor ha 0 Filamentous algae

0 Description: 0

0 Site: Lough Muree Transect code: A Location: Saline stream inflow Sample point: 2 Aquatic - SOm out 0 Sample area: 25m2 5x5 Substrate: Sand

Depth: 40 cm Salinit : 20arts per thousand

NVC communit : ----- 0 Height (cm) Cover (%) Total Plant 100 Higher Plant 40 0

Potamo etonectinatus 40 40 0

Algae 100 0 Enteromor ha 100 Lam rothamnium a ulosum 6 < 1 0

IDEC`6on: Open cover of Potamo etonectinatus beneath a free-floating algal mat. 0

0

0

0 17 Lough Murree

Site: Lough Muree Transect code: A Location: Saline stream inflow Sample point: 3 A quatic- 25m out Sam le area: 25m2 (5x5) Substrate: Sand

Depth: 30 cm Salinit : 20arts p er thousand

NVC communit : ---- Height cm Cover Total Plant 60 Higher Plant < 5

Ruias . 10 <5

Algae 60

Enteromor ha 60 Lam rothamnium a ulosum 10 5

Description: Sparse Lam rothamnium and low growing Ruis with a patchy cover of free- floatin Enteromor ha. Both flowering and fruiting Ruisresent.

Site: Lough Muree Transect code: A Location: Saline stream inflow Sample point: 4 Aquatic - IOm out Sample area: 25m2 5x5 Substrate: Sand

Depth: 30 cm Salinit : 22arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 20 Higher Plant 5

Ru is s p. g 5

Algae 15

Enteromor ha 15

Description: Sparse low growing Ruis beneath an open cover of free-floating Enteromor ha.

18 Lough Murree 0

Site: Lough Muree Transect code: A 0 Location: Saline stream inflow Sample point: 5 Aquatic- 5m out Sample area: 25 (5x5 Substrate: Sand 0 De the 20 cm Salinit : 24arts per thousand

NVC communit : ----- Height (cm) Cover 0 Total Plant 100

Enteromor ha 100 0

0 Description: Complete cover of Enteromor ha. No otherspeciesresent. Same cover to shore. 0

Site: Lough Muree Transect code: A 0 Location: Saline stream inflow Sample point: 6 Marginal Sample area: 5m2 5x1 Substrate: Sand, cobbles, boulders

Depth: 0 cm Salinit : ----- 0

NVC communit : Undetermined Height cm Cover %) 0 Total Plant 50

Juncuserardii 15 30 0 Glaux maritima 10 15 Atri lex hastata 5 5 Suaeda maritima 8 < 1 0

Bare substrate 50 0 Cobbles 20 Boulders 20 0 Sand 10

0 Description: Juncus Terardii dominant in open, species-poor community of salttolerant species forming 1 m wide strip along stony shore. 0

0

0

0

19 Lough Murree

Site: Lough Muree Transect code: A Location: Saline stream inflow Sample point: 7 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height (cm) Cover Total Plant 95

Juncuserardii 15 25 A rostis stolonifera 10 70 Potentilla anserina 8 5 Leontodon autumnalis 15 < 5 Glaux maritima 6 < 5 Planta o corono us 10 < 5 S er ularia marina 8 < 1 Planta o major 10 < 1 Lolium erenne 20 < 1

Description: Juncus erardii and A rostis stolonifera dominant inrazed ve getation on poached round, extending back to 35m from the low hin a low lying areac. 75m x 25m bordered b higher round to north east and southwest. Saline stream passing through this communit to the low h. No flow at time ofsurvey.

20 v

Lough Murree 0

Site: Lough Muree Transect code: A 0 Location: Saline stream inflow Sample point: 8 Marginal Sample area: 16m2 (4x4) Substrate: Peat

Depth: 0 cm Salinit : ----- 0

NVC communit : Undetermined Height cm Cover Total Plant 70 0

Juncuserardii 20 10 D Festuca rubra 15 15 Puccinellia maritima 10 15 S erlaria marina 8 15 0 A rostis stolonifera 15 5 Planta o corono us 5 5 Glaux maritima 6 5 0 Juncus bufonius 5 < 5 Leontodon autumnalis 15 < 1 Tri lochin maritima 10 < 1 0 E 0 Description: Juncuserardii, Festuca rubra, Puccinellia maritima and Ser ularia marina all frequent with each species locally dominant. Vegetation razed, substrate heavilypoached with u to 50% bare round inlaces. This community extends back 40m (x 20m and 0 borders an unve etated saline pool of 20cm depth attime of survey.

Grading to Lolium erenne pasture. 0

0

Site: Lough Muree Transect code: B 0 Location: Limestone pavement shore Sample point: 1 Aquatic - IOm out -grapnel Sample area: Grapnel only Substrate: Coarse sand Depth: 50 cm + Salinit : 20arts per thousand D NVC communit :----- Height (cm) Cover %) 0 Ru is s p. Potamo etonectinatus Enteromor ha 0

0 Description:

0

0

21 n Lough Murree

Site: Lough Muree Transect code: B Location: Limestone pavement shore Sample point: 2 Aq uatic- 5m out Sample area: 25m2 5x5 Substrate: Bedrock

Depth: 20 - 50 cm Salinit : 20arts per thousand

NVC communit : ----- Height (cm) Cover Total Plant 100 Hi her Plant 5

Potamo etonectinatus 70 5

Algae 95

Enteromo ha 15 95

Description. Enteromo ha dominant. P.ectinatus rowinsparsel y in fissures (grykes) of submerged limestone pavement.

Site: Lough Muree Transect code: B Location: Limestone pavement shore Sample point: 3 Marginal Sample area: 100m2 10x10 Substrate: Bedrock and silt

Depth: 0 cm Salinit : ----- NVC communit :S21 Scir us maritimus swam- Scir us maritimus sub-community Height (cm) Cover (%) Total Plant 5

Scir us maritimus 80 5

Description: Open limestone pavement with Scirus maritimus densel>rowin in silted fissures (grykes).10m.

22 0

Lough Murree 0

0 Site: Lough Muree Transect code: B Location: Limestone pavement shore Sample point: 4 Marginal Sam le area: 100m2 10x10 Substrate: Bedrock 0 Depth: 0 cm Salinit -----

NVC communit : Undetermined Height (cm) Cover (%) a Total Plant 40 0 A rostis stolonifera 30 35 Potentilla anserma 15 5 Juncuserardii 25 < 1 0 Leontodon autumnalis 20 < 1

0 Description: A rostis stolonifera dominant ins ecies- oor community growing in fissures (grykes) of limestone pavement. 12m. Grading to more densely vegetated limestonepavement with Festuca rubra, 0 Pteridium a uilinum, Prunus s inosa, Rubus fruticosus, Hedera helixfrequent. 0

0 Site: Lough Muree Transect code: C

Location: Marginal swam Sample oint: 1 Aquatic - 20m out Sample area: 16m2 4x4 Substrate: Coarse sand, cobbles 0

Depth: 70 cm Salinit : 20arts per thousand NVC communit :----- Height (cm) Cover (%) 0 Total Plant 100 Higher Plant 40 0 Potamo etonectinatus 60 40 Ruis s p. 60 < 1 0

Algae 70 0 Enteromor ha 70 a Description: Patches of dense Potamo eton ectinatus locally dominant withEnteromor ha forming a free-floating al al mat. Ru is in flower. Same species at more or less samecover 0 from IOm to at least 25m out.

0

0

23 Lough Murree

Site: Lough Muree Transect code: C Location: Marginal swam Sample point: 2 Aquatic- 5m out Sample area: 16m2 (4x4) Substrate: Sand,ravel, cobbles, boulders

Depth: 30 cm Salinit : 20 arts per thousand

NVC communit : ----- Height cm Cover Total Plant 95 Higher Plant < 1

Potamo etonectinatus 30 < 1

Algae 95

Enteromor ha 75 Lam rothamnium a ulosum 5 20 Chara canescens 6 < 1

Substrate

Sand andravel 50 Cobbles and boulders 50

Description: Patch cover of Enteromor ha withopen cover of low growing Lam rothamnium dominant below.

J

J

24 0 Lough Murree

0 Site: Lough Muree Transect code: C Location: Marginal swam Sample oint: 3 Marginal Sample area: 16m2 (8x2 Substrate: Sand,ravel, cobbles, boulders 0

Depth: 0 - 20 cm Salinit : 20arts per thousand

NVC communit : S21 Scir us maritimus swam- Scir us maritimus sub-community 0 Height (cm) Cover Total Plant 100 0 Scir us maritimus 50 40

Algae 80 0

Enteromor ha 80 0

Description: Open low growing Scius maritimus swam with dense cover of Enteromor ha 0 below. 3m wide strip along shore.

0

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25 J

Lough Murree

Site: Lough Muree Transect code: C Location: Marginal swam Sample point: 4 Marginal Sample area: 16m2 4x4 Substrate: Coarse sand, cobbles

Depth: 0 cm Salinit : -----

NVC communit : S21 Scir us maritimus swam- Scir us maritimus sub-community Height (cm) Cover %) Total Plant 40

Scir us maritimus 30 20 Glaux maritima 10 25

Substrate

Cobbles 80 Sand 20

Description: Open Scir us maritimus stand wit h Glaux theonly associated species. 4m wide strip on stopshore.

Site: Lough Muree Transect code: C Location: Marginal swam Sample point: 5 Marg inal Sample area: 16m2 8x2 Substrate: Coarse sand, cobbles

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height (cm) Cover (%) Total Plant 60

Glaux maritima 8 40 Juncuserardii 25 20 Potentilla anserina 8 5 A rostis stolonifera 15 < 1

Description: Glaux and Juncuserardii dominant in fairly open species- poor community forming 3m wide strip. Backing 1.5m dstone wall. Backing arable farmland.

26 a

Lough Murree 0

Site: Lough Muree Transect code: D 0 Location: Marginal swam Sample point: 1 Aquatic - 20m out Sample area: 16m2 4x4 Substrate:Silt, cobbles

Depth.- 80 cm + Salinit : 15arts per thousand 0 NVC communit :----- Height cm Cover (%) Total Plant 100 0 Higher Plant 100

Ruis s p. 85 60 0 Potamo etonectinatus 90 40 0 Algae 10

Filamentous algae 5 0 Lam rothamnium a ulosum 70 5 Chara canescens 60 < 1 0 Substrate 0 Silt 90 Cobbles 10 0 Description: Ruis and Potamo eton ectinatus co-dominant in dense bed with occasional patches of tall Lam rothamnium and very sparse Characanescens. Filamentous algae free-floating, sparse. Some Ruis plants in flower, some in fruit.Siltsubstrate of 0 10 - 20cm depth. 0

0

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27 0 Lough Murree

Site: Lough Muree Transect code: D Location: Marginal swam Sample point: 2 Aquatic- IOm out Sample area: 16m2 4x4 Substrate:Silt, Boulders

Depth: 30 cm Salinit : 15arts per thousand NVC communit :----- Hei ht (cm) Cover Total Plant 100 Higher Plant 30

Potamo eton ectinatus 40 25 Ruis s p. 35 5

Algae 90

Filamentous algae 90

Substrate

Boulders 70 Silt 30

Description: Open cover of Potamo etonectinatus dominant below free-floating al al mat. Both flowering and fruiting Ruis plantsresent.

Site: Lough Muree Transect code: D Location: Marginal swam Sample point: 3 Aquatic- 2m out Sample area: 16m2 4x4) Substrate:Silt, coarse sand, boulders

Depth: 0 - 15 cm Salinit : 15arts per thousand NVC communit :----- Height cm Cover Total Plant 100 Higher Plant < I

Potamo eton ectinatus 30 < 1

Algae 100 Filamentous algae 80 Enteromor ha 20

Substrate

Silt and sand 80 Boulders 20 Description: Filamentous algae forming complete surface layer with Enteromor haoccurring on frequent submerged rocks. Potamo etonectinatus very sparse.

28 0

Lough Murree 0

0

Site: Lough Muree Transect code: D Location: Marginal swam Sample oint: 4 Marginal 0 Sample area:l Om2 10x 1 Substrate: Peat, cobbles, boulders

Depth: 0 cm Salinit : ----- 0 NVC communit : S21 Scir us maritimus swam- Scir us maritimus sub-community Height (cm) Cover 70 Total Plant 0 Scir us maritimus 60 70 0 Bare substrate 50

Silt 30 0 Cobbles and boulders 20

E Description: Fairly open Scir us maritimus single species swam formingIm strip. 0

0 Site: Lough Muree Transect code: D Location: Marginal swam Sample point: 5 Marginal Sample area: 16m2 8x2 Substrate: Peat, cobbles, boulders 0

Depth: 0 cm Salinit : -----

NVC communit : S21 Scir us maritimus swam - A rostis stolonifera sub-community Height (cm) Cover 0 Total Plant 50 0 Scir us maritimus 40 30 Glaux maritima 15 20 A rostis stolonifera 10 < 1 0

Bare substrate 60 0 Peat 40 Cobbles and boulders 20 C

Description: Low growing open Scir us maritimus cover with Glauxdominant below. 3m. 0

0

0

29 0 Lough Murree

Site: Lough Muree Transect code: D Location: Marginal swam Sample point: 6 Marginal Sam le area:l Om2l Ox 1 Substrate: Peat, cobbles

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Hei ht (cm) Cover Total Plant 90

Juncuserardii 25 60 Glaux maritima 10 25 A rostis stolonifera 10 5 Potentilla anserina 8 < 5

Bare substrate

Peat 5 Cobbles 5

Description: Dominant Juncuserardii in dense patches with abundant Glaux.1 m strip- Grading to A rostis stolonifera- Potentilla anserina grassland on c. 45 degree slope to c. lm height backing to public road.

7 J 10.3.4 Evaluation

`Valuable'

The vegetation of Lough Muree is notable for its speciescomposition and for the abundance of these typically brackish water plants.

Salinity levels varied across the site from 13-24 partsper thousand at time of survey. There is no freshwater inflow stream. No marine higher plantor algal species were found here. Neither were there any aquatic angiosperms associated withmildly brackish conditions.

Ruppia and Potamogeton pectinatus occur within 20 metres of allbut the north eastern shores. P.pectinatus is dominant in dense beds along the easternand western shores with more or less sparse Ruppia. Ruppia is locally dominantover P.pectinatus in mixed beds along the southern shore.

It is notable that both Ruppia cirrhosa and R.maritima occurat this site.

30 0

Lough Murree 0

Two rare charophytes were already known to occur here- Lamprothamnium papulosum and Chara canescens. Both were re-found during the courseof this survey. 0 Both are occasional along the western shore. Lamprothamnium is abundantalong the southern half of the eastern shore and both species arefrequent to locally abundant amongst Ruppia and P.pectinatus to at least 20 metres outfrom the southern shore. 0 The presence of these rare charophytes is reason enough initself to regard this site as valuable. 0 Marginal vegetation is fairly uniform. Scirpus maritimus fringes all shores,typically forming a more or less narrow strip interrupted by occasionalopen stands of Juncus 0 gerardii dominated vegetation. Limestone pavement forms the north eastern shoreand here Scirpus grows in the fissures between the bedrock slabs. 0 Lough Muree seems to present a good example of abrackish water community subject to a middling range of salinity.Its macrophytes are abundant and its charophyte species particularly notable. 0 Full aquatic survey is recommended. 0

0

0

0

D

0

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0 31 0 J

Lough Murree

10.4 ECOTONAL COLEOPTERA J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

10.4.1 Site Description

Coastal brackish lagoon with shingle barrier and subterranean or subaquatickarst channel connections to, and possibly from, sea. Virtually no tidal response,but with seasonal water level fluctuation. Lake shore with organic-rich silty and sandy marginswith extensive algal growth, and with some limestone outcrops, boulders and cobbles (Plates1 and 2). Sparse Scirpus maritimus stands, but occasionally dense in patches.

Subsites (see Fig 10.4. 1)

1. Scirpus maritimus (M 252118) Plate 1 Small (c. 100 m2) stand of Scirpus maritimus on siltysand shore at nearest point to sea barrier. Extensive algal growth both on cobbles, shore sediment and onwater. Adjacent unvegetated shore with cobbles completely covered by bleached algal growth, withmany amphipods and some Ligia oceanica. Salinity of near-shore water was 22%o afterspring tide (29 ix 96).

2. Grass bank (M 254117) Bank several cm above unvegetated shore with Agrostis sp., Potentillaanserina, Juncus sp., etc. Likely to be flooded during winter. Salinity of near-shorewater was 11%o after spring tide (29 ix 96).

J 10.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that 7 this is shown by the presence of assemblages of specieswhich have specialised habitat LJ requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating thepresence of rare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

32 0

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loom 0

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Murree. Co.Clare and Staphytinidae)at Lough Fig. 10.4.1Map of samplingsites (Carabidae Ground search,S-vac 1 -Pitfall traps, 2 - Pitfall traps Lough Murree

Therefore, species were selected as indicators of conservation value if:(1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It would bedifficult to defend a categorization of sites into any finer categories than this (see Fosteret al. (1992), for instance). Sites were not rated of average value if there were less than twoindicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestriaUecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.)or herbivorous assemblages (e.g. Lepidoptera). Different indicator speciesare likely to occur in spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

J Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses,as well as bare or poorly- J vegetated areas of sand, silt or peat. Particular emphasiswas given to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques Lj The sampling methods used are listed in Table 10.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100x 1.5 sec. 'sucks' per subsample

33 Lough Murree 0 were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held 0 pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species 0 expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from the same type of plastic cups that were used for the traps themselves. 0 Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to 0 a sufficient extent (> severalm2) at the site. Sampling involved a fixed time groundsearch (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. 0 Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the species occurring during this period are 0 representative of the sites, even if spring species may beabsent.

0

TABLE 10.4.1. Details of sampling methods. 0

Method Details No. replicates Sampling period, etc. 0 per unit sample

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 0 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and plastic funnels; collars used 0 where cattle/horses occur Cobble samples Cobbles turned 0.5 - 2 m 30 0 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; 0 agitated soil floated in water

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during 0 warm weather without rain

0 Varieo; of sampling techniques Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique will be compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is 0

34 Lough Murree

not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site 7I (Aughimsh which has a spring/neap water level variation of >Im) where flooding U limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall trapswere placed varied from site to site. This is not regarded as biasing results toany great extent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens ofmany of the other species have been retained in the author's collection. rl j References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. hiogeog. Soc. 14: 48-53.

Methods used at this site 7 lJ Carabidae and Staphylimdae (Coleoptera)were recorded from :

(1) Scirpus maritimus area- S-vac suction sampler (4 viii 1996), c. 2 m2- J (2) Scirpus maritimus area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (4 viii- 29 ix 1996); (3) Unvegetated shore near Scirpus maritimus area- cobble search (30 cobbles, 7 vii 1996)1- (4) Grass bank - 6 plastic pitfall traps with funnels andethylene glycol preservative (29 ix - 18 x 1996).

n 35 u u

Lough Murree 0

Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they 0 are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. 0 10.4.3 Survey Results 0 Eight species of carabid and twenty-two species of staphylinid wererecorded, two species of which are regarded as indicator species (Table 10.4.2). 0

TABLE 10.4.2. Carabidae and Staphylinidae (Coleoptera) recorded from Lough Murree. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), andBooth 0 (1988) for Tachyporus dispar. 0

Species No. individuals 0 Carabidae

Bembidion assimile Gyll. 27 0

Bembidion lampros (Host) 1 Bembidion mannerheimi Sahib. 3 Bembidion minimum (F.) 42 0 Bembidion varium (01.) 1 Harpalus rufipes (Geer) 1

Leistus fulvibarbis Dej. 1 Loricera pilicornis (F.) 1

Staphylinidae 0 Aleochara lanuginosa Grav. 1

Anotylus rugosus (F.) 1 Atheta amplicollis (Muls. Rey) 5 0 Atheta fungi (Grav.) 1 A theta graminicola (Grav.) 2 Atheta vestita (Grav.) 22 Atheta volans (Seriba) 2 0 Brundinia meridionalis (Muls. Rey) 62 Indicator species Carpelimus corticinus (Grav.) 3 Cordalia obscura (Grav.) 26 0 Euaesthetus bipunctatus (Ljungh) 1

Gabrius pennatus Sharp 1 Geostiba circellaris (Grav.) 4 0 Ocvpus olens (Mull.) I Omalium laeviusculum Gyll. 9 Stenus brunnipes Steph. 2 Stenus canaliculatus Gyll. 2 0

Stenus fulvicornis Steph. 1 .Stenus nigritulus Gyll. 3 Indicator species Tachinus signatus Grav. 4 0 Tachyporus dispar (Payk.) 1 Xantholinus longiventris Heer 3 D 36 0 Lough Murree

Brundinia meridionalis occurred in abundance in the Scirpus maritimusarea (Table 2). It has not been previously recorded from Ireland. Although it is notlisted in Hyman and Parsons (1994) as rare or notable in Great Britain, it appearsto be rare or local in many parts of Europe (Porta 1926, Palm 1970, Benick & Lohse 1974, Mahler1987, Koch 1989). B. meridionalis is a halophilous species, recorded from tidal refuse andsilty soils on the coast and also on inland saline soils in Austria and other countries(Steel 1970, Koch 1989). Tidally undisturbed lagoons with stagnant water are favoured by this species- relatively large J populations were recorded on organic-rich soils with dense algal growthat three lagoons in this survey (also at Bridge Lough and Cloonconeen), but notat other sites.

Stenus nigritulus is only known in Ireland from one record(1910) from Lough Neagh (Anderson 1984), although it was also found at Tacumshin Lake(Co. Wexford) during this survey. It is very local and declining in Britain accordingto Hyman & Parsons (1994), and scattered and rare in France (Horion 1963). However, it isnot rare in Fennoscandia, and common in eastern Central Europe (Horion 1963). The species isrestricted to marshy shores, including flooded meadows (Horion 1963), riverbanks and salt-marshes (Hyman &Parsons 1994), but also on sea shores (Koch 1989).

All but one of the dominant and intermediate staphylinid speciesrecorded from the Scirpus maritimus stand were either halophilous or associated with riparian andmarsh habitats (Table 10.4.3). Several of these species were stenotopic. Species occurring indisturbed nutrient-rich agricultural soils were only present as singletons. In contrast, thesespecies were dominant in Bridge Lough, a similar lagoon on karst limestone.

TABLE 10.4.3. Staphylinid assemblage from Scirpus maritimusarea, Lough Murree (S- vac suction sample and pitfall traps combined). Abund. Cat. refersto category of relative abundance (no. individuals: 1, 2-10,11+).

Abund. Cat. Species No. Main biotope

Dominant Atheta vestita 17 Stenotopic halobiont, ripicolous Brundinia meridionalis 52 Halophilous, coastal

Intermediate Atheta graminicola 2 Marshes, shores of water bodies Atheta volans 2 Marshes, shores of water bodies Carpelimus corticinus 3 Ripicolous Cordalia obscura 2 Eurytopic Omalium laeviuscuhun 9 Halobiont, decaying seaweed Stenus canaliculatus 2 Sandy & silty shores, incl. coastal Stenus nigritulus 3 Stenotopic, marshy shores

Present J Aleochara lanuginosa I Eurytopic, incl. nutrient-rich cultivated land Anotvlus rugosus I Eurytopic, incl. nutrient-rich cultivated land Atheta amplicollis l Eurytopic, incl. nutrient-rich cultivated land

Atheta fmagi 1 Eurytopic, incl. nutrient-rich cultivated land

Euacsthetus bipunctatus 1 Marshes, pool margins Ocvpus olens I Grassland incl. dune grassland

Tachinus signatus 1 Eurytopic, incl. nutrient-rich cultivated land Tachvporus dispar l Grassland Xantholinus longiventris l Eurytopic, incl. nutrient-rich cultivated land

37 u

Lough Murree 0

10.4.4 Evaluation 0 Of average conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional] 0

Scientific Argument for Rating 0

The presence of two indicator species (Table 10.4.2), plus agroup of dominant/intermediate abundance ripicolous and halophilous species (Table 10.43), indicates an ecologicallywell- 0 developed system.

0

10.4.5 References 0 Anderson, R. (1984) Staphylinidae (Coleoptera) in Ireland - 3: Steninae.Ir. Nat. J. 21: 242- 251. 0 Benick, G. and Lohse, G.A. (1974) Staphylinidae II (Aleocharinae, Callicerini).In: Freude, H., Harde, K.W. and Lohse, G.A. (eds). Die Kdfer Mitteleuropas.5. Goecke & Evers, Krefeld. pp. 72-220. 0 Booth, R.G. (1988) The identity of Tachyporus chrysomelimus (Linnaeus) andthe separation of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Horion, A. (1963) Faunistik der Mitteleuropdischen Kdfer. IX. Staphylinidae: Micropeplinae 0 bis Euaesthetinae. Feyel, Oberlingen-Bodensee. Hyman, P.S. and Parsons, M.S. (1994) A review of thescarce and theatened Coleoptera of Great Britain. Part 2. UK Nature Conservation Series No. 12,Joint Committee for 0 Nature Conservation, Peterborough. Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die Kdfer Mitteleuropas. 12.1. Supplementband mit 0 Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die Kdfer Mitteleuropas. Katalog. Goecke & Evers,Krefeld. Mahler, V. (1987) Sjette tillaeg til "Fortegnelse over Danmarks biller"(Coleoptera). Ent. 0 Meddr. 54: 181-235. Palm, T. (1970) Skalbaggar, Coleoptera. Kortvingar: Staphylinidae. Underfam. Aleocharmae 0 (Atheta). Svensk Insektfauna no. 52: 117-296. Porta, A. (1926) Fauna Coleopterorum Italica. lI. Staphylinoidea. Piacenza. Steel, W.O. (1953) The entomology of Spurn Peninsula. IX. Coleoptera,Staphylinidae. 0 Naturalist 1952: 173-176; 1953: 125-129.

0

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0

38 0 Lough Murree 6

m

Plate 1 Western shore Lough Murree, Co. Clare

IN

a

r Plate 2 Southern shore Lough Murree, Co. Clare Lough Murree

10.5 SUMMARY AND EVALUATION

Lough Murree is a medium-sized (15 ha) rock lagoon ofa special morphological type occurring in karstic limestone. As a coastal lagoon it isof international importance based on the Habitats Directive. The lake is part of the proposed Galway Bay NHA(Site Code No. 268) The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology Exceptional Aquatic Fauna Low/Moderate Vegetation Exceptional Ecotonal Coleoptera Average

Geomorphology. Lough Murree is a coastal lagoon of a special morphologicaltype occurring in karstic limestone. There is a typical cobble barrier on the shorebut there is no visible connection with the sea. The lagoon appears to receive seawaterthrough underground fissures in the limestone, and possibly occasional over-topping of thebarrier during storms. Based on geomorphology, Lough Murree is rated as of exceptionalconservation value as a rare type of lagoon found in karstic limestone.

Aquatic Fauna

Among 25 taxa recorded, 20 are identified to species, includingthree which are listed as a lagoonal specialists in Britain. None of the speciesidentified can be described as rare in Ireland.

The species assemblage typifies a medium salinity lagoon which hasno direct contact with the sea. The medium salinity regime, good macrophyte growthand availability of both hard and soft substrates might be expected to provideconditions favouring a wide range of species, but the faunal richness was, in fact,low due probably to the limited opportunities for colonisation. In the absence of a sea inletor frequent overwash, marine colonists presumably enter by way of rock fissures orsome form of aerial transport. It is possible also that the eutrophic conditions whichresulted in a severe algal bloom in July may have depleted the fauna. Bloomsare not new to this lake, however, and were reported in the 1960s (Lansbury 1965).

39 u

Lough Murree 0

Previous studies indicate that conditions in the lake undergo widefluctuations resulting in important variations in faunal composition. The salinity in 1974was similar to that 0 of 1996 but the fauna indicated a less saline regimewith corixids (Sigara stagnalis), a beetle (Enochrus halophilus) (both lagoonal specialists) and a variety ofinsect larvae 0 coexisting with Neomysis, Palaemonetes, Jaera and Potamopyrgus, while empty shells of barnacles and Pomatocerus indicated that a more marine environmenthad existed in the past (Pybus and Pybus 1981). 0 Based on the relatively poor faunal assemblage and low numbersof lagoonal specialists recorded in the survey, Lough Murree is rated as ofonly low to moderate conservation value. 0

Vegetation 0

The vegetation of Lough Muree is notable for its speciescomposition and for the abundance of these typically brackish water plants. 0

Salinity levels varied across the site from 13-24 %o attime of survey. There is no freshwater inflow stream. Neither were there any aquatic angiosperms associatedwith 0 mildly brackish conditions.

Ruppia and Potamogeton pectinatus occur within 20 metres of allbut the north 0 eastern shores. P.pectinatus is dominant in dense beds along theeastern and western shores with more or less sparse Ruppia. Ruppia is locallydominant over P.pectinatus in mixed beds along the southern shore. 0

It is notable that both Ruppia cirrhosa and R.maritima occurat this site. 0 Two rare charophytes were already known to occur here -Lamprothamnium papulosum and Chara canescens. Both were re-found during the courseof this 0 survey. Both are occasional along the western shore. Lamprothamnium isabundant along the southern half of the eastern shore and bothspecies are frequent to locally abundant amongst Ruppia and P.pectinatus to at least 20 metresout from the southern 0 shore. The presence of these rare charophytes is reason enoughin itself to regard this site as valuable. 0 Marginal vegetation is fairly uniform. Scirpus maritimus fringes all shores,typically forming a more or less narrow strip interrupted by occasionalopen stands of Juncus gerardii dominated vegetation. Limestone pavement forms the north eastern shore 0 and here Scirpus grows in the fissures between the bedrockslabs.

Lough Muree seems to present a good example of abrackish water community subject 0 to a middling range of salinity.Its macrophytes are abundant and its charophyte species particularly notable. 0 Based on vegetation Lough Murree is rated as of highconservation value

Full aquatic survey is recommended. 0

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Lough Murree

Ecotonal Coleoptera

Eight species of carabid and twenty-two species of staphylinid wererecorded, two species of which are regarded as indicator species.

Brundinia meridionalis occurred in abundance in the Scirpus marilinuss area.It has not been previously recorded from Ireland. Although it is not listed inHyman and Parsons (1994) as rare or notable in Great Britain, it appears to berare or local in many parts of Europe. B. meridionalis is a halophilous species, recorded from tidal refuseand silty soils on the coast and also on inland saline soils in Austria and othercountries. Tidally undisturbed lagoons with stagnant water are favoured by this species - relatively largepopulations were recorded on organic-rich soils with dense algal growth at three lagoons inthis survey (also at Bridge Lough and Cloonconeen), but not at other sites.

Stenus nigritulus is only known in Ireland from one record(1910) from Lough Neagh (Anderson 1984), although it was also found at Tacumshin Lake(Co. Wexford) during this survey. It is very local and declining in Britain accordingto Hyman & Parsons (1994), and scattered and rare in France. However, it is not rarein Fennoscandia, and common in eastern Central Europe. The species is restricted to marshy shores, includingflooded meadows, riverbanks and salt-marshes, but also on sea shores.

All but one of the dominant and intermediate staphylinid speciesrecorded from the Scirpus maritimus stand were either halophilous or associated with riparianand marsh habitats. Several of these species were stenotopic. Species occurring indisturbed nutrient-rich agricultural soils were only present as singletons. In contrast,these species were dominant in Bridge Lough, a similar lagoon onkarst limestone.

The presence of two indicator species, plus a group ofdominant/intermediate abundance ripicolous and halophilous species, indicates an ecologically well-developed system.

Lough Murree is therefore rated as of average conservation valuefor terrestrial ecotonal community.

Summary J Lough Murree is a good example of a rare typeof rock lagoon receiving seawater by way of underground rock crevices.

J The lagoon is fairly well documented. There are published accountsof algae, Hemiptera, fauna and hydrology. The presence of a University FieldStation encourages further research projects. The lake obviously suffers from eutrophication and the invertebrate faunarecorded in this survey was poor. However, as a representative of anunusual morphological type of coastal lagoon with a rich aquatic flora its conservationvalue is high. Based on geomorphology, vegetation and an interesting ecotonal fauna, Lough Murree is rated as of high conservation value. Designation as a proposed SAC is recommended.

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J COASTAL LAGOONS IN THE REPUBLIC OFIRELAND J

(VOLUME 111)

It. AUGHINISH LAGOON

Brenda Healy Geoff Oliver n Pat Hatch J Jervis Good

February 1997

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Prepared for the National Parks and Wildlife Service

(BioMar/Life) J

rlff J II. AUGHINISH LAGOON

i CONTENTS

11.1 Study Area

11.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

11.2.1 Methods 11.2.2 Results 11.2.3 Discussion 11.2.4 Threats 11.2.5 Evaluation 11.2.6 References

11.3 Vegetation Survey (Pat Hatch)

11.3.1 Site Description 11.3.2 Methods 11.3.3 Result Shore based survey Transect tables i 11.3.4 Evaluation 11.4 Ecotonal Coleoptera (Jervis Good)

11.4.1 Site description 11.4.2 Methods 11.4.3 Results 11.4.4 Evaluation 11.4.5 References

11.5 Summary and Evaluation

i J Aughinish Lagoon

11. AUGHINISH LAGOON, Co. Clare.

OS Grid Reference: M 286 134, 1:50,000 Sheet No. 51 J Alternative names: ?

It. I STUDY AREA

General Features Aughinish Lagoon is situated on the south side of GalwayBay, 5 km west of Kinvarra, County Clare (Fig.1 1.1.1). The lake is impounded by a cobble barrierwith a n meandering outlet through the barrier at the eastern end. AMartello tower was J constructed on the barrier and the road leading to thetower originally had a bridge crossing this outlet. The bridge has now collapsed and theroad is partly eroded due to changes in the course of the outlet stream. Aughinish isa good example of a shallow, sometimes hypersaline, lagoon with a cobble barrier, fed to anunknown extent by underground channels. Very little is known about the lagoon: It appears tohave no protective status other than the fact that it is included within a largeproposed NHA referred to as the Galway Bay Complex (Site Code 268)

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) M The region experiences a mild oceanic climate with a smallannual temperature range U of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 5.5-6 °C in Januaryand 15-15.5 °C in July. The rl growing season (the period of mean daily air temperatures above6 °C) is 9.5 and as J snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1200 mm, and the number of raindays (1 mm or more) is 10 months. Prevailing winds are from the west and southwest. Meanannual hourly wind speeds are 5.0 m/s and a maximum wind speed of50 m/s is estimated to occur once in 50 years. The daily duration of bright sunshine averages 3.5-4hours. Mean relative J humidity is around 85% as on all Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressions which produce large waves, inshore breakers commonly exceeding 8 m (Carter 1992).Maximum wave heights (averaging once in 50 years) are 30-35(Couper 1983).Tides are semi- diurnal and the tidal range (MHWS-MLWS) at Galway is 4.5m (Admiralty Tide Tables). Sea temperatures are lowest in February and highest inAugust. Landscape and Geology The lagoon lies on Carboniferous limestone on the northwest side of the Burren area. Soils are described aslithosols or shallow organic soils and shallow brown earths. The area is karstic, withnumerous underground channels and surface drainage is low. The low areas surroundingthe lake are mostly J improved grassland and cereals.

1 Car,,Chadd3, 9'^ Flcna,,h llhoart,rrrnvd to II Bo,nBurren Bay rT'I BJ ly IIJIJt ar Morlyclogn Can on Mu,,u.a \, Pea .',. ifr ra R, aC, t. war Eachmse 25 rAny 56 N., _ 29 Ju , "I Blackhead Or Ba Bh,-w l B,a Iyvaghan Bay,Ui Bheachain ' . 3 IIn y atlY..o Sc n(2 rs ISljnd Flona, OSgalra ,. S . 26 I c jv0 ," 7 It 2.., .., cayle`.- AO!)", 0 M'ell r harp D / i O a mr,r,:au;'. ur 7t Cast MUC krn 5n WestCane lO gnlin / X13 Bealaclugget Iln .//Sna aliy vcn, Mn,,OLg n',nlanl,, I1]111C 61 'cc;, ^.-r riC cairn Nt,i.> I /fir //}} fl Boa! an Chwgrt jj l: NY" I -1 - Bale Ut 6heachalnBalyvaghan. rn f LliyfI':1 . ,. vdiagc Acres 0 0 o co 0 0 C3 c3 co 0 0 I 0 o c3 C7 CO C7 C7 C7 0 J Aughinish Lagoon rl J

Lake Topography The lagoon is approximately 600 m from west to east, approximately 200 m across and total area is approximately 10ha. Most of the lake is shallow (<2 m) and substrate includes limestone bedrock, with varyingamounts of large rocks, cobbles, sand and softer organic sediments at theless disturbed western end.

Hydrology There is no obvious freshwater inlet, but the lagoon lieson limestone bedrock and may be fed by underground channels. Spring tidesenter the lagoon through the outlet channel in the east and the barrieris overtopped at the lower J western end during storms. It is also possible that seawaterenters by percolation. There is likely to be a daily tidal fluctuation inwater level of the lake during spring tides only, but a seasonal pattern may occur whereby waterlevels rise in the winter with the increased rainfall, and gradually decline in thesummer. Water levels appear to have increased in recent times, flooding neighbouring fields (Plate 11.2.2). Salinity and water quality Salinity levels are likely to be close to that ofseawater with hypersaline conditions occurring during summertimeneap tides. There are no obvious eutrophication problems partly due to thefact that the lagoon is regularly flushed by seawater. The lagoon is small and shallow,however, and therefore vulnerable to water quality problems (see Bridge Lough, section 12).

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2 J Aughinish Lagoon

11.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin

11.2.1 Methods

Environmental variables A transverse profile of the barrier was drawn using heightsmeasured with a builders level and staff. Water depths were measured using a plumblinefrom an inflatable J dinghy.

J The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map and grid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o. precision). A photographic record was made of the site andlocal information sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0. 5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations A and E inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole (1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic 7 variables including season, state of the tide, weather, nature ofthe habitat and life J cycles of the species involved. It is therefore difficult to make quantitative comparisons Aughinish Lagoon 0 between lagoons, or even between stations withinthe same lagoon, as they are sampled at different times and often witha different sampling method. The results of the light-traps come closest to quantitative sampling,but even these are affected by 0 inter- and intra-specific relationships of the faunaand the non-random distribution within the water column. Abundance categoriesof present, common and abundantare purely subjective, and absolute numbersvary between taxa. 0 Several faunal groups were sorted and distributedto specialists. Standard keys were used to identify remaining specimens, butmany of these were larval or juvenile stages 0 and difficult to identify with certainty. Somegroups require adult males for identification and these were often not available dueto low population density and the limited number of individuals collected in the timeavailable. 0

11.2.2 Results EJ

Aughinish Lagoon was sampledon the 23.vi.96 during the first part of the survey,and from the 5-6.viii.96 during the more intensive survey. rJ Five sampling stations were selected in the laketo reflect the influences of substrate, and tidal inflows. Fig. 11. shows the position of these sampling stations inthe lagoon. 0

Environmental Variables 0 A transverse profiles at two places along the barrierwere drawn using heights measured with a builders level and staff. (Fig. 11.2.2). 0 Station A (OS 2845 1345)was located at the western end of the lagoon, whichis normally the most sheltered, except instorms when the barrier is overtopped (Plate 11.2.1). Water depth varied from 0cm to 1 m, substrate was mostly soft organic mud, 0 with numerous large stones, cobbles andgravel in places and salinity measured 40 %o Station B (OS 2867 1348)was located on the northern shoreline in the bay belowthe Martello Tower. Substratewas coarse sand, with occasional rocks, water depthwas 0 50 cm - 1 m and salinity measured 34 %o. Station C (OS 2867 1329) was located on the southern shore of the lagoon (Plate JJ 1 1.2.2). Substrate consisted of soft organic mudin the area where cattle were fed but was mostly large limestone rocks with varyingamounts of sand and cobbles in most of the sample area. Water depthwas 0-1.5 m and salinity measured 34 %o. 0 Station D (OS 28981346)was located at the eastern end near the outlet fromthe lagoon and the remains of the old bridge (Plate 11.2..4). Substrate consisted of cobbles D and occasional larger stones with patchesof coarse sand and gravel. Depth varied from 0 cm -1 m and salinity measured 34 %o.

Station E (OS 2863 1334)was located in the central, narrow part of the lagoon.A deep channel runs through this constrictedpart of the shoreline. Depth varies from 0- 3 m, substrate is sand with large rocks and cobbles and salinity measured 35 %o 0

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IJ Inner Galway Bay

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Fig. 11.2.1Location Map of Sampling Stations in Aughinish Lagoon, Co. Clare. 10 m. By Martello Tower 0 -of- water lagoon level E.H.W. of Lagoon grass beach 10 M. Lowest point, near Cobble barrier 0 M. 50 m 100 m level road 0 - ofwater lagoon Cobble barrier beach C C C7 C] C C7 E3 E3 E3 E3 Fig. 11.2.2 O M. Profile of Barrier at Aughinish Lagoon, Co. Clare. C7 E3 C7 C750 m C] E3 E3 C7 0 c 100 m C J Table 11.2.1. Fauna Recorded in Aughinish Lagoon, Co. Clare. Julyand August 1996. () = records for July.

Fauna Sampling Stations( L.T. = Tight-trap) ,L.T.Ai-r--B L.T.B! C jL.T.Cj D LTD E Porifera I Cnidaria Anemonia viridis + + _ -- -r te ---- - Chrysaora hvsoscella i + Dynamena pumila + - - -- Turbellaria Nemertea ; -- Annelida Arenicola marina + + Capitella capitata j + Hediste diversicolor + Lepidonotus squamatus + + Pomatoceros triqueter + I Polychaeta indef. Spirorbis rupestris + + Crustacea Ostracoda Copepoda + Cirripedia Balanus balanus + Semibalanus balanoides + + Mysidacea Mysidopsis gibbosa 10 22 22 Praunusflexuosus a 22 + + a 6 a 25 25

P. neglectus t Isopoda Idotea baltica +

Amphipoda Dexamine spinosa + + I Gammarus chevreuxi + G. duebeni +

G. locusta + + ! + + + Melita palinata ! _ Talitrus saltator + ' Tanaidacea _.- + + + Decapoda Carcinus maenas j + Crangon crangon c 6 a 2 + 2 2

Hippolyte varians 1 ! _ , - - o ! j Macropodium rostrata + I + + - Pagurus bernhardus + P. elegans a 1 a J P. serratus + o

Thoralus cranchii ! -_

Arachnida_ + Insecta ! -' ------_ Hemi tera Coleoptera ------Odonatal --- Plecoptera ------Trichoptera j _-

+ = present; o = occasional; c = common; a= abundant; F = fyke net u

Table 11.2.1. cont.. Fauna Recorded in Aughinish Lagoon, Co. Clare.July and August 1996. a () = records for July.

Fauna Sampling Stations ( L.T. = light-trap) 0 AL.T. B :L.T_BCL.T.CDL.T.tDE Ephemeroptera Diptera 0 Mollusca Polyplacophora Lepidochitona cinerea + + + 0 Prosobranchia Bittium reticulatum + + Gibbula umbilicalis c 1 Littorina littorea + 0 L saxatilis _ o Patella aspera + Opisthobranchia Aeolidia papillosa (+) EJ Elysia viridis + +

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Pulmonata j Bivalvia Cerastoderma edule ? + G Modiolarca tumida 1 Mytilus edulis + + + Ostrea edulis + + 0 Venerupis sp. 2 Bryozoa Alcyonidium gelatinosum +

Bowerbankia gracilis + LJ Cryptosula pallasiana + + EchinodermataAmphipholis squamata + + + Tunicata Ascidiella aspersa + + + + a A.scabra + + + + Botryllus schlosseri + + Clavelina lepadiformis + a Diplosoma lysterianum + + + Teleostei Anguilla anguilla F, 4 Ciliata mustela F, i 0 Pollachius pollachius F, 6

Pomatoscltistus micros + + I 0

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Ei + = present; o = occasional; c = common; a= abundant; F = fyke net 0 J

Aughinish Lagoon

Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 11.2.1. Among 56 taxa listed, 54 are identified tospecies. Four species (Balanus improvisus, Praunus flexuosus, Crangon crangon and Littorina saxatilis are J tolerant of lowered salinity and can be classed as polyhalinespecies; Hedisie diversicolor, Carcinus maenas, Anguilla anguilla and Pomatoschistus microps are euryhaline species. The remainder are marine species. One species (Gammarus chevreuxi) is listed as a lagoonal specialist in Britain (Davidsonet al. 1991), but the salinity range of this species is not known. As the salinity was equivalent to that of seawater, orhypersaline, throughout the lake, and there were no point sources of freshwater, only physicalhabitat differences are assumed to affect species composition and abundance at the differentstations. Both A and C were rocky with abundant algae and a numberof sessile and cryptic species were present, while at B and D there were softsediments and burrowing forms were well represented. No live burrowing bivalves were found, however, although shells of several species were plentiful.

11.2.3 Discussion

The faunal assemblage was almost entirely marine, all of thespecies classed as a polyhaline or euryhaline being common intertidally on rocky shores. Geomorphologically, the site shows the characteristics of a typical lagoonwith shallow water and a tidal inlet allowing only a small tidalrange. The paucity of species typical of brackishwater lagoons may be attributed to the small freshwaterinput, with most surface water on the surrounding land disappearing underground through infiltration. The only species of interest is Gammarus chevreuxi for whichthere are only two Irish records: a report by Spooner in the Plymouth Marine Fauna(1957) giving the position as "NE Ireland (rarely)", and a subsequent report by Pinkster(1978). The species is widespread in Europe in brackish habitats and is listed asa lagoonal specialist in Britain by Davidson et al. (1991) but Costello et al.(1989) list it as a species for which Irish records require confirmation. This was one of the fewlagoons in which J Gasterosteus aculeatus was absent

11.2.4 Threats J n There are no obvious eutrophication problems, partly due to the fact that the lagoon is regularly flushed by seawater. The lagoon is small and shallow,however, and therefore u vulnerable to water quality problems (see Bridge Lough, Section 12). It appears that water levels have been rising and manyof the small fields surrounding J the lagoon are now partly flooded. There may be athreat of infilling by local farmers in order to regain lost land.

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11.2.5 Evaluation 0

Aughinish is a natural sedimentary lagoon, having a cobble barrierand a natural inlet, and is therefore of international importance. based on geomorphology. 0 It is an unusual type as it is situated inkarstic limestone and probably receives seawater through subterranean rock fissures as well as by wayof the inlet, although 0 the fact that it becomes hypersaline suggests that seawater inthe lagoon is to some extent isolated. The aquatic fauna is unusual for a lagoon in thatit is almost entirely marine. The single 0 lagoonal species, a rare amphipod, was present in low numbersonly. The aquatic fauna of the lagoon is a rich collectionof marine species. The shallow 0 water and virtual absence of tides, together with the closeproximity to Galway, make it a potentially useful site for teaching purposes. The lagoon lies within the boundary of the proposed GalwayBay NHA (site Code 0 0268). In conclusion, although there was only one lagoonal specialist recorded,(both 0 faunistically and geomorphologically the conservation value of Aughinish Lagoon is high, and the site deserves protection and further study. Itsdesignation as a proposed SAC is recommended. 0

11.2.6 References and Additional Sources of Information 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department 0 Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. 0 Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-17 1. Costello, M.J., Holmes, J.M.C., McGrath, D. and Myers, A.A. 1989.A review and 0 catalogue of the Amphipoda (Crustacea) in Ireland. Irish Fisheries Investigations Series B (Marine), 33: 3-70. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. 0 Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 199-1-1995. IWC Birdwatch Ireland. 109pp. 0 Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine hological Association of the United 0 Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy 144pp. a Hutchinson, C. 1979.Ireland's wetlands and their hinds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde1974National Coastline Study, Vol. 0 1, Bord Failte/ An Foras Forbartha.

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Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/723 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand J movement. Ph.D. Thesis, Dublin University. Pinkster, S.1978. Amphipoda. In: Limnofauna Europea. lilies, J. (ed.) 2 ed. J Stuttgart, Fischer, 244-253. Plymouth Marine Fauna 1957. Marine Biological Association, UK. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp.Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under the directionof the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104pp Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp.

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Plate 1 1.2. 1 View of the western area of Aughinish Lagoon with theMartello Tower, Station A (foreground). r7

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Plate 11.2. 2View of flooded fields in Aughinish Lagoon, near Station C.

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J Plate 1 1.2. 3View of the barrier of Aughinish Lagoon From the MartelloTower.

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Plate 1L2- 4View of eastern area of Aughinish Lagoon,Station D. Aughinish Lagoon J

11. 3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

11.3.1 Site Description(Fig. 11.3.1)

This small lagoon is situated on a low-lying peninsula andbordered by pasture to the south and west and a shingle barrier with the seabeyond to the north and east. Dry stone walls criss-cross the adjacent farmland and run along thelagoon's southern and western shores in places.

There is no major freshwater inflow stream. The outlet channelruns out to the sea through the barrier from the eastern end.

Shore slope is generally gradual to the north and associatedwith saltmarsh, except along the steeper, sparsely vegetated shingle barrier. To the southand south west narrow shores quickly give way to rising ground and adjacentpasture.

An area of saltmarsh subject to periodic flooding lies justto the west of the lagoon.

6.3.2 Methods

J Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 11.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point. n J One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

8 Kcy:+ + + - SfoneSid wq( q le Shore PQMori «IneIIIu IIIO"a r,iarilirvici - Sa(icorflid d9y.- C,,,,ec(cj SQ (i i v D D D D ( D D D D Fig. 11.3.1 D ct inn,- CnD D D a D O D D D Lf= LI L r I L_] L-3 U F I L. L-I LA L-I L-I L] LA L_3 LI L> L_j L; N A-P:-rA-Trf 7NUr15ecf5 Of charge in aquafc/mdr7i'na( ve9ef,ffion High Wafer Mark Fig 11 32 Aughinish Lagoon, Co. Clare:: Shore-based Survey Sections Loca Lion of 'fransec Cs arld Aughinish Lagoon 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel 0 survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. 0

At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. 0 The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the 0 loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey.It was felt that this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for 0 other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips.All plant species in the sample area, their average height and percentage cover were recorded. 0

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the 0 transect.

Representative examples of every marginal community encountered during the course 0 of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentage cover(using the Domin 0 scale) and the calculation of frequency for each species:

Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows:

Domin. 10 91-100% 9 76-90 % 8 51-75 % 7 34-50 % 6 26-33 % 5 11-25 % 4 4-10 % 3 <4 % -many individuals 2 <4 % -several individuals

1 <4 % -few individuals

9 J

Aughinish Lagoon J

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % IV 61-80 % n III 41-60 % lI 21-40 %

J 1 1-20 % 7 Note: The NVC volume covering saltmarsh communities was not availableat the time J of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

J The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded. 7 LJ 2. Shore-based survey: n The surveyor walked around the entire shore recording aquatic species,marginal J communities and adjacent habitats and land use. The results arepresented here as n descriptive notes, divided into sections along the shore according tochanges in J floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

7 A brief site description was written for each lagoon. LJ Constraints

J Time. Restrictions on the time available in which to carryout this survey had the following consequences: J

10 u

Aughinish Lagoon G a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores. C

Identifications 0 Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0 Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of 0 Britain and Ireland: Stoneworts' (1992).

Evaluation 0

This section comprises a brief summary of the survey findingsfor each site, a grading E of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic mhcrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. E

A `Valuable ' .site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection. 0

0 11 0 Aughinish Lagoon

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

11.3.3 Results 1. Shore-based survey

Section A-B

Aquatic: Enteromorpha - sparse Filamentous algae - sparse Silt substrate with scattered cobbles

Marginal:Puccinellia maritima - Suaeda maritima- Salicornia agg. saltmarsh as Transect B

Adjacent:Outlet channel Shingle barrier

Section B-C (Transect A)

Aquatic: Filamentous algae - patchy J Codium tomentosum - patchy Fucus serratus - patchy Cystoseira foeniculata - patchy Ulva lactuca - sparse Polysiphonia elongata- sparse 7 Enteromorpha - sparse LJ Sand and gravel substrate with cobbles and boulders

Marginal:1-1.5m dry stone wall 2-3m strip of unvegetated silt and gravel shore Backing Puccinellia maritima- Suaeda maritima - Salicornia agg. saltmarsh. 3- 5m

Adjacent:Lolium perenne - Dactylis glomerata- Trifolium repens pasture

7 uI 12 L

Aughinish Lagoon 0

Section C-D 0 Aquatic: Cystoseira foeniculata Enteromorpha Filamentous algae - covers unchanged 0

Silt substrate with cobbles 0 Marginal:Unchanged

Adjacent:Unchanged 0

Section D-E 0 Aquatic: Cystoseira foeniculata Fucus serratus 0 Filamentous algae Enteromorpha Ulva lactuca - covers unchanged a Sand substrate with gravel and cobbles

Marginal:Cobble shore with sparse Puccinellia, Suaeda and Salicornia. 2-3m. Cover 0 <1%

Adjacent:2m dry stone wall a Backing Lolium pasture as before

Section E-F 0

Aquatic: Cystoseira foeniculata Filamentous algae 0 Enteromorpha Ulva lactuca - covers unchanged Silt substrate with gravel and cobbles

Marginal:Unchanged 0 Adjacent:Unchanged 0 Section F-G

Aquatic: Filamentous algae- sparse 0 Marginal:Puccinellia- Suaeda - Salicornia saltmarsh as Transect A. c. 10m. Poached C

Adjacent: Lolium pasture as before with occasional Primus spinosa and Crataegus monogyna 0

0 13

0 Aughinish Lagoon

Section G-H

Aquatic: Cystoseira foeniculata Enteromorpha Filamentous algae - all sparse

Silt, sand and gravel substrate

Marginal:Puccinellia - Suaeda - Salicornia saltmarsh strip as Transect A.0.5-1 in

Adjacent: 1.5m dry stone wall Lolium perenne - Holcus lanatus - Dactylis glomerata pasture

Section H-I

J As G-H but with stone wall running along shoreline Section I-J (Transect B) J Aquatic: Species unchanged

J Silt substrate

Marginal:Puccinellia - Suaeda - Salicornia saltmarsh. c.80m J Adjacent:Shingle barrier with open vegetation dominated by Festuca rubra and Armeria maritima

Section J-K

Aquatic: Cystoseira foeniculata- sparse Plocamium cartilagineum - sparse

Sand and gravel substrate with cobbles and boulders

Marginal: J Unchanged 7 Adjacent:Unchanged J Section K-L (Transect C)

Aquatic: Cystoseira foeniculata Plocamium cartilagineum Osmundia hybrida Filamentous algae - all sparse

Marginal: Unvegetated sand, gavel, cobbles and boulders of the shinglebarrier. 2-12m

Adjacent:Unchanged

14 n u Aughinish Lagoon 0

Section L-M 0 Aquatic: Unchanged

Marginal:Puccinellia - Suaeda - Salicornia saltmarsh strip as Transect A.1-4m 0

Adjacent:Unchanged 0 Section M-N

Aquatic: Cystoseira foeniculata 0 Enteromorpha . Filamentous algae - all sparse 0 Marginal:Extensive Puccinellia- Suaeda - Salicornia saltmarsh as Transect B. c.80m 0 Adjacent:Agrostis stolonifera - Festuca rubra- Armeria maritima grassland Backing shingle barrier 0 Section N-O 0 Aquatic: Cystoseira foeniculata Osmundia hybrida Enteromorpha a Filamentous algae - all sparse

Silt and gravel substrate with cobbles 0

Marginal:Unchanged. 4m 0 Adjacent:Unchanged

Section O-P 0

Aquatic: Cystoseira foeniculata 0 Osmundia hybrida Fucus serratus Enteromorpha 0 Filamentous algae - all sparse

Sand and gravel substrate with cobbles 0

Marginal:Unvegetated cobbles 0 Adjacent:Causeway Shingle barrier 0

0 15 J

Aughinish Lagoon J

2. Transects

Site: Au hinish Lagoon Transect code: A Location: Outlet to sea Sample point: I Aquatic - 2m out Sample area: 24m2 6x4) Substrate: Sand,ravel, cobbles, boulders

Depth: 40 cm Salinit : 33arts per thousand

NVC communit : ----- Height (cm) Cover Total Plant 70

Codium tomentosum 30 30 Fucus serratus 30 20 Filamentous algae 20 C stoseira foeniculata 20 15 Enteromor ha 20 < 1 J Ulva lactuca 15 < 1 Pol si honia elon ata 4 < 1 rl j Bare substrate 30

Sand and ravel 30 J

Description: Patches of unve etated sand andravel amongst algae-covered cobbles and boulders. Codium, Fucus and C stoseira patches covered in fiamentousalgae. Ulva and Enteromor ha restricted to landward edge of sample. Backing dstone wall - 1.2m high. P-7Backing 2.5m strip of unve etated silt andravel shore.

rl J r, 16 u Aughinish Lagoon 0

e

Site: Au hinish Lagoon Transect code: A Location: Outlet to sea Sample point: 2 Marg inal 0 Sample area: 16m2 (4x4) Substrate:Silt andravel Depth: 0 cm Salinity ----- 0 NVC communit : Undetermined Height cm Cover Total Plant 100 0

Puccinellia maritima 5 90 Suaeda maritima 15 15 0

Salicornia a . 15 < 5 Glaux maritime 5 < 1 0

Description: Puccinellia dominant inspecies-p oor saltmarsh community forming 4m wide 0 strip along the shore. Backing c.30 degree bank to 3m height with Festuca rubra- Briza media - Trifolium ratense grassland. 0 Backing Dact lislomerata meadow.

0

Site: Au hinish Lagoon Transect code: B 0

Location: Saltmarsh backing to barrier Sample oinc 1 Aquatic - 30m out Sample area: 25m2 (5x5) Substrate: Silt

Depth: 70 cm Salinit : 31arts per thousand

NVC communit : ----- Height cm Cover (%) 0 Total Plant 50

Filamentous algae 40 0 C stoseira foeniculata 25 20 0 Description: Open cover of C stoseira with free-floating filamentous algae. a

0

0

c 17 Aughinish Lagoon

Site: Au hinish Lagoon Transect code: B Location: Saltmarsh backing to barrier Sample point: 2 Aquatic - 20m out Sample area: 25m2 5x5 Substrate:Silt

Depth: 10 cm Salinit : 31arts per thousand

NVC communit : ----- Height (cm) Cover (%) Total Plant 10

Filamentous ale 10

Description: Sparse cover of free-floating filamentous algae only. More orless same cover 0 - 25m out.

Site: Au hinish Lagoon Transect code: B Location: Saltmarsh backing to barrier Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover (%) Total Plant 95

Puccinellia maritima 5 90 Suaeda maritima 10 30

Salicornia a . 15 25 S er ularia marina 8 < 5 Aster tri olium 15 rl < 1 J Armeria maritima 10 < l

Description: Puccinellia dominant, forming dense low growing round cover withSuaeda and Salicornia abundant. 80m. Backing shingle barrier. Festuca rubra dominant with Tri leuros ermum maritimum, Armeria maritima, Silene maritima frequent. Average vegetation cover c.60%.

18 J u

Aughinish Lagoon 0

0

Site: Au Thinish Lagoon Transect code: C

Location: Open shingle shore- barrier Sample point: 1 Aquatic - 5m out 0 Sample area: 25m2 5x5 Substrate: Sand,ravel, cobbles

Depth: 0 - 70 cm : Salinit 32arts per thousand 0 NVC communit :----- Height (cm) Cover (%) Total Plant 5 0

C stoseira foeniculata 20 5 Osmundia h brida 5 < 1 E Filamentous algae < 1

Substrate 0

Sand and ravel 90 0 Cobbles 10

0 Description: Sparse, species-poor al al community confined to scattered submergedcobbles. C stoseira dominant but restricted to larger rocks only. Backing shingle barrier. 0 Unve etated cobble and boulder shore 7m. Backing open Festuca rubra dominated vegetation on finer substrate with frequent Armeria maritima, Silene maritima, Tri leuros ermum maritimum, Rahanus 0 ra hamstrum. Average vegetation cover c.50%. 0

0

0

0

0

0

0

0 19 J

Aughinish Lagoon

11.3.4 Evaluation

`Not Valuable'

This is a high salinity site (31-33 parts per thousandat time of survey) with no major freshwater inflow.

No aquatic higher plant species occur here.

Cystoseira foeniculata is frequent around most of the site andis typically the dominant species, with the exception of the southern shore.

Fucus serratus, Ulva lactuca and Codium tomentosum are frequent andlocally abundant along the southern shore. Polysiphonia elongata is occasional here.

Plocamium cartilagineum is occasional up to 20m out from thenorthern barrier shore. Osmundia hybrida is rare here and near the northern shoreof the eastern section of the site.

The dominant marginal community is saltmarsh dominated by Puccinellia maritima, Suaeda maritima and Salicornia. This forms a narrow strip alongthe southern shores and a more extensive cover on the lower-lying ground tothe north of the site.

Further survey is not recommended.

I L.J

20 J

Aughinish Lagoon

11.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

11.4.1 Site Description

Coastal saline lagoon with shingle/sand barrier with tidal incursion duringspring high tides, and net water outflow during neap tides, resulting in monthlywater level fluctuations of >I in. Little apparent freshwater inflow, lagoon on karst limestone. Outflow channelwith cobble barrier exposed during neap part of cycle. Lagoon in twosections, with flooded field section to west (Plate 1), and with barrier inflow percolation to thisarea as well as overflow from eastern section. At neap part of cycle, much of shore exposed (Plate 2), grading through Armeria maritima and other halotolerant vegetation into dry coarse sand ofbarrier interior.

Subsites (Fig 11.4.1)

1. Salicornia salt meadow (M 286134) Salicornia/Armeria on damp sand, with offshore water salinity >35%o. Limestonestone walls dividing area into fields, with cobble stones on sand. Areaflooded at spring tides.

11.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently used criteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes. J As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was

21 u

0

0

N

0

II00 0

0

3 2 0 1

0

0

0

0

0

0

0

Fig.1 1.4. 1 Map of sampling sites (Carabidae and Staphylinidae) at eastern sectionof AuDhinish Lagoon, Co. Clare. 0

I - Pitfall traps 2 -Cobble search 3 - S-vac 0

0

0

0 J

Aughinish Lagoon

likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 11.4.1. Foreach site, a StihO BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. J

22 u

Aughinish Lagoon 0

0 TABLE 11.4.1 Details of sampling methods. 0

Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels, collars used where cattle/horses occur 0 Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin 0 Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; agitated soil floated in water

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent.

Variety of sampling techniques Several techniques will always give a more robust picture ofthe fauna of a site, because any 0 weather- or site-affected bias in one technique will be compensatedby other sampling methods. Some sites did not possess suitable habitat (peat cliffs,bare sand, cobbles on 0 sediment, etc.) for flotation, ground search or cobble search. Thisis regarded as an absence of habitat, rather than an unavailable sampling opportunity. That some sites,therefore, had more 0 sampling effort using these additional methods is not regarded assampling bias, but a genuine reflection of the habitat diversity of the site. 0

0

2 3 Aughinish Lagoon 3

Plate 1 Flooded fields in west section of Aughinish Lagoon, Co. Clare

Plate 2 Exposed shore at Aughinish Lagoon,Co. Clare J

Aughinish Lagoon

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Jr. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from (1) Salicornia salt meadow- S-vac suction sampler (4 viii 1996), c. 2m2; (2) Salicornia salt meadow - 6 plastic pitfall traps with funnelsand ethylene glycol preservative (4 viii - 8 ix 1996), (3) Salicornia salt meadow - cobble search (n = 30 cobbles)(4 viii 1996)

A further set of pitfall traps placed on the westside (flooded fields) of the lagoon were completely flooded and did not provide sample. J

24 u

Aughinish Lagoon 0 11.4.3 Survey Results 0 Only three species of carabid and one species of staphylinidwere recorded, none of which are sufficiently local to be regarded as indicator species (Table 11.4.2).However, with the exception ofBembidion minimum (which is halotolerant), all other speciesare stenotopic, 0 halobiont and ripicolous, and clearly adapted to the high levelsof flooding disturbance that occur at Aughinish. Dicheirotrichus gustavi, for instance was very abundant(Table 11.4.2), and did not occur at any of the other lagoonssurveyed. 0

0 TABLE 11.4.2.Carabidae and Staphylinidae (Coleoptera) recorded from Aughinish Lagoon. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0 Species No. individuals Carabidae a Bembidion minimum (F.) 10 Dicheirotrichusgustavi Crotch 47 Pogonus chalceus (Marsh.) 6 a Staphylinidae

Halobrecta flavipes Thoms. 2 0

0

11.4.4 Evaluation 0 Of no recorded conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional) a Scientific Argument for Rating 0 Indicator species were absent. The low number of specialist speciesis probably a result of a monthly cycle of a period of tidal flooding followed byperiod of dry conditions when the sandy substrate dries out. 0 11.4.5 References 0 Lohse, G.A. and Lucht, W.H. (1989) Die Kdfer Mitteleuropas. 12.1. Supplementband mil Katalogteil. Goecke & Evers, Krefeld. Lucht, W. H. (1987) Die Kdfer Mitteleuropas. Katalog. Goecke &Evers, Krefeld. 0

0

0

0 25 J Aughinish Lagoon

11.5 SUMMARY AND EVALUATION

Aughinish is a relatively small (10 ha) natural sedimentary lagoon,and is therefore of international importance based on the Habitats Directive. Very little is known about the lagoon except that itlies within the boundary of the proposed Galway Bay NHA (site Code 0268). The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology High Aquatic Fauna High Vegetation None Ecotonal Coleoptera None

Geomorphology. Aughinish is a relatively small (c10 ha) lagoon with atypical cobble barrier with an inlet but is of an unusual type as it issituated in karstic limestone and probably receives seawater through subterranean rock fissures as well as by wayof the inlet. The inlet was modified in the past by construction ofa bridge to carry a road. However, the bridge has collapsed and the inlet can againbe regarded as natural. Based on geomorphology, the lagoon is regarded as of highconservation value.

Aquatic Fauna Among 56 taxa recorded, 54 are identified to species. Fourspecies (Balanus improvisus, Praunus flexuosus, Crangon crangon and Littorina saxatilis are tolerant of lowered salinity but only species (Gammarus chevreuxi) is listedas a lagoonal specialist in Britain J As the salinity was equivalent to that of seawater, orhypersaline, throughout the lake, and there were no point sources of freshwater, only physicalhabitat differences are assumed to affect species composition and abundance at the differentstations. J The aquatic fauna is unusual for a lagoon in thatit is almost entirely marine. The single lagoonal species, a rare amphipod, was present in low numbersonly. In conclusion, although there was only one lagoonal specialist recorded,faunistically Aughinish Lagoon is rated as of high conservation value

26 Aughinish Lagoon 0

Vegetation 0

This is a high salinity site (31-33 %o at timeof survey) with no major freshwater inflow. No aquatic higher plant species occur here. 0

Cystoseira foeniculata is frequent around most of the site andis typically the dominant species, with the exception of the southern shore. Fucus serratus,Ulva lactuca and 0 Codium tomentosum are frequent and locally abundant along the southernshore. Polysiphonia elongata is occasional here. Plocamium cartilagineum is occasional up to 20m out from the northern barrier shore. Osmundia hybridais rare here and near 0 the northern shore of the eastern section of the site.

The dominant marginal community is saltmarsh dominated by Puccinellia maritima, 0 Sueda maritima and Salicornia. This forms a narrow strip alongthe southern shores and a more extensive cover on the lower-lying ground tothe north of the site. 0 The lagoon is rated as of no conservation value andfurther survey is not recommended

Ecotonal Coleoptera 0

Only three species of carabid and one species of staphylinidwere recorded, none of which are 0 sufficiently local to be regarded as indicator species. However, withthe exception of Bembidion minimum (which is halotolerant), all other species are stenotopic,halobiont and ripicolous, and clearly adapted to the high levels of floodingdisturbance that occur at 0 Aughinish. Dicheirotrichus gustavi, for instance was very abundant, and didnot occur at any of the other lagoons surveyed. 0 Indicator species were absent. The low number of specialist speciesis probably a result of a monthly cycle of a period of tidalflooding followed by period of dry conditions when the sandy substrate dries out. 0

Aughinish Lagoon is rated as of no recorded conservation valuefor terrestrial ecotonal community. 0

Summary

Aughinish lagoon is a good example of a true coastallagoon of an unusual type with rich collection of marine fauna. Salinity is always high butthe fact that it becomes 0 hypersaline indicates at least temporary isolation from the sea andrestricted tidal exchange. The aquatic fauna and vegetation are unusual for a lagoonin being almost entirely 0 marine The shallow water and virtual absence of tides, together withthe close proximity to 0 Galway, make it a potentially useful site for teaching purposes. Based on geomorphology and aquatic fauna, Aughinish Lagoon is ratedas of 0 high conservation value. Proposal as an SAC is recommended. 0

27 J

COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

J 12. BRIDGE LOUGH

Brenda Healy Geoff Oliver ,l Pat Hatch Jervis Good u

February 1997

Prepared for the National Parks and Wildlife Service

(BioMar/Life)

Li 12. BRIDGE LOUGH

CONTENTS

11.1 Study Area

11.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

12.2.1 Methods 12.2.2 Results 12.2.3 Discussion 12.2.4 Threats 122.5 Evaluation 12.2.6 References

12.3 Vegetation Survey (Pat Hatch)

12.3.1 Site Description 12.3.2 Methods 12.3.3 Result Shore based survey Transect tables 12.3.4 Evaluation

12.4 Ecotonal Coleoptera (Jervis Good)

12.4.1Site description 12.4.2 Methods 12.4.3 Results 12.4.4 Evaluation 12.4.5 References

12.5 Summary and Evaluation J

Bridge Lough J 12.1 BRIDGE LOUGH

OS Grid Reference: M 342 128, 1:50,000 Sheet No. 52(unpublished to date) Alternative names: ?

12.1 STUDY AREA

General Features Bridge Lough is situated on the south side of GalwayBay, 10 km west of Kinvarra, County Clare (Fig. 12.1.1). The lake is impounded by acauseway which allows a limited tidal exchange through a small outlet running througha channel under the road at the southern end of the causeway. Bedrock is limestoneand no visible streams enter the lagoon, but it may be fed by both fresh-and seawater through underground channels. The lagoon is small and shallow and appears to behighly eutrophic. Sediments consist of bare limestone rocks and a thick layer of organicmud. Open water areas are largely choked with growths of filamentous algae. Very little is knownabout the lagoon. Originally it was probably similar to Aughinish lagoon (see Section11), but restriction of tidal flushing through construction of the causeway with sucha small outlet appears J to have resulted in colmatisation and a concentration of nutrients. The lagoon is privately owned and it was not possibleto carry out the more intensive survey of aquatic fauna due to objections from a landowner.It appears to have no protective status other than the fact that it is includedwithin a large proposed NHA referred to as the Galway Bay Complex (Site code 0268)

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 5-5.6 °C in Januaryand 15-15.5 °C in July. The growing season (the period of mean daily air temperatures above6 °C) is 9.5 and as snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1200 mm, and the number of raindays (1 mm or more) is 10 months. Winds are mainly from the south-southwest. Mean annual hourlywind speeds are between 5 m/s and a maximum wind speed of50 m/s is estimated to occur once in 50 years. The daily duration of bright sunshine averages3.5-4 hours. Mean relative humidity is around 85% as on all Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8m (Carter 1992). Maximum wave heights (averaging once in 50 years) are 30-35 m(Couper 1983). Tides are semi-diurnal and the tidal range (MHWS-MLWS) at Galway is 4.5m (Admiralty Tide Tables). Sea temperatures are lowest in February and highest inAugust.

1 rf C y1 CO r o - h -OWY ffo. c J., o U o Bridge Lough J

Landscape and Geology The lagoon lies on Carboniferous limestone on the northwest side of the Burren area. Soils are described aslithosols, shallow organic soils and shallow brown earths. The area is karstic, withnumerous underground channels and surface drainage is low. The low areas surroundingthe lake are mostly J improved grassland and cereals.

Lake Topography The main area of the lagoon lies between the causewayand another road further to the west which runs parallel toit (Fig 12.2.1). The approximate dimensions of this part of the lagoon are 300 mfrom west to east, 200 m from north to south and total area is approximately 5 ha.An additional area extends beyond the road to the west giving the lagoon atotal area of approx. 7-8 ha. Most of the lake is shallow (<1 m) and substrate includes limestonebedrock, with detached rock and cobbles, and a thick layer of organic mudextending over most of the bed of the lagoon.

Hydrology There is no obvious freshwater inlet, but the lagoon lieson limestone bedrock and may be fed by underground channels. Spring tidespresumably enter the lagoon through the outlet channel in the east and itis possible that both freshwater and seawater enters through underground channels..

There is likely to be a daily tidal fluctuation inwater level of the lake during spring tides only, but a seasonal pattern may occur whereby waterlevels rise in the winter with the increased rainfall and storm surges, and gradually declinein the summer. Salinity and water quality Salinity levels are likely to be close to that ofseawater with hypersaline conditions occurring during summertime neap tides. There are obvious eutrophication problems partly due to the factthat the lagoon is not regularly flushed by seawater. The lagoon is small and shallowand therefore vulnerable to water quality problems.

2 Bridge Lough

12.2 AQUATIC FAUNA

BrendaHealy, GeoffOliver. Dept. of Zoology, University College Dublin. J 12.2.1 Methods

Environmental variables

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 ppt. precision). A photographic record was made of the site andlocal information sought concerning background and recent history.

Fainial Sampling. Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (I mm mesh) and close inspection ofstones and vegetation for one hour at each station. Faunal samples were preserved in70% alcohol and stored for subsequent sorting and identification. No light-traps or fyke nets were used in this lagoon.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present,common and abundant are purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of these werelarval or juvenile stages and difficult to identify with certainty. Some groups require adultmales for identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (e.g.Jaera spp., hydrobiids). All Diptera are identified to family level.

3 LJ

Bridgc Lough 0

12.2.2 Results EJ It was intended to select stations within the lagoon toreflect the influences of fresh and saline water and differences in vegetation and substrate but objectionsby the landowner made this impossible. 0 Bridge Lough was sampled only on the 23.vi.96 during thefirst part of the survey but some faunal species were recorded in the field near theoutlet during the second visit in 0 August.

Environmental Variables 0 Station A (OS 3405 1306) was located at the northeasterncorner of the lagoon below the ruins of a stone tower. Water depth variedfrom 0 cm to 50 cm, substrate 0 was mostly soft organic mud, with numerous large stones andsalinity measured 37%0. Station B was located at the southeastern corner where theoutlet runs under the causeway. Substrate was mostly rocks with soft organic mud, waterdepth was 0 cm - 0 I m and salinity measured 37 %o flowing from thelagoon. Station C (OS 3379 1285) was located at the westernend of the main body of the 0 lagoon. Substrate consisted of soft organic mud with limestone rocksof various sizes. Water depth was 0-50 cm and salinity measured 37%o. Salinity in the western section of the lagoon varied from3 1 - 38%0. 0 Fauna. The following assessment is based on a single collection madeat two stations. a The species recorded are listed in Table 12.2.1 Among 20taxa listed, 18 are identified to species. The list comprises 4 marine species, 5 poly-mesohalinespecies and 8 0 euryhaline species. (Table 12.2.2). Six of the species are listedas a lagoonal specialists in Britain (Davidson et al. 1991). Most of the recorded species occurred on the thick massesof Enteromorpha or 0 Chaetomorpha, or on stones on the soft substratum. Idotea chelipesand Cerastoderma glaucum were particularly abundant. A feature of the sitewas the 0 presence of a dark variety of the common beadlet anemoneActinia egttina, a species not found at any other lagoon site although it isknown to be tolerant of brackish conditions. The entire animal, including the beadlets was nearly black. 0 Table 12.2.2Ecological categories of the recorded taxa in Bridge Lough. L= lagoonal specialist according to Davidson et al. (1991).

Marine .actinia equina !)examine spinosa Littorina littorea 0 _Ilytilus edulis

Poly-mesohaline Arenicola marina Praunus flexuosus 0 Cerastoderma glaucum L Hvdrohia ventrosa L Limapontia depressa 0

0 4 0 130 L.W.M. 335 340 H.W.M.Kinvarra 10 km Fig. 12.2.1 Location Map of Sampling Stations in Bridge Lough, Knockakilleen, Co. Galway 0

Table 12.2.1. Fauna Recorded in Bridge Lough, Co. Galway. Juneand September, 1996. 0 ( ) = records from June.

Sampling Stations 0 A B C1) Porifera ---- (C) c T - -- -- Cnidaria 'Actinia equina 0 Turbellaria Nemertea Annelida I Arenicola marina (c) I _ 0 Crustacea _ Ostracoda Copepodal 0 Cirripedia _

MysidaceaPraunus flexuosus (+) j Isopoda Idotea chelipes (a) 0 Jaera sp. (+) _

j (+) Amphipoda Dexamine spinosa (+) ! Orchestia gammarella (+) 0 Tanaidacea

Decapoda Carcinus maenas j (+) + Palaemonetes varians (c) 0

Arachnids 1

Insects Thysanura 0 Ephemeroptera Odonata Plecoptera 0 Trichoptera Hemiptera

Coleoptera Enochrus bicolor I + 0 Cercyon littoralis +

Diptera Chironomidae (c) 1 Culicidae 0 Ephidridae Molluscs Prosobranchia Hydrobia ventrosa (c) 0

Pttorina littorea (c) e j i _

Opisthobranchia Limopontia depressa (+) ! ! I 0 Pulmonata, Bivalvia Cerastoderma glaucum --a Mytilus edulis e

Bryozoa Conopeum seurati + _ 0

Echinodermata ------Tunicatl Teleostei Pomatoschistus microps' _ 0 i Gasterosteus aculeatus -+ 0

0

0 + = present; o = occasional; c = common; a= abundant Bridge Lough

Euryhaline Idotea chelipesL Palaemonetes variansL Carcinus maenas Enochrus bicolor L Cercyon littoralis Conopeuin seurati Pomatoschistus microps Gasterosteus aculeatus

12.2.3 Discussion

The short list of species indicates an assemblage characteristic ofa lagoon in which medium to high salinities are maintained by frequent tidal incursions. The relatively high proportion of lagoonal specialists makes it particularly interesting. Thelake is very shallow and the species present are assumed to becapable of withstanding high temperatures in summer.

The fauna displayed some interesting features e.g. the abundance ofthe lagoonal specialist Idotea chelipes and the melanic anemone. It would repayfurther study, especially sampling at inland sites where the salinity may belower.

12.2.4 Threats

The lagoon appears to be highly eutrophic, partly due to the limited flow of water through the system.

It appears that at least one landowner has attempted to"reclaim" part of the lagoon. The owner of one area of the lake prevented anyfurther surveying

12.2.5 Evaluation

Bridge Lough is an artificial saline lake formed by constructionof a causeway across a sea inlet. Geomorphologically, therefore, it is not of internationalimportance.

It is situated in a limestone area and may befed by subterranean fissures, which would make it interesting at least from a geomorphological point ofview. However, it is largely artificial due to the construction of the causeway. The lake appears to be highly eutrophic and seems unlikelyto improve in the immediate future. Despite the fact that only one area was sampled, andvery briefly, some interesting species were recorded and there was a relatively high proportionof lagoonal species.. The lake is part of the proposed Galway Bay NHA(Site Code No. 0268) An evaluation of the fauna cannot be made based onthe limited amount of information collected. Further investigations should be carried out if possible.

5 u

Bridge Lough IJ

12.2.6 References and Additional Sources of Information 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department IJ Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. IJ Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. EJ Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. IJ Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird 0 Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady andN. Hyde 1974 National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha.. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. 0 Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp. IJ Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. IJ

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EJ 6 8 S m

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Plate t2-2.1View of the causeway and eastern area of Bridge Lough,Station A

m

Plate 12.2.2 View of the western area of Bridge Lough.

a J

Bridge Lough

12.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

12.3.1 Site Description(Fig. 12.3. 1)

This is a small silty lagoon on a low-lying promontorywith pasture to the north and south and wetland to the west. A causeway forms theeastern shore and seperates the site from the sea.

A stand of blackthorn woodland occurs close to the westernshore, where a dry stone wall runs along the edge of the lagoon.

Shores are generally shallow of slope. Emergent vegetation is restrictedto a small stand of Schoenoplectus in a sheltered bay in the southwest corner of the lagoon. Small areas of saltmarsh adjoin the lagoon along the northshore.

The pool which lies to the west is also abrackish water site. There is no major freshwater inflow stream. J

12.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects J 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 12.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

7 Dor,.nanL 5recIe5 coc`e5 S(acf-rnor er - SchoerioP(ec!'u5- uncu.s 9erc-diI FUCC[ne.(( assy rf,Grl 1l wr O © 0 C Fig. 12,31 _ ajn 0 0© Q Q OC=3 O a 0© C J U U U U C-] C-] C__j C__j C_J C_J C L_J L_J L U C C U U C_ N Travt ser- > 5 A - L.TA - Tc : Poi,1 '5 0 chavl9e marqlna ( iv1 ie9ef /Hi9 k Water Mdrk Fig 12.3 .2 Bridge Lough, Co.Galway: Shore-based Survey Sections Location of Transects and U

Bridge Lough 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as E the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and 0 the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was 0 generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample 0 area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during thecourse of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentagecover (using the Domin scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 0 9 76-90 % 8 51-75 % 7 34-50 % 0 6 26-33 % 5 11-25 % 4 4-10 % 0 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals D

0 8 Bridge Lough

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % IV 61-80 % III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communitieswas not available at the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall J Herb Fen' volume.

J Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report. J Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transectswere located at the outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course. J 7 Adjacent habitat and land use was described in general termsand dominant species recorded. J 2. Shore-based survey: J The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and landuse. The results are presented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of changeare marked on the site maps. J Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes. r1 J A brief site description was written for each lagoon.

r1 UI 9 0

Bridge Lough G

Constraints 0 Time. Restrictions on the time available in which to carryout this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was 0 insufficient time to carry out a full shore-based survey, b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0

Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0

Safety. Considerations of personal safety, in view of the factthat the surveyor was 0 working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores. 0 Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & a Wildlife Service

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is 0 recorded simply as `Enteromorpha'.

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University 0 College Galway and Michael Guiry, Professor of Botany, University CollegeGalway

Nomenclature 0

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of 0 charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation 0 This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey. 0 The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal 0 communities are taken into account, though particular importance is puton aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as 0 `Valuable', `Potentially Valuable' and `Not Valuable'. 0 10 Bridge Lough J

A `Valuable 'site is one that is shown to beof particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey. r, J A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

12.3.3 Results 1. Shore-based survey

Section A-B

Aquatic: Enteromorpha Filamentous algae Silt substrate with cobbles

Marginal:Unvegetated cobble and boulder substrate. c.2m Puccinellia maritima dominated saltmarsh vegetation with frequent Agrostis stolonifera and Juncus gerardii as Transect C. 1-2m stripon heavily poached substrate

Adjacent:Lolium perenne improved pasture

Section B-C (Transect A)

7 Aquatic: Filamentous algae Lj Silt substrate

Marginal:Schoenoplectus lacustris ssp tabernaemontani dominant with Epilobium hirsutum locally co-dominant, Agrostis stolonifera and Ranunculus sceleratus frequent. 20x8m

Adjacent:Agrostis stolonifera grassland with frequent Rorippa nasturtium- aquaticum. 10m Backing public road

7 lJ

II D Bridge Lough 0 Section C-D 0 Aquatic: Unchanged

Marginal:Festuca rubra - Juncus gerardii dominated salt tolerant vegetation as E Transect B.0.5-3m strip

Adjacent: Crataegus monogyna scrub on promontory E

0 Section D-E

Aquatic: Ruppia maritima- sparse 0 Filamentous algae

Marginal:Vegetation unchanged 0 Scattered boulders along shore

Adjacent:Unchanged 0

0 Section E-F

Aquatic: Unchanged a

Marginal:Unchanged a Adjacent:Low stone wall and public road 0 Section F-G (Transect B) 0 Aquatic: Ruppia maritima Enteromorpha Filamentous algae 0

I m dry stone wall runs moreor less parallel to shore c.5m out 100% cover of filamentous algae and Enteromorpha loughwardof wall 0 Patchy cover of Ruppia and filamentous algae landward of wall

MarginalSpecies-poor Puccinellia dominated salt tolerant vegetation.2-3m 0 Juncus gerardii- Festuca rubra dominated salt tolerant community. 4-6m Both communities with scattered cobbles and boulders

Adjacent:Prunus spinosa scrub with occasional Crataegusmonogyna 0

0 12

D Bridge Lough

J Section G-H

Aquatic: Filamentous algae - extensive

Marginal:Juncus gerardii - Festuca rubra dominated community as Transect B.0.3- J lm

Adjacent:1.5m dry stone wall with occasional Crataegus monogyna Lolium perenne pasture

Section H-I

Aquatic: Filamentous algae- sparse

J Marginal:Unchanged Adjacent:Unchanged J Section I-J

I lJ Aquatic: Unchanged

Marginal:Puccinellia dominant with Spergularia marina and Glaux maritima. 0.5-5m. Poached

Adjacent:Agrostis stolonifera- Trifolium pretense pasture

Section J-K

Aquatic: Filamentous algae- extensive

Marginal:Unchanged

Adjacent:Unchanged

Section K-L (Transect Q

Aquatic: Unchanged

Marginal:Puccinellia dominated salt tolerant vegetation with frequent Agrostis stolonifera and Juncus gerardii. 4-20m

Adjacent:Dactylis glomerata- Agrostis stolonifera - Trifolium repens - T. pratense grassland

13 Bridge Lough 0

2. Transects 0 Site: Bridge Lough Transect code: A

Location: Marginal swam Sample point: 1 Aquatic - 3m out Sample area: 25m2 (5x5) Substrate:Silt 0

Depth: 5 cm Salinit : 32arts per thousand NVC communit : ----- 0 Height (cm) Cover Total Plant 5 0 Filamentous algae 5

0 Description: Occasional small patches of free-fl oating filamentous algae only.Deep silt substrate. 0

Site: Bridge Lough Transect code: A D Location: Marginal swam Sample point: 2 Marginal Sample area: 80m2 10x8 Substrate: Silt 0 Depth: 0 cm Salinit : ----- NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- Agrostis stolonifera sub-community 0 Height cm Cover Total Plant 70 0 Schoeno lectus lacustris sstabernaemontani 90 30 E ilobium hirsutum 80 20 0 A rostis stolonifera 20 10 Ranunculus sceleratus 40 5 Tri lochinalustris 15 < 5 0 Nasturtium officinale 15 < 5 Rumex obtusifolius 50 < 1 Cheno odium rubrum 8 < I 0 Juncus bufonius 8 < 1 Carex otrubae 40 < 1 0

0 Descri tion: Schoeno lectus lacustris dominant with E ilobium hirsutumlocally co-dominant among freshwater associates. 8m. Backing A rostis stolonifera dam grassland with frequent Nasturtium officinale. 0

0

14 Bridge Lough

Site: Bridge Lough Transect code: B

Location: Open shore Sample point: 1 Aquatic - IOm out Sample area: 16m2 4x4 Substrate: Silt J Depth: 30 cm Salinit : 32arts per thousand

NVC communit : ----- Height (cm) J Cover Total Plant 100

Filamentous algae 100

Description: Complete cover of fiamentous algae only, extending back tod stone wall at 3m out from shore. J

Site: Bridge Lough Transect code: B Location: Open shore Sample point: 2 Aquatic - 3m out Sample area: 15m2 50 Substrate:Silt, cobbles

Depth: 10 cm Salinit : 28arts per thousand

NVC communit : ----- Height cm Cover Total Plant 25 Higher Plant 20

Ruis maritima 20 20

Algae 5

Filamentous algae 5 Enteromor ha < 1 J Description: Open cover of dominant Ruia. Olderarts of Ruis plants coated with algae, newer shoots moresparsely so. About 30- 40% of plants showing signs of recent growth, with some in bud, some flowering and some cominginto fruit. The remaining 60 - 70% shorter and completely coated balgae. J Backing low eat cliff- 50 cm.

15 u

Bridge Lough 0

Site: Bridge Lough Transect code: B 0 Location: Open shore Sample point: 3 Marginal Sample area: 20m2 10x2 Substrate: Peat, cobbles, boulders Depth: 0 cm Salinit ----- 0

NVC communit : Undetermined Height (cm) Cover (%) 0 Total Plant 95

Puccinellia maritima 15 90 0 Glaux maritima 15 < 5 Cheno odium rubrum 20 < 5 Juncuserardii 25 < 1 0

Bare substrate 5 C

Cobbles and boulders 5 0

Description. Dense cover of dominant Puccinel lia with tall associatesinspecies-poor saltmarsh strip. 3m. 0

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0 16 Bridge Lough

J Site: Bridge Lough Transect code: B Location: Open shore Sample point: 4 Marginal Sample area: 20m2 10x2 Substrate: Peat, bedrock, boulders

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height (cm) Cover (%) Total Plant 95

Juncuserardii 40 50 Festuca rubra 20 50 A rostis stolonifera 20 30 Cheno odium rubrum 15 < 5 Glaux maritima 15 < 5 Leontodon autumnalis 25 < 1 S er ularia marina 10

Bare substrate 5

Bedrock and boulders 5

Description: Juncuserardii and Festuca rubra co-dominant with A rostis stolonifera frequent and all otherspecies sparse. Ex posed bedrock and scattered boulderswith epi phytic :1 lichens and bryophytes. Sm. Backing Prunus s inosa woodland with occasional Cratae usmonona.

17 u

Bridge Lough 0

Site: Bridge Lough Transect code: C 0

Location: Open shore Sample oinV 1 Aquatic - IOm out Sample area: 16m2 (4x4) Substrate:Silt, cobbles 0 Depth.- 20 cm Salinit : 32arts per thousand NVC communit :----- Height cm Cover 0 Total Plant 100

Filamentous algae 100 G Enteromor ha < 1 0 Description: Complete surface layer of filamentous al al mat withsparse Enteromor ha restricted to submerged rocks. Same species at more or less same cover to shore. 0

0

0

0

0

0

0

0

0

a

0

D

0 18 J

Bridge Lough

Site: Bridge Lough Transect code: C Location: Open shore Sample point: 2 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height cm Cover (%) Total Plant 100

Puccinellia maritima 6 80 S er ularia marina 8 10 A rostis stolonifera 6 10 Juncuserardii 20 5 Juncus bufonius 6 5 Salicornia a 10 < 1 Trilochin maritima 15 < 1 Glaux maritima 8 < 1 Cheno odium rubrum 15 < 1 Leontodon autumnalis 15 < 1 Cochlearia an lica 6 < 1 Samolus valerandi 6 < 1

Description:Salt tolerant community dominated b extensive Puccinellia with frequent S er ularia and A rostis. Associated sp ecies sparse.25m. Backing dstone wall. Backing A rostis stolonifera- Trifolium re pens pasture.

19 0

Bridge Lough 0

12.3.4 Evaluation 0 `Not Valuable'

This is a shallow silty lagoon. Salinity was high (32parts per thousand) at time of 0 survey.

Ruppia maritima is the only higher plant species here andis restricted to a small area 0 landward of a dry stone wall that runs parallel tothe south western shore. 0 Elsewhere, filamentous algae has an almost complete cover over theentire site.

Marginal vegetation shows no notable variation. Puccinellia maritima dominated 0 saltmarsh forms a more or less narrow strip around mostof the site with Schoenoplectus lacustris ssp tabernaemontani locally dominant in a small bayin the south west corner of the site. a This is a very species-poor site of no botanical interest. 0 Further survey is not recommended. a

0

0

0

0

0

0

0

C

0

20 Bridge Lough

12.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

12.4.1 Site Description

Small, possibly hypertrophic, coastal brackish lake with causeway barrier andpossible blocked causeway seepages and/or subterranean or subaquatic karst channel connections tosea. Lake shore with peaty and organic-rich silty margins with extensive filamentousalgal growth, and with some limestone outcrops. Organic soil margins with Juncus gerardidominated swards where ungrazed. Bare mineral soil margins mostly saturated.

Subsites (see Fig. 12.4. 1)

1. Juncus erardi(M339129) Shallow peaty organic soil on limestone rock with bare shoremargin (c. 40 cm) and landward I gradient of plants: laminar and fibrous algae without vascular vegetation;Puccinellia marina, Juncus gerardi, Glaux maritima and Trigolichin maritima. Algal growthon water near shore. Amphipods very abundant. Calcareous pasture behind shore,near base of derelict windmill. Water near shore with salinity > 30 %o.

2. Limestone grass margin (M 336128) Rough grass on shallow soils with limestone pavement outcrops. Nearroad-bridge outflow from marshy area on west side of Lough.

12.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating thepresence of rare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

21 0

N 0

0 S 0

0

0

0

0

0

0

0

0

0

0

Fig. 12.4.1 0

Map of sampling sites (Carabidae and Staphylinidae) at Bridge Lough,Knockakilleen, Co. Galway

1 - Pitfall traps, S-vac 2 - Pitfall traps

0

0 Bridge Lough

Therefore, species were selected as indicators of conservation value if:(1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literatureas being local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant), (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It would bedifficult to defend a categorization of sites into any finer categories than this (see Fosteret al. (1992), for instance). Sites were not rated of average value if there were less than twoindicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and donot represent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.)or herbivorous assemblages (e.g. Lepidoptera). Different indicator speciesare likely to occur in spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will J probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginalareas were sampled, including vegetation dominated by Scirpus maritimus, J1117clls maritimus, Juncus gerardi andgrasses, as well as bare or poorly- vegetated areas of sand, silt or peat. Particular emphasiswas given to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 12.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as J 'S-vac' to distinguish it from the'D-vac' suction sampler) hasa suction pipe of 58 mm diameter

22 u

Bridge Lough 0

(0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample 0 were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- 0 freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were 0 used for the traps themselves. 0 TABLE 12.4.1. Details of sampling methods. 0

Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 0 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and plastic funnels; collars used 0 where cattle/horses occur Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; agitated soil floated in water 0

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are 0 representative of the sites, even if spring species may beabsent.

Variety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare 0 sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is 0 23 Bridge Lough

regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aguat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J. A. and Speight, M.C.D. (1991) Sites of internationaland national importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. hiogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : (1) Juncus gerardi area- S-vac suction sampler (3 viii 1996), c. 2 m2; (2) Juncus gerardi area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (23 vi- 3 viii 1996); (3) Limestone grass margin- 6 pitfall traps (8 - 28 ix 1996);

J Areas suitable for flotation or cobble search were not found.

7 1_J 24 U

Bridge Lough 0

Species were selected as indicators of conservation value if: (1)they have a restricted habitat 0 preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. 0

12.4.3 Survey Results a

Eleven species of carabid and thirty-one species of staphylinid wererecorded, one of which is regarded as an indicator species (Table 12.4.2). 0

Brundinia meridionalis occurred in all samples, but especially in theJuticus gerardi area 0 (Table 12.4.3). It has not been previously recorded from Ireland.Although it is not listed in Hyman and Parsons (1994) as rare or notable in GreatBritain, it appears to be rare or local in many parts of Europe (Porta 1926, Palm 1970, Benick &Lohse 1974, Mahler 1987, Koch 0 1989). B. meridionalis is a halophilous species, recorded from tidalrefuse and silty soils on the coast and also on inland saline soils in Austria andother countries (Steel 1970, Koch 1989). Tidally-undisturbed lagoons with stagnant water are favoured by this species- relatively large 0 populations were recorded on organic-rich soils with dense algal growthat three lagoons in this survey (also at Cloonconeen Pool and Lough Murree), butnot at other sites. 0 The staphylinid assemblage recorded from the Juncus gerardi area werepredominantly species which can occur in nutrient-rich agricultural soils (cf. Goodand Giller 1990) (Table 12.4.3). 0

0

TABLE 12.4.2 Carabidae and Staphylinidae (Coleoptera) recorded from Bridge Lough. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), andalso Booth 0 (1988) and Muona (1990) for two genera. 0 Species No. individuals

Carabidae Agonum marginatum (L.) 2

Bembidion guttula (F.) 1 Bembidion lampros (Hbst) 2 Bembidion ntannerheinu Sahlb. 4 Bembidion obtusum Serv. I Bembidion varium (OL) 2 0 Calathus melanocephalus (L.) l 1 vschirius globosus (Hbst) 3 Nebria brevicollis (F.) 1 0 Pterostichus madidus (F.) 1

Pterostichus nigrita (Payk.) 1 0

0 25 Badge Lough

TABLE 12.4.2 (cont.)

Staphylinidae

Aleochara bipustuloto (L) I Amischo analis (Gray.) 28 l nuscho rup-ofusca(Steph168

:I1701014S rugosus (F_) I

Atheta amplicollis (Muls. ReN II

Atheta elongatula(Gray.) I Brundinio nrer-idionalis (Muls. Rcv) 37 Indicator species

Carpelimus corticinus(Grav.) I

Drusilla canaliculata (F.) I Gvrohvprrus ongustatus (Steph.)

Ischnopoda atro (Gray) I Lesteva sicula Er. 3

Mycetoporussplendidus (Gray.) I Omalium laeviusculum GO. 2 Philonthuscarbonarius (Grav.) 2 Philonthus laminatus (Creutz.) Sepedophilus nigripennis (Steph.) 4

Stenus clavicornis (Scop.) I Stenus fuscipes Grav. 3 Stenus ossium Steph. 8

Tachinus signatus Grav. I Tachyporus chrvsornelinus (L.) 3 Tachyporus dispar (Payk.) 25

Tachyporushvpnorum (F.) I Tachyporus nitidulus (F.) 7

Tachyporus obtusus (L.) I

Tachyporus pusillus Grav. I

Tachyporus te,sus Er. I

Tinotus rnorion (Gray.) I

lantholinusglabratus (Grav.) I

Aantholinus longiventris Heer I

TABLE 12.4.3 Staphvlinid assemblage from Juticu.s gertzrdi area, Bridge Lough (S-vac J suction sample and pitfall traps combined). Abund. Cat. refers to categoryof relative abundance (no individuals. 1, 2-10, 11+).

Abund. Cat. Species No. Main biotope

Dominant lrnischa analis 28 Eu"topic, incl. nutrient-rich cultivated land Inn.vcha nrgrojusca 168 Eurytopic, incl. nutrient-rich cultivated land lirrnJrlir710 rarruhonalis 34 Halophilous, coastal 1 aclnporrr. dnpor 2 () Grassland u

Bridge Lough 0

TABLE 12.4.3 (cont.) 0 Intermediate 1 theta (Implicollis Eurmpic. incl. nutrient-rich cultivated land anguslatus Eurytopic. incl. nutrient-rich cultivated land I'Monthu.s carbonarms Eurytopic, incl nutrient-rich cultivated land 0 pllilonthus /aininalus Eurytopic, incl. nutrient-rich cultivated land Sepedophilus nigripennis Grassland S7enns clavicornis Eurytopic. incl. nutrient-rich cultivated land 0 Sfenuc Jincipes Mesotrophic/eutrophic marshes, riparian Slernrs ossirnn Eurt-topic, incl. nutrient-rich grassland Mchvporus chrvsomehino Eurytopic, incl. nutrient-rich cultivated land Tachvporus naidulus Eurytopic, incl. nutrient-rich cultivated land

Present .-t leochora hipustulata I Eurytopic, incl. nutrient-rich cultivated land I theta elongatula I Eurytopic, incl. nutrient-rich cultivated land 0 Corpehmus corticinus I Riparian

Ischnopoda atra I Riparian, freshwater Afvicetoporus splendidus I Eurytopic, incl. nutrient-rich grassland 0 Omahum laeviusculum 1 Halobiont, decaying seaweed Tachinus signatus I Eurytopic, incl. nutrient-rich cultivated land Tachvporus hvpnorum I Eurytopic, incl. nutrient-rich cultivated land Tochvporus obtusus I Eurytopic, incl. nutrient-rich cultivated land 0 Tach.Torus pusillus l Eurytopic, incl. nutrient-rich grassland

Tachvporus tersus I Grassland Tinotus morion I Eurytopic, incl. nutrient-rich cultivated land 0 Yantholinus globratus l Eurytopic, incl. nutrient-rich grassland \antholinus longiventris I Eurytopic, incl. nutrient-rich cultivated land 0

12.4.4 Evaluation 0 Of no conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional] 0

Scientific Argument for Rating The single indicator species recorded is tolerant of eutrophic conditions.The possible 0 hypertrophic state of the lake, and the nutrient-rich shore soil,is also indicated by the majority of staphylinid species which occur frequently in fertilized and manuredagricultural land (Table 12.4.3). A single indicator species, withoutan associated assemblage of more typical riparian 0 or halophilous species, is insufficient to give the site conservationstatus (Good and Speight 1991) 0

0

G

0

0

27 0 J

Bridge Lough

12.5 SUMMARY AND EVALUATION

Bridge Lough is not a coastal lagoon in the strictsense, but an artificial saline lake formed by construction of a causeway across a sea inlet.

The lake is part of the proposed Galway Bay NHA(Site Code No. 0268).

The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion.

Geomorphology Low Aquatic Fauna Moderate/High Vegetation None Ecotonal Coleoptera None

Geomorphology. Bridge Lough is a small (5 ha.) lake situated ina limestone area and may be fed by subterranean fissures, which would make it interesting at least froma geomorphological point of view. However, it is largely artificial dueto the construction of the causeway and the presence of a sluicedoutlet.. Based on geomorphology, Bridge Lough is regarded as of lowconservation value.

Aquatic Fauna The following assessment is based on small collections made attwo stations only. Among 20 taxa recorded, 18 are identified to species, ofwhich six are listed as a lagoonal specialists in Britain. Most of the recorded species occurred on the thick massesof Enteromor-pha or Chaetomorpha, or on stones on the soft substratum. Idotea chelipesand Cerastoderma glaucum were particularly abundant. A feature of the sitewas the presence of a dark variety of the common beadlet anemoneActinia equina, a species not found at any other lagoon site although it isknown to be tolerant of brackish conditions. The short list of species indicates an assemblage characteristic ofa lagoon in which medium to high salinities are maintained by frequent tidal incursions.The relatively high proportion of lagoonal specialists makes it particularly interesting.

29 u

Bridge Lough a

Despite the small number of samples analysed, the fauna appearsmoderately rich with 0 two interesting species. Bridge Lough is therefore rated as ofmoderate to high conservation value. Further investigations should be carried out if possible as amore detailed survey may indicate a higher rating. 0 Vegetation This is a shallow silty lagoon. Salinity was high (32%o) at time of survey. 0 Ruppia maritima is the only higher plant species here andis restricted to a small area landward of a dry stone wall that runs parallel tothe south western shore. Elsewhere, 0 filamentous algae has an almost complete cover over the entiresite.

Marginal vegetation shows no notable variation. Puccinellia maritima dominated 0 saltmarsh forms a more or less narrow strip around mostof the site with Schoenoplectus lacustris ssp tabernaemontani locally dominant in a small bayin the south west corner of the site. 0

This is a very species-poor site of no botanical interestfor higher plants. 0 Further survey is not recommended. a

Ecotonal Coleoptera 0 Eleven species of carabid and thirty-one species of staphylinid wererecorded, one of which is regarded as an indicator species. a Brundinia meridionalis occurred in all samples, but especially in theJuncus gerardii area. It has not been previously recorded from Ireland. Although it isnot listed as rare or notable in 0 Great Britain, it appears to be rare or local inmany parts of Europe. It is an halophilous species, recorded from tidal refuse and silty soils on thecoast and also on inland saline soils in Austria and other countries. Tidally-undisturbed lagoons with stagnant water arefavoured by 0 this species - relatively large populations were recorded on organic-richsoils with dense algal growth at three lagoons in this survey (also at CloonconeenPool and Lough Murree), but not at other sites. 0

The single indicator species recorded is tolerant of eutrophic conditions.The possible hypertrophic state of the lake, and the nutrient-rich shore soil,is also indicated by the majority 0 of staphylinid species which occur frequently in fertilized and manuredagricultural land.

A single indicator species, without an associated assemblage of moretypical riparian or 0 halophilous species, is insufficient to give the site conservation status. 0 Therefore, Bridge Lough is rated as of no conservation valuefor terrestrial ecotonal community. 0

30 J

Bridge Lough

Summary

Based on geomorphology, vegetation and ecotonal coleoptera, Bridge Lough isof very little interest. However, despite the fact that only onearea was sampled, and very briefly, some interesting species were recorded and there was arelatively high proportion of lagoonal species. Based on aquatic invertebrates the lake is of moderate conservationvalue as an artificial lagoonal environment. The lake appears to be highly eutrophic and seems unlikelyto improve in the immediate future. There has also been at least one attempt recently toinfill parts of it.

Overall, Bridge Lough is small and rated as of lowconservation value, but further investigations are encouraged. Proposal as an SAC is not recommended

9J

J

31 J

COASTAL LAGOONS IN THE REPUBLIC OFIRELAND

(VOLUME 111)

13. LETTERMULLEN POOL

BrendaHealy Geoff Oliver Pat Hatch Jervis Good

February 1997

n u

Prepared for the National Parks and Wildlife Service

(BioMar/Life) J

13 LETTERMULLEN POOL

CONTENTS

13.1 Study Area n J 13.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

J 13.2.1 Methods 13.2.2 Results 13.2.3 Discussion 13.2.4 Threats 13.2.5 Evaluation J 13.2.6 References 13.3 Vegetation Survey (Pat Hatch)

13.3.1 Site Description 13.3.2 Methods 13.3.3 Results Shore based survey Transect tables 13.3.4 Evaluation

13.4 Ecotonal Coleoptera (Jervis Good)

13.4.1 Site description 13.4.2 Methods 13.4.3 Results 13.4.4 Evaluation 13.4.5 References

13.5 Summary and Evaluation Lettermullen Pool

13 LETTERMULLEN POOL, Co. Galway.

7 OS Grid Reference: L 827 213, 1:50,000 Sheet No. 44 J Alternative names:

13.1 STUDY AREA

Lettermullen Poolis situated on the western shore of Lettermullen Island inwestern Connemara (Fig. 13.1.1). Six islands have to be crossed bybridges and causeways to reach Lettermullen. Golam Head is the final island in thisgroup which lies 500 metres J west of Lettermullen. The pool is usually regarded as alarge rock pool into which a freshwater spring runs and seawater enters on spring tides andduring storms. It can just as easily be regarded as a small coastal lagoon with a rock barrier.

Very little is known about the lagoon. It appears tohave no protective status.

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) 7Li The region experiences a mild oceanic climate with a smallannual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 5.5 °C in Januaryand 14.4 °C in July. The growing season (the period of mean daily air temperatures above 6°C) is 8.5 months and as snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1200 mm, and the number of raindays (1 mm or more) is 175-200. Winds are mainly from the southwest and west. Meanannual hourly wind speeds are between 5 and 6 m/s and a maximumwind speed of 50 m/s is estimated to occur once in 50 years. The daily duration of brightsunshine averages 3.5-4.0 hours. Mean relative humidity is around 85% as on all Irishcoasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 in (Carter 1992).Maximum wave heights (averaging once in 50 years) are 30-35 in(Couper 1984). Tides are semi- diurnal and the tidal range (MHWS-MLWS) at Galway is 4.5in (Admiralty Tide rl Tables). Sea temperatures are lowest in February and highest inAugust. J Landscape and Geology The Connemara region of Galway is a glaciated plain of rolling lowland with granite outcrops and Atlantic type blanket bog.The granite bedrock is impervious and drainage density is high. Soils otherthan peat are shallow podzols with very limited land-use capability (R.I.A., 1979). The areawas described by Haughton (1957) as a "wilderness of bare rock, glacial erratics,water and peat". Land surrounding the pool consists of small irregular fields ofsemi-improved pasture, bare rock, small peatbogs and wet heathland.

7 J 1 Illlaunel - An-ro lafha spi o qoc a ' ua (r Illaunro / A III S n ir LEiy ' An f011edn RU . TO ^: :. l aunpo C) . Y IInCh aft, snopeCerrlCKe _ Uey nit rn R IraA \ In Isie tro is h P X0he A III An r as. C akinna r 1 a ,b ,vI ! C Lemon Rou C ) AR Gu°I° 11 __ fni 0 MhiC in ,.i' . J Inishbarra V 1 1.040 n f$j(, , 3 Bearacha n ° ""AI nl Wirier Mar,'aj3 lougn Bun d I % An r0 eln y (/ n. ' p Glenn n a ell Curickad"'Agm Carralp Cal tine l See Ba y iin. asn SO h a I C Casheen Bayvan Ch aisln \ Gnaimmn l oco an " al ad ' e _ p Ice tarnlp an rma::C L w . J', (D a Sv ` -f' r(nQC n C mynn / aeawclou n n;onolpe'1_ z ` + l _ C i nla y 5 ^ .lJ Furnaceeusl J r a' 'lllaunCOln°an`Oeeln Cnallin ( LYrn .u / , VVV as' L G ^ O n V //n :, o/' ' lf' VJ I oYai ' o e an 1 i 1 I ,. ' I . r An aolach an 't' 1 lolyFOf "e II Gar na _ InfS - \ y }/ i .. Yell uaumnur°01 11 Tan , ' C mn ODlaln an Atonal Coonawilleen B ay . . Cleann Ii9Meume ina , n . vu Carrowroe ` " Cuan an Mhuilinnl S -''' \: C; e `.. - ' 'R m --, 'MA ' i J _,)) "" n Mhumnn an g n A w es - , ran Fhia 7 sf iipn a luc Tan Bna//at ' Wel A a, ° - h1 Knoc gnu" Cie q RibbedLough l0ugn_Nahd.daun Rua Theas stn h N '.. r .P ° M ock i H b ° l J Le rfTlU 4',. Bauyn ak,Il Lough y ra al, / RoRoi f I 10 L /hV M, l\ IochD bane na Cine r1 /I V R weu Holy `ic4( \ s ' I L ^ ` uey . l VICh : I \ Tratvbaunao ! uweaYn I m Ira Aelil -7I - ro lee / as r - arA / / t / .' ° well r n r n n's Bay \ ,, >o scn Chu, a n ) o%° III .n4 aer .li I Cuan Choresp.KiggauI- g ay \ v e e s 4/ / L'°rll RocA V Carol o Alan,, Y btAMUnlp , - D Rad Williams R°CAp e 1 awsy l au Cnlhn7 3 Ulan uic an Mama Uto AN MAd, an I a 0. _ - O O O C O O C C 0 O 'i O rC7 O 0 0 0 0 O D C J Lettermullen Pool

Lake Topography The lagoon is approximately one hectare in size, isup to 4 in in depth and substrate consists mostly of rocks of various sizes,some patches of bare bedrock, gravel and patches of organic silty sand.

J Hydrology Fresh water enters the pool through a small stream inthe east, through small groundwater springs at the edges of the pool andin direct rainfall.Seawater rl enters during spring tides and storms through two overwash areasin the west (Fig. 13.2.1) and from spray. LJ

There is no apparent daily tidal fluctuation in water levelof the lake even during spring J tides,but a seasonal pattern is likely, whereby water levels risein the winter with the increased rainfall and storm frequency, and gradually decline in thesummer. The peaty soils of the surrounding land would, however, through absorption andslow release of J water, affect the delivery time of both surface- and ground-waterflows to the pool. Salinity and water quality ri Salinity is likely to remain close to that of seawaterin J summer, with hypersaline conditions occurring during neap tides but tofall below 30%0 in winter. The peaty soils of the surrounding land would,however, through absorption and slow release of water, affect the delivery time ofboth surface- and ground-water flows to the pool. The prolonged flow of freshwaterto the pool during the "dry" months may result in lower salinities than might be expected. The surrounding land is relatively natural andeven grazing land is likely to receive only limited fertilizer applications. Water qualityappears to be high although quite a deep layer of organic silt has accumulated in the centralarea of the pool.

i J

2 Lettermullen Pool J 13.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin

13.2.1 Methods

Environmental variables Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Names and spellings usedare taken from the Discovery Series 1:50,000 O.S. map and grid referencesrefer to the centre of the site. At each sampling station the depth of water and substrate type were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o. precision). A photographic record was made of the site andlocal information sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used near stations A and B inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two J chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected by many environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are purely subjective, and absolute numbers vary between taxa.

3 r u

Lettermullen Pool 0

Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of these werelarval or juvenile stages tJ and difficulttoidentify with certainty. Some groups require adult males for identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (egJaera, hydrobiids). EI Finally, some soft-bodied groups were particularly difficult to identify whenpreserved (Nemertea). tJ All Diptera are identified to family level.

13.2.2 Results 0

Lettermullen Pool was sampled on 22.vi.96 during the first partof the survey, and from 25-26.viii.96 during the more intensive survey. Positions of thesampling stations 0 are shown in Fig 13.2.1

EI Environmental Variables

.As the pool is only 1 ha in area itwas not considered useful to record grid references of sampling stations, other than that at Station A 0 Station A (OS 8261 2142) was located at the northernend of the pool nearest to the road (Plates 13.2.1 & 4). A freshwater spring discharges intothe pool at this point and EI the area is slightly poached by cattle. Water depth variedfrom 0 cm to 1 m, substrate was mostly soft organic mud, withlarge stones, cobbles and gravel in varying proportions, and salinity measured 37 %o. 0 Station B was located on the western shoreline in anflattened area of rock, cobbles, gravel and coarse sand which appears to be regularly inundatedthrough overwash 0 (Plate 13.2.2). Water depth varied from 0- 1 m and salinity measured 35 %o. Station C was located on the southern shore of thepool, where a deep gully runs between the bedrock towards the coast (Plate 13.2.2). There isa series of deep pools 0 in this area between the pool and the high watermark on the coastline, and it seems likely that seawater enters the pool through the gully, butperhaps only on the highest of spring tides or during strong southwesterly gales. Substrate consistedof bedrock 0 and detached rocks of various sizes, cobbles and small pocketsof coarse sand. Water depth was 0-4 m and salinity measured 35%o D Station D was located in the central area of thepool in a Zostera bed. Depth varied from 0 cm -1 m, substrate was a deep layer of organic mudand fine silt/sand and salinity measured 35%o. 0

Fauna 0 The species recorded at the different stations, using all samplingmethods, are listed in Table 13.2.1. Among 52 taxa listed, 48 are identified tospecies; identification of remaining groups (Nemertea and larvae)willnot be attempted. Four species 0 (Arenicola marina, Praunus flexuosus, Melita palmata and Rissoa membranacea) are marine species with some tolerance of lowered salinity, three species(Littorina "tenebrosa", Balanus improvisus, and Cerastoderma glaucum) are poly-mesohaline, 0 fiveareeuryhaline(Hedistediversicolor,Idoteachelipes,Carcinus maenas, 0 4 J

J i

J J i

Fig. 13.2.1 Location Map of Sampling Stations in Lettermullen Pool, Co. Galway 100 m aprox !!! Table 13.2.1. Fauna Recorded at Lettermullen Pool, Co. Galway. Juneand September, 1996. () = records from June.

Fauna Sampling Stations( L.T. = light-trap) A L.T.A B L.T.B C L.T.C D L.T.D Porifera Cnidaria Aurelia aurita (+) Laomedea angulata + + + + Turbellaria Nemertea Nemertea sp. 1 + Nemertea sp. 2 + Annelida Arenicola marina + + Hediste diversicolor ? Janua pagenstecheri + Spirorbidae indet. + + + + Tubificoides benedii + Crustacea Ostracoda Copepods + Cirripedia Balanus improvisus +

Cumacean 1 Mysidacea Praunusflexuosus c 75 c 11 c 2 c 50 Siriellajaltensis 1 Isopoda Idotea baltica + + I. chelipes a 11 a o Amphipoda Dexamine spinosa + + + Melita palmata + + Orchestia gamarella + Tanaidacea Tanais dulongi + DecapodaCarcinus maenas + + + + Palaemon elegans o 0 Arachnids Insects EJ Thysanura Ephemeroptera Odonata 0 Plecoptera Trichoptera Hemiptera Coleoptera Enochrus bicolor + Diptera Chironomidae + + Molluscs Polyplacophora Lepidochitona cinerea + + Prosobranchia Bittium reticulatum + Gibbula umbilicalis + Hinia incrassata + Littorina littorea + L. "tenebrosa" a + c + Nucella lapillus + 1 Patella vulgata + + Rissoa membranacea c a c Skeneo sisplanorbis o c

+ = present; o = occasional; c = common; a= abundant; F = fyke net lJ t Table 13.2.1. cont.. Fauna Recorded atLettermullen Pool, Co. Galway.June and September, 1996.

l 1 rPrords from June I Sampling Stations( L.T. = light-trap) lJ Fauna A L.T.A B L.T.B C L.T.C D L.T.D

OpisthobranchiaElysia viridis + Pulmonata o c Bivalvia Cerastoderina glaucum c o Mytilus edulis o Bryozoa Alcyonidium mamillatum + + Conopeum seurati + J Bowerbankia gracilis + Walkeria uva +

EchinodermataAmphipholis squamata + Luidia ciliaris c Paracentrotus lividus 1

Tunicata Ascidiella aspersa + + A. scabra +

A. virginiata + + Botryllus schlosseri + + + J Clavelina lepadiformis + + Teleostei Conger conger F, I Ctenolabrus rupestris F, I 4 + o Gasterosteus aculeatus + 1 + Molva molva F, 1 Pollachius pollachius F. I F, 2 J

+ = present; o =occasional; c = common; a = abundant;F = tyke net tj Lettermullen Pool a Conopeum seurati, Gasterosteusaculeatus) andone (Enochrus bicolor) is considered as oligohaline in this report.. Five species(Idotea chelipes, Enochrusbicolor, Littorina "tenebrosa ", Cerastoderma glaucum and Conopeum seurati)are listed as 0 lagoonal specialists in Britain (Davidsonet al. 1991). Most species were distributed throughout the pool but some whichare common 0 intertidallyin thearea(Patellavulgata,Littorinalittorea,Nucellalapillus, Paracentrotus lividus, Luidia ciliata) were restricted to the seaward stations,and some herbivores and euryhaline species (Balanusimprovises, Idotea chelipes,Elysia 0 viridis, Enochrus bicolor) were found only at the landward stations (Aand D) which may receive more freshwater, or in Zostera beds. 0 13.2.3 Discussion

The fauna was distinctly marine EJ and most of the recorded speciesprobably occur in nearby shallow coastalwater. There was, however,a significant brackish element which included five lagoonal specialists,three of which have been recordedin previous 0 years and their populations are therefore wellestablished. The salinityon both sampling occasions in 1996 was at least 34%o but 28%o was recorded in July1990 when the lagoonal specialists Hydrobia ventrosa and Palaemonetes varianswere 0 present (not recorded in 1996). The salinityalmost certainly falls to lower levelsin winter and the highsummer levels in 1996 may have been exceptional.The presence of marine fish not normally associated with isolated saline waters (lingand conger) 0 suggests that large influxes ofseawater occur occasionally. The hydroid Laomedea angulata, which is associated with Zostera, isconsidered to be a rare species in Britain and there appears to be only one record of it in Ireland,but a recent coastal survey has shown thatit actually occurson many of the Zostera beds investigated. This site, andthe North Slob,are the only known localities in Ireland of 0 the controversial "species" Littorinatenebrosa..

13.2.4 Threats 0

Small numbers of cattle graze the surrounding land but have little impacton the pool. 0 The local landowner is attempting to provide a campsite in the vicinity of thepool but no special facilities have been providedso far. 0 13.2.5 Evaluation

cJ Lettermullen Pool isa natural rock lagoon andistherefore of international importanceon the basis of geomorphology alone.. 0 Geomorphologically, this isa large, supralittoral rock pool whichcan also be classified as a lagoon with a rock barrier, receiving seawater by occasional overwash. 0 The pool contains a mixed flora of marine algae, Zostera andcharophytes, and both hard and soft substrates, providing a wide range of habitats for fauna ina small area. 0

5 0

0 Lettermullen Pool

The aquatic fauna is distinctly marine, most species probably occurringon nearby shores, but there is also a significant element of brackishspecies, including five lagoonalspecialistsone of which,Littorina"tenebrosa ",iscurrentlybeing investigated. The pool and its fauna are known to localmarine biologists but no proper survey of the fauna has been carried out previously.

A interesting hydroid was recorded.

In conclusion, Lettermullen Pool has high conservation value as aunique type of lagoon but the area is remote and unlikely to needspecial conservation measures in the immediate future. Its designation as a proposed SAC is recommended.

13.2.6 References and Additional Sources of Information

Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Haughton, J.P. 1957. Physiography and Climate. In: Meenan, J. &D.A. Webb.(eds.) A View of Ireland. Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 23 5-23 8. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp.

6 M

Plate t-3.2.1 View of Lettermullen Pool looking west, Station A

Plate 13.2.2 View, of Lettermullen Pool looking east, Station B(foreground) D (middle distance) and C (on the left) a,

Plate 13 23 View of Lettermullen Pool looking south

r

Plate 13.2.4 View of Lettermullen Pool looking southeast from StationA J Lettermullen Pool 7 J 13.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims

The aim of this survey is to describe the vegetationof each site in such a wayas to facilitate its subsequent assessment and consideration for legal protection. n U 13.3.1 Site Description (Fig 13.3. 1)

Lettermullen Pool is a small isolated lagoon situatedon a rocky headland and immediately bordered by high groundon all sides but the north east.

This high ground is predominantly covered with maritime grassland andcliff communities and drops more or less steeply to the lagoon'sshores. These are low peat cliffs with occasional stretches of exposed bedrock.

The rocky substrate drops away fairly steeply from all shoresbut the northern, except where where a narrow bedrock shelf straddles the mouth ofthe southern bay.

A small area of wet grassland lies beyond the lowcliff and outcrops of the north eastern shore and is associated with the pool's only inflowchannel, which enters here. According to local knowledge this narrow channel isa third access point for seawater during winter storms, in addition to the two overwash points.Scirpus maritimus occurs in this channel up to approximately 250 meteres backfrom the lagoon.

There is no emergent vegetation.

13.3.2 Methods

Two survey methods were employed in thecourse of fieldwork: 1. Transects 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 13.3.2.

Each transect ran from the aquaticzone, through adjacent marginal areas, to the adjacent habitat. Aquatic and marginalareas were sampled using quadrats or releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, insome cases, on the depth of soft substrates. A

7 0

0

0 KEY : Expo5ed bedrock 0 -L.o,^/ earih c(ily Dominantyecie5 code;: 0 J-mar- unci{5 Mdri f i",q5 0

0

0

0

0

0

0

a

0

0

0

0

0

Fig. 13.3.1 L P4_)m A((n PQoL \leil P ion 0

0

0 J

I

C rtirL1lr' \ Overwash \

point 1

TA

'j.r. .

Overwash ~~ point TA-TC = Transects A - R = Points of change in aquatic or marginal vegetation

Figure 13.3.2Location of Transects and Shore-based Survey Sections, Lettermullen Pool, Co. Galway Lettermullen Pool 0 transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point. 0

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage 0 cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover. 0 At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel 0 survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. 0

At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. 0 The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the 0 loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, a high water mark, as this is difficult to establish atmany sites.

In the marginal areas through which each transect passed, homogeneousstands of a vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For 0 example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0 Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the 0 transect.

Representative examples of every marginal community encountered during the course 0 of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentage cover(using the Domin 0 scale) and the calculation of frequency for each species:

Cover/Abundance Values 0 Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0 Domin. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 0

8 0 J Lettermullen Pool n 6 26-33 % 5 11-25 % U 4 4-10 % r1 3 <4 % -many individuals J 2 <4 %-several individuals 1 <4 % -few individuals

Frequency Values Frequency of each species within the total number of samplesis expressed as follows: 7 U Frequency V 81-100 % IV 61-80 % III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. J Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The results arepresented here as 7 descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres n UI 9 Lettermullen Pool a

out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes. 0

A brief site description was written for each lagoon. 0 Constraints 0 Time. Restrictions on the time available in which to carryout this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was 0 insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0

Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0

Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications 0

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is 0 recorded simply as `Enteromorpha'.

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University 0 College Galway and Michael Guiry, Professor of Botany, University CollegeGalway

Nomenclature 0

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of 0 charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading E of each site according to specified criteria and recommendations forfurther survey. 0 The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not 0

10 0 J n Lettermullen Pool u a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'.

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection.

1 A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey. LA

A `Not Valuable 'site is one that is shown tobe of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

n 13.3.3 Results u n 1. Shore-based survey

LJ Section A-B (Transect A)

Aquatic: Filamentous algae- extensive Corallina officinalis - patchy J Chondrus crispus- sparse Bedrock substrate

Marginal:Exposed bedrock shore- slope c.35-90 degrees

J Adjacent:Maritime cliff community dominated by Festuca rubra with frequent Armeria maritima, Crithmum maritimum, Plantago maritima, Plantago coronopus, Spergularia rupicola, Silene maritima and crustose and fruticose lichens

11 Uttermullen Pool 0

Section B-C (Transect B) 0 Aquatic: Ruppia cirrhosa- patchy Zostera marina - patchy Filamentous algae- patchy 0 Enteromorpha - sparse Polysiphonia elongata- sparse Codium tomentosum- sparse 0 Lomentaria clavellosa- sparse 0 Bedrock substrate forming shallow shelf with sand, gravel, cobbles and boulders 0 Marginal:Low rock and earth cliff to 20cm

Adjacent:As A-B plus occasional Limonium humile and Raphanus maritimus 0

Section C-D 0

Aquatic: Ruppia cirrhosa- dense bed beyond algae Zostera marina - patchy cover amongst Ruppia D Filamentous algae- dense cover up to lm out Enteromorpha - sparse amongst filamentous algae Chondrus crispus - sparse amongst filamentous algae 0 Lamprothamnium papulosum

Bedrock substrate 0

Marginal:Unchanged 0 Adjacent:Unchanged 0

Section D-E D Aquatic: Ruppia cirrhosa- patchy Zostera marina- sparse Filamentous algae- as above Enteromorpha- as above Chondrus crispus- as above 0

Marginal:Unchanged 0 Adjacent:Unchanged 0

0 12 Lettermullen Pool

Section E-F J Aquatic: Ruppia cirrhosa - patchy Zostera marina - very sparse J Filamentous algae - as above Enteromorpha - as above Chondrus crispus - as above

Bedrock substrate with cobbles and boulders in shallow sheltered bay J Marginal:Unchanged

J Adjacent:Unchanged

Section F-G J Aquatic: Ruppia cirrhosa - dense bed beyond algae Zostera marina - patchy cover amongst Ruppia J Filamentous algae - patchy cover up to Im out Corallina officinalis - patchy cover up to Im out Chondrus crispus - sparse up to Im out

Marginal:Bedrock shore with lichens

Adjacent:Festuca rubra - Potentilla anserina grassland. Grazed

Section G-H

Aquatic: Unchanged

Marginal:Juncus maritimus dominated salt tolerant community as Transect C forming 1-2m strip along shore. Juncus gerardii and Glaux maritima frequentwith few sparse associates.

Adjacent:Unchanged

Section H-I

Aquatic: Species and cover as before plus Lamprothamnium papulosum

Marginal:Bedrock shore - average slope c.45 degrees - with occasionalemergent Juncus maritimus tussocks

Adjacent:Unchanged

13 0

Lettermullen Pool a

Section I-J 0 Aquatic: Unchanged

Marginal:As G-H 0

Adjacent:Unchanged 0 Section J-K 0 Aquatic: As F-G

Marginal:Bedrock shore with lichens 0

Adjacent:Public road Backing to Ulex gallii - Erica cinerea heath 0

Section K-L (Transect Q 0

Aquatic: Ruppia cirrhosa - dense bed c. 10m out, increasingly sparseto landward Zostera marina - patchy cover amongst Ruppia, increasingly sparse to 0 landward Filamentous algae - increasing cover to landward Lamprothamnium papulosum - patchy cover up to 5m out 0

Silt substrate

Marginal:Dense Juncus maritimus cover with patchy Juncus gerardii and sparsesalt tolerant associates. lm 0 Adjacent:Festuca rubra - Potentilla anserina grassland 0

Section L-M 0

Aquatic: Ruppia cirrhosa - dense bed beyond algal belt Zostera marina - patchy cover amongst Ruppia 0 Filamentous algae- dense cover up to 1 m out Lamprothamnium papulosum- beyond Ruppia belt 0 Bedrock substrate with silt and cobbles

Marginal:Bedrock shore with lichens 0

Adjacent:Bedrock outcrop with lichens 0

0

14 0 J

Lettermullen Pool J

J Section M-N

Aquatic: Ruppia cirrhosa - dense bed beyond algal belt Zostera marina - patchy cover amongst Ruppia Algae as A-B in narrow strip to 2m out

Bedrock substrate

Marginal:Unchanged

Adjacent:Unchanged

J Section N-O

Aquatic: Ruppia cirrhosa - open bed beyond algal belt J Zostera marina - patchy cover amongst Ruppia Lamprothamnium papulosum - patchy cover amongst Ruppia Filamentous algae - dense cover up to lm out Chondrus crispus - sparse amongst filamentous algae

Marginal:Unchanged

Adjacent:Unchanged

Section O-P

Aquatic: Species unchanged Lamprothamnium restricted to shallow bays Chondrus restricted to steeply sloping bedrock shores

Bedrock substrate with silty patches

Marginal:Bedrock shore with occasional stretches of c.50cm peat cliff Peat cliff areas backing to Juncus maritimus dominated community as Transect C. 1-2m

Adjacent:Festuca rubra - Potentilla erecta grassland

15 Lettermullen Pool 0

Section P-Q 0 Aquatic: Ruppia cirrhosa - dense bed beyond algal belt Zostera marina - patchy cover amongst Ruppia Filamentous algae --dense cover to 2-5m out 0

Marginal:30-50cm peat cliff 0 Adjacent:Unchanged 0

Section Q-R 0

As A-B plus sparse Codium 0

Section R-A D

Aquatic: As B-C 0 Marginal:Steep bedrock shore with crustose, foliose and fruticose lichens -slope c.80 degrees 0 Adjacent:Maritime cliff community as A-B 0

0

0

0

0

0

0

0

16 J

Lettermullen Pool

2. Transects J Site: Lettermullen Pool Transect code: A Location: Seawater access point Sample point:1 Aquatic - 2m out Sample area: 20m2 10x2 Substrate: Bedrock

Depth: 10 - 40 cm Salinit : 34 arts per thousand NVC communit :----- Height cm Cover 100 7 Total Plant LJ

Corallina officinalis 4 65 Filamentous algae 6 30 Chondrus cris us 5 > 1

Description: Open cover of Corallina with patchy filamentous algae onsteeply sloping J substrate.

J

Site: Lettermullen Pool Transect code: A Location: Seawater access point Sample oint: 2 Aquatic - 50cm out Sample area: 10m2 10x1 Substrate: Bedrock

Depth: 0 - 10 cm Salinit : 34 arts per thousand J NVC communit :----- Height cm Cover %) J Total Plant 100

Filamentous algae 100

Description: Dense cover of filamentous algae only. Backing rocshore (slope c.75 degrees) dominated b Festuca rubra with Armeria maritima, Crithmum maritimum, Planta o maritima, Planta o coronous, S er ularia ru icola, Silene maritima and ru icolous crustose and fruticoselichens.

17 0

Lettermullen Pool 0

Site: Lettermullen Pool Transect code: B Location: Shallow rock shelf Sample point:1 Aquatic - 25m out 0 Sample area: c.300m2 whole stand Substrate: Bedrock, sand Depth: 30 cm (average) Salinit: 34 arts per thousand 0 NVC communit :----- Height cm Cover Total Plant 60 0 Hi her Plant 20

Ruis cirrhosa 40 15 0 Zostera marina 40 5

Algae 40 0

Filamentous algae 10 40 0 Codium tomentosum 3 < 1 Pol si honia elon ata 4 < 1 Lomentaria clavellosa 4 < 1 0 Enteromo ha 10 < 1

Description: Open filamentous algae cover with Ruis and Zostera occurring in occasional 0 small dense beds (average area c.5m2 and in more opencover. Other al al species sparse. Within Ru is - Zostera beds average cover c.80% Ruis - 20% Zostera. 0 This is a raised area of bedrock running across thenorthern end of the bay at the southern seawater overwash point. The substrate drops away sharply tonorth and south. Backing to 50cm eat cliff. 0 Planta o corono us, Planta o maritima, Armeria maritima, Silenemaritima frequent.

0 Site: Lettermullen Pool Transect code: C Location: Sheltered bay Sample oint:1 Aquatic - IOm out Sample area: 25m2 5x5 Substrate: Silt Depth: 30 cm Salinit 3 arts per thousand NVC communit :----- 0 Height cm Cover Total Plant 100 Higher Plant 100 0

Ruis cirrhosa 50 90 Zostera marina 60 10 0

Algae 10 0

Filamentous algae 10 0 Description: Dense Ruis bed with occasional patches of Zostera and filamentous algae.

0

18 0 Lettermullen Pool

Site: Lettermullen Pool Transect code: C Location: Sheltered bay Sample oint: 2 Aquatic - 3m out Sample area: 25m2 5x5 Substrate:Silt, cobbles

Depth: 20 cm Salinit : 35arts per thousand NVC communit :----- Height cm Cover Total Plant 100 Higher Plant 5 J Ruis cirrhosa 30 < 5 Zostera marina 30 < 5

Algae 90

Filamentous algae 70 Lam rothamnium a ulosum 10 20 J Description: Filamentous algae dominant with sparse Ruis and Zostera. Lam rothamnium in fairly dense patches, locally dominant within 2m of shore. J

Site: Lettermullen Pool Transect code: C Location: Sheltered bay Sample oint: 3 Marginal J Sample area: 10m2 10x1 Substrate: Peat Depth: ----- Salinit: ----- NVC communit : Undetermined Height cm Cover Total Plant 95

7'1 L. Juncus maritimus 50 80 Juncuserardii 25 10 Glaux maritima 10 5 Cochlearia an lica 4 5 Aster triolium 25 < 1 Planta o maritima 10 < 1 Limonium humile 25 < 1

Description. Dense Juncus maritimus cover with patchy Juncuserardii ands arse salt tolerant associates. 2m. Grading to Festuca rubra - Potentilla anserina grassland. 10m. Backing public road.

19 Lettermullen Pool 0

13.3.4 Evaluation 0 `Valuable'

Lettermullen is a small rocky site of high salinity (34-35parts per thousand at time of 0 survey) and interesting species composition. 0 The presence of marine algae could be expected at sucha site and several species are found here. Corallina officinalis is abundant. Chondrus crispus, Lomentaria clavellosa, Codium tomentosum and Polysiphonia elongata all occur at varying degreesof 0 frequency.

Zostera marina could also be expected and is abundant here.Particularly interesting is 0 the occurrence of these marine species with abundant Ruppia cirrhosaand with Lamprothamnium papulosum, a rare charophyte for which this is anew site. 0 Lamprothamnium was known from only three Irish sites before thissurvey took place. Its presence at Lettermullen is alone reason enough to regardthe site as valuable. Lamprothamnium is very locally abundant in shallow areas close tothe northern shore 0 and was also found in deeper water (> l m)by grapnel survey from the southern and western shores. 0 The distribution of species is also interesting in that adistinct zonation occurs along the steeper, rocky shores with algal species forming a 1-2mwide belt below the shore with a dense mixed Ruppia and Zostera bed beyond. a

Marginal vegetation is restricted due to the rocky, steep-sided natureof the site. No emergent species occur here. Juncus maritimus over species-poor salt tolerant a vegetation is the dominant community. 0 Lettermullen Pool is a good representative of an isolated (i.e.having no permanent connection to the sea) highly saline lagoon. Species composition andshore zonation are interesting, species diversity and abundance are high and arare charophyte occurs 0 here.

A full aquatic survey is recommended.

0

0

0

0

0 20 0 J

Lettermullen Pool J

13.4 ECOTONAL COLEOPTERA

7 J.A. Good Ph.D MIEEM FRES, j Terrascope Environmental Consultancy, Riverstick, co. Cork r( 13.4.1 Site Description LJ A < 0.5 ha rock-pool lagoon, with mostly rocky shore,and small rock pools occurring above lagoon water level at date of visit. Eroded peat andcoarse shell-sand cliff-banks and coarse sand / pebble shingle and someJuncus maritimus occurred. However, noneof these areas were represented by more than a few metres of shore-line.

Subsites (see Fig 13.4. 1)

1. Barrier shingle (L 827213) Cobbles on coarse sand, bank creating barrier to sea tonorth-west of site. Ligia oceanica abundant.

13.4.2 Methods

Site Rating using Indicator Species J Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with J relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the

21 0

0

0

0

0

0 N

0 100 m aprox.

0

0

0

0

0

0

Fig. 13.4. 1Map of sampling sites (Carabidae and Staphylinidae)at Lettermullen Pool, Co. Galway D 1 - Cobble search 0

0

0

0 J

Lettermullen Pool

non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if there were less than two indicator

species present (see argument in Good and Speight 1992). .

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 13.4.1 For each site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine (referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) has a suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample U were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Sampling involved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water.

22 Lettermullen Pool 0

Sampling was carried out during latesummer and early autumn (late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated 0 with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring speciesmay be absent. 0

0 TABLE 13.4.1. Details of sampling methods.

0 Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels; collars used where cattle/horses occur 0 Cobble samples Cobbles turned 0.5- 2 in 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth 0 burrow casts observed; agitated soil floated in water Ground search Search of bare soil (< 50% 1 1 hour 0 vegetation cover) during warm weather without rain 0 Variety of sampling techniques Several techniques will always givea more robust picture of the fauna of a site, 0 because any weather- or site-affected bias inone technique will be compensated by other sampling methods. Some sites did notpossess suitable habitat (peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground searchor cobble search. This is 0 regarded as an absence of habitat, rather thanan unavailable sampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the 0 site.

Flooding of pitfall traps 0 Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tidesto place and lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the 0 survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of whichtwo were sorted. There was only one site (Aughinish which has a spring/neap water level variation of>I m) where flooding 0 limited trap results to onlyone set. 0

0

23 0 J

Lettermullen Pool

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the J National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. n Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. J 14: 48-53.

Methods used at this site

(1) Barrier shingle- cobble search (50 cobbles, 6 vii 1996).

No carabids or staphylinids were recorded.

13.4.3 Survey Results

J There is insufficient habitat at this site to allow comparativesampling, so a full survey was not undertaken.

13.4.4 Evaluation

Of no conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating

There is insufficient habitat to allow comparative sampling, and probablyto support a viable assemblage of ecotonal Coleoptera. Furthermore, the nature of the substrateand abundance of J Ligia indicate that the margins of the site are regularlydisturbed by sea flooding.

24 J

Lettermullen Pool

13.5 SUMMARY AND EVALUATION

Lettermullen Pool is a small (1ha) natural rock lagoon and istherefore of J international importance based on the Habitats Directive.

The pool and its fauna are known to local marinebiologists but no proper survey of the fauna has been carried out previously.

The following table shows the conservation value of the lake based on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion. J

Geomorphology High Aquatic Fauna High/Exceptional Vegetation Exceptional Ecotonal Coleoptera (No appropriate habitats)

Geomorphology

J Geomorphologically, this is a large, supralittoral rock pool (c.l ha.)which can also be classified as a lagoon with a rock barrier, receiving seawaterby occasional overwash.

As a coastal lagoon of unusual type Lettermullen is ratedas of high conservation value.

Aquatic Fauna

Among 52 taxa listed, 48 are identified to species; includingfive species (Idotea chelipes, Enochrus bicolor,Littorina "tenebrosa ",Cerastoderma glaucum and Conopeum seurati) which are listed as lagoonal specialists. Most species were distributed throughout the pool but some whichare common intertidallyinthearea(Patellavulgata,Littorinalittorea,Nucellalapillus, Paracentrotus lividus, Luidia ciliata) were restricted to the seaward stations,and some herbivores and euryhaline species (Balanus improvisus, Idotea chelipes, Elysla viridis, Enochrus bicolor) were found only at the landward stationswhich may receive more freshwater, or in Zostera beds. The pool contains a mixed flora of marine algae, Ruppia,Zostera and charophytes, and both hard and soft substrates, providing a wide range ofhabitats for fauna in a small area.

25 0

Lettermullen Pool 0

This one of only two known localities forLitiorina " tenebrosa". An interesting hydroid (Laomedia angulata ) was recorded. 0

Based on the high number of species including lagoonal specialists.Lettermullen is rated as of high to exceptional conservation value. 0

Vegetation 0 Lettermullen is a small rocky site of high salinity (34-35%0 at time of survey) and interesting species composition. 0

The presence of marine algae could be expected at sucha site and several species are found here. Corallina officinalis is abundant. Chondrus crispus, Lomentaria D clavellosa, Codium tomentosum and Polysiphonia elongata all occur at varying degrees of frequency. 0 Zostera marina could also be expected and is abundant here.Particularly interesting is the occurrence of these marine species with abundant Ruppia cirrhosaand with Lamprothamnium papulosum, a rare charophyte for which this is anew site. 0

Lamprothamnium was known from only three Irish sites before thissurvey took place. Its presence at Lettermullen is alone reason enough to regardthe site as valuable. 0 Lamprothamnium is very locally abundant in shallow areas close tothe northern shore and was also found in deeper water (>I m) bygrapnel survey from the southern and western shores. 0

The distribution of species is also interesting in that adistinct zonation occurs along 0 the steeper, rocky shores with algal species forming a 1-2mwide belt below the shore with a dense mixed Ruppia and Zostera bed beyond.

Marginal vegetation is restricted due to the rocky, steep-sided natureof the site. No emergent species occur here. Juncus maritimus over species-poor salt tolerant vegetation is the dominant community. 0

Lettermullen Pool is a good representative of an isolated (i.e.having no permanent connection to the sea) highly saline lagoon. Species composition andshore zonation 0 are interesting, species diversity and abundance are high and arare charophyte occurs here. The site is therefore rated as of exceptional conservationvalue 0 A full aquatic survey is recommended.

Ecotonal Coleoptera 0

No carabids or staphylinids were recorded. 0 There is insufficient habitat to allow comparative sampling, and probablyto support a viable assemblage of ecotonal Coleoptera. Furthermore, the nature of the substrate and abundance of 0 Ligia indicate that the margins of the site are regularlydisturbed by sea flooding.

0

26 0 J

Lettermullen Pool J

Lettermullen Pool is therefore rated as of no conservation valuefor terrestrial ecotonal community.

Summary J In conclusion, Lettermullen Pool has high conservation value as aunique type of lagoon. J The aquatic fauna was distinctly marine, most species probably occurringon nearby shores, but there is also a significant element of brackishspecies, including five lagoonal specialists one of which, Littorina " tenebrosa ", iscurrently being investigated. The pool and its fauna are known to localmarine biologists but no proper 7 survey of the fauna has been carried out previously. lJ Species composition and shore zonation of the vegetation are interesting,species diversity and abundance are high and a rare charophyte wasrecorded.

Based on geomorphology, aquatic fauna and flora Lettermullen Pool israted as of high conservation value.

Designation as a proposed SAC is recommended.

27 COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME

u Brenda Healy Geoff Oliver t__I Pat Hatch 7 Jervis Good J

I February 1997 7

LJ

tJ

Prepared for the National Parks and Wildlife Service

J (BioMar/Life) j

J 14. LOCH TANAI, Co. Galway 7 CONTENTS L] 14.1 Study Area

14.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

14.2.1 Methods 14.2.2 Results 14.2.3 Discussion 14.2.4 Threats 14.2.5 Evaluation 14.2.6 References

14.3 Vegetation Survey (Pat Hatch)

14.3.1 Site Description 14.3.2 Methods 14.3.3 Results Shore based survey Transect tables 14.3.4 Evaluation rl J 14.4 Ecotonal Coleoptera (Jervis Good) r-

1I uI 14.4.1 Site description 14.4.2 Methods 7 14.4.3 Results L1 14.4.4 Evaluation 14.4.5 References

14.5 Summary and Evaluation

7

ui . Loch Tanai J7'

J 14. LOCH TANAI, Co. Galway. OS Grid Reference: L 950 305, 1:50,000 Sheet No. 45 Alternative names: Lough Nacrimina

14.1 STUDY AREA

General features Loch Tanai is situated in western Connemara, 5 km northof Costelloe and 6 km south of Camus. The lake is shallow and lies inan area of lowland peat, which receives seawater through a channel in the peat which connects itto Loughaunavneen, a small bay of the larger Camus Bay (Fig. 14. 1. 1).The description of this lake as a lagoon may be contentious but it is includedas a good example of a type of lagoon, rarein a J European context, but characteristic of parts of thewest coast of Ireland, especially in Connemara, which are permanent, shallow, brackish, with restrictedtidal influence due to the presence of a "barrier" of peat. These "peat"lagoons are of particular interestas 7 very little appears to be known about any aspect ofthe functioning of brackish lagoons situated in acid peatbogs. Very little is known about the lake. Itappears to have no protective status but lies close to the proposed Kinvarra Saltmarsh NHA (Site code2075) n J Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompaniedby rain and strong winds. The mean daily air temperature is 6°C in January and15°C in July. The growing season (the period of mean daily air temperatures above 6 °C)is 8.5 and as snow and frosts are rare, some plant growth is possible in winter months.Annual rainfall is 7 approximately1300 mm, and the number of rain days (1 Li mm or more) is 175-200. Winds are mainly from the southwest. Mean annual hourlywind speeds are 5-6.0 m/s and a maximum wind speed of 30-35 m/s is estimatedto occur once in 50 years. The daily duration of bright sunshineaverages 3.5-4.0 hours. Mean relative humidity is around 85% as on all Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with J median wave heights of 1.5-3.0in and frequent cyclonic depressions which produce large waves, inshore breakers commonly exceeding8 in (Carter 1992). Maximum wave heights (averaging once in 50 years) are 30-35 (Couper1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS)at Kilkieran is 4.2 m (Admiralty Tide Tables). Sea temperaturesare lowest in February and highest in August. U Landscape and Geology The Connemara region of Galway is a glaciated plain of rolling lowland with granite outcrops and Atlantictype blanket bog. The granite bedrock is impervious and drainage density is high. Soilsother than peat are shallow

1 n

E map Tanai Loch of locality showing 000 50 1 of Section 14.1.1 Fig. u G n u u n

lSI6,bh an ails r 0 I BdIIInIIBa n ah.-Dove, Ban` ; ; E Rua Chearyiru An u U CARRAROE>-- GIeJM. ' sd, h ,' 1"1 peueogr 4 u

0 0

utnOl -6rulny Ciona;th K ,rte akinna 0 -

; Ro an a;.. and Rossroe 811oe

0 Aw rdAJn n uuiva

E

0 eolle 0

euunnet - C vyeuo ; 0 /1. 0 0 u

r1 _ +S h a5ria0 Cn sAan n u 0 h eaLgi nj end our-w4l uei? anop.I L-1

r1 0 u

oOurwun,raayi IpH n ru rW r _Cidnnacni u Ay u n r L L 17 L L uoihas ;o I 0C 000 .1o tpo-1 ieutij E. diu' rllnle-)ol'uin',oys

u J1I Loch Tanai

7 podzols with very limited land-use capability (R.I.A. 1979). The areawas described by Haughton (1957) as a "wilderness of bare rock, glacial erratics,water and peat". Land surrounding the loch consists of small irregular fields ofsemi-improved pasture, bare rock, small peatbogs and wet heathland. Lake Topography The lagoon is an `L' shape, rotated 90 degrees, measuring approximately 300 m from north to south, 500 m fromwest to east and covers about 12 ha. Water depth is fairly uniform 50 - 120cm over most of the lake with shallower margins, substrate consists mostly of unconsolidated peat with patches ofrocks of various sizes, associated especially with scattered rocky islands. It seems likely that the lake is not as naturalas it appears, but that it may have been at least partly created through an earlier phase of peat cutting.The channel connecting J the lake to the tidal area of Loughaunavneen appears tohave been cut deliberately but n it is not known at what date or whether itwas cut recently in an attempt to drain the J lake and surrounding land or at an earlier date inorder to cut peat. Hydrology Freshwater enters the lake through a stream in the southwest,through the slow release of groundwater from the saturated peat andin direct rainfall. J Seawater appears to enter during spring tides and perhaps onthe higher neap tides. No tidal fluctuation in water level of the lake wasrecorded during the survey, but a seasonal pattern is likely (Plate 2.14.4), whereby water levels risein the winter with the increased rainfall and storm frequency, and gradually decline inthe summer. The peaty soils of the surrounding land would, however, through absorptionand slow release of water, affect the delivery time of both surface-and ground-water flows to the pool. Salinity and water quality Salinity levels are likely to be in the upper rangethrough most of the year, with a rise during the summerand decline in the winter. The peaty soils of the surrounding land would, however, affect the variation.The prolonged flow of freshwater to the pool during the "dry" months mayresult in lower salinities than might be expected. On the other hand, winter stormsmay result in a higher volume of seawater entering the lake and raising salinity levels at atime when they might be expected to fall. The surrounding land is relatively natural and even grazing landis likely to receive only limited fertilizer applications. Water qualityappears to be high although quite a deep layer of organic silt has accumulated insome areas of the lake and there is a dense growth of pond weed and filamentous algae in the southwestwhere the freshwater stream enters. A certain amount of pollution of the lakehas occurred through the dumping of cars and refuse in the part of thelake closest to the road.

7 u-

2 r-1 Loch Tanai Ll

7 1_J 14.2.AQUATIC FAUNA Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin

14.2.1 Methods r"1 U Environmental variables n Water depths were measured using a plumbline from an inflatabledinghy. J The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site.

At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., I %o precision). A photographic record was made of the site andlocal information sought concerning background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), rZ sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for U one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. 7 Li Fyke nets were used at stations A and D inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and n returned alive whenever possible. J Limitations of Sampling Methods and Species Determination All sampling methods used in the surveyare affected by many environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often with a different samplingmethod. The results of

3 r

Loch Tanai

the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna and thenon-random distribution u within the water column. Abundance categories ofpresent, common and abundant are purely subjective, and absolute numbersvary between taxa. n Several faunal groups were sorted and distributedto specialists. Standard keys were used to identify remaining specimens, butmany of these were larval or juvenile stages and difficult to identify with certainty. Somegroups require adult males for identification and these were often not available dueto low population density and the u limited number of individuals collected in the time available (e.g.Jaera, hydrobiids). Finally, some soft-bodied groupswere particularly difficult to identify when preserved. l All Diptera are identified to family level. n 14.2. 2 Results u

Loch Tanai was sampled on the 22.vi.96. during the firstpart of the survey, and from 22-24.viii.96 during the more intensivesurvey. 0

Five sampling stations were selected in the laketo reflect the influences of substrate, 0 and freshwater/seawater inflows. Fig. 14.2.1 shows the positionof these sampling stations in the lagoon. 0 Environmental Variables Station A (OS 9521 3057) was locatedat the eastern end of the lake nearest to the road (Plate 14.2. 1). There are freshwaterseepage zones on the shoreline in this area, 0 and this part of the lake has been usedas a dumping area for cars and refuse. Water depth varied from 0 cm to 60cm, substrate was fine silts and peat, with occasional stones and gravel. Salinity measured 32-34%o 0 Station B (OS 9515 3057)was located in the small bay slightly to the northwestof Station A (Plate 14.2. 1). A small springenters at this point, water depth was very 0 shallow ( 0- 15 cm) substrate consisted of soft unconsolidated peat andsalinity measured 11 %o u Station C (OS 9492 3061)was located in the northwest corner where the channel which leads to Camus Bay enters the lake. Water depthwas 0 -1 m, substrate was mostly unconsolidated peat and salinity measured28 - 32 %o. 0 Station D (OS 9488 3036) was locatedat the bay at the southwestern end of the lake where a stream enters. Depth varied from 0cm -1 m, substrate was unconsolidated peat with a dense growth of pond weed and filamentousalgae and salinity measured 14 0 -27%o.. Station E (OS 9498 3052) was locatedon the shoreline of the largest rocky island in E the lake. substrate consisted of granite rocksand boulders with pockets of coarse granite sand and organic silt, water depth varied from0 -1 m. and salinity measured 34%o 0

0

4

n i Loughaunavneen (leading to Camus Bay) n 310 J

J

Camus 6 km

u 7 tJ J n Costelloe 5 km

LJ 7 J

300

947

Fig.14.2.1Location Map of Sampling Stations in Loch Tanai, Co. Galway. 7 L1

L u

Table 14.2.1. Fauna Recorded at Loch Tanai. June and August1996. a Sampling Stations ( L.T. = light-trap) AL.T.AB L.T.B C L.T.C D L.T.DE L.T.E Porifera 0

1 Cnidaria_ Aurelia aurita + 1 +

Turbellaria ! IJ Nemertea Nemertea + Annelida_ Arenicola marina o a Hediste diversicolor + + 1 + tj _ Polychaeta indet._ + Tubificidae indet. + Crustacea IJ Cirripedia Mysidacea Praunusflexuosus a >100 a a 100 a >100 a c100 Isopoda Lekanesphaera hookeri + 4 + + + 3 0 Idotea chelipes + + + + + 1 Ligia oceanica + + Amphipoda Caprella acanthifera EJ Corophium volutator + + Dexamine spinosa + + Melita palmata + + IJ Orchestia gammarella + +

Tanaidacea i Decapoda Carcinus maenas + F, 1 0 Palaemonetes varians o 3 Arachnida Hydracarina 1 Insecta E Ephemeroptera Odonata Plecoptera 0 Trichoptera

Hemiptera ! Coleoptera Enochrus bicolor + 0 Diptera Chironomidae + +

I Mollusca Prosobranchia Hydrobia ulvae + + E Hydrobia ventrosa + + + Littorina saxatilis + + + 12 +,111 Rissoa membranacea + C + j + IJ Opisthobranchia Akera bullata e 6 + + ; + I

Pulmonata I Bivalvia iCerastoderma glaucum a o + + tJ Musculus discors + + +

+ ! + _ Mytilus edulis + I + + IJ Bryozoa_ Conopeum seurati + i +

Echinodermata__ _ _ i -- ---.-- -.-'- + + + Tunicata 'Ascidiella scabra I I . _- U --- -- Clavelina lepadiformis + + + + _ Teleostei Anguilla anguilla F, 3 Gasterosteus aculeatus t o 2 o 2 o 0 1 ! Magi Iidae Ia I -_- ___._ -- - -,-- - - Platichthysflesus - r --- S yngnathus typhle 1I - - - 0 + = present; o = occasional; c = common; a= abundant; F = fyke net tJ J

Loch Tanai

I aura The species recorded at the different stations, using all samplingmethods, are listed in Table 14.2. 1. Among 36 taxa listed, 30 are identifiedto species. The list (excluding marginal species) comprises 10 marine species, 9 poly-mesohaline, 9 euryhalineand one oligohaline species. Hydracarina are assumed to be limnic. (Table14.2.2). Six species are listed as a lagoonal specialists in Britain (Davidsonet al. 1991). J Differences in salinity between stations, which varied from 11%o atB to 32-34%o at A and E, did not have a noticeable affect on faunaldistribution. Enochrus bicolor, for example, were taken in both the lowest and highest salinities.Equally, habitats with different substrates and vegetation were not characterised by differences infaunal composition or diversity. In spite of the soft substrate, muchof which was unconsolidated peat, burrowing forms were relatively well represented throughout the lake and were not more abundant or diverse at stationswith more sand or silt (e.g. A). The most abundant species at all stations was Praunusflexuosus. Cerastoderma glaucum was represented by both adults and juveniles.

J Table 14.2.2Ecological categories of the recorded taxa in Loch Tanai (excluding marginal species). L = lagoonal specialist according to Davidson elal. (1991).

Marine Aurelia aurita Dexamine spinosa Caprella acanthifera Hydrobia ulvae Akera bullata Musculus discors Mytilus edulis Ascidiella scabra Clavelina lepadiformis Syngnathus typhle

Poly-mesohaline Arenicola marina Praunusflexuosus Melita palmata lJ Corophium volutator Hvdrobia ventrosa L Littorina saxatilis Rissoa membranacea Cerastoderma glaucum L Mugilidae

Euryhaline Hediste diversicolor Lekanesphaera hookeri L Idotea chelipes L Palaemonetes varians L Carcinus maenas Conopeum seurati L Anguilla anguilla Gasterosteus aculeatus Platichthvs flesus 7 L-- Oligo-mesohaline Enochrus bicolor L

Limnic Hvdracarina

5 Li

Loch Tanai 0

0 14.2.3 Discussion 0 The fauna is moderately rich and the species predominantly brackishwith a high proportion of lagoonal specialists. The assemblage typifiesan open system receiving r- regular influxes of seawater but also considerableamounts of freshwater. The fauna is characteristic of lagoons with sea inlets and water in theupper to middle salinity range which allows persistence of lagoonal specialists suchas Cerastoderma glaucum and Hydrobia ventrosa together with marine species suchas tunicates, Akera bullata and l 0 Syngnathus typhle. Akera bullata and Syngnathus typhlewere not found at any other site. None of the recorded species can be described as rare in Ireland. tJ

14.2.4 Threats 0

There appear to be no threats to the lake otherthan the fact that the shore is used as a refuse dump and there is possible eutrophication in the southwestof the lake. tJ

14.2.5Evaluation 0 Loch Tanai is a natural saline lake in peat. Althoughnot a lagoon in the strict sense because the barrier is neither sedimentaryor of rock, it presents many of the characteristics of lagoons e.g. it is shallow and brackish, andcontains a high EJ proportion of lagoonal specialist species. It could be describedas a lagoon with a peat barrier. 0 It is an unusual type of saline lake formed inpeat, with a long, possibly artificial, tidal inlet. It is one of several similar lakes in the peatland area south of Camus Bay all of EJ which have long inlets and may have similar origins. Theirhistory and hydrology are worth further investigation. a Loch Tanai, and the other similar lakes in thearea, appear to be unknown to marine biologists and their communities have not, therefore, been investigated. tJ Faunistically, the lake is a good example ofa lagoon with salinity in the middle to upper range. A high proportion of the species recorded arelagoonal specialists. There were some unusual species present, e.g. Akera bullata and Syngnathustyphle, but no 0 rare species were recorded.

As very little appears to be known aboutany aspect of brackish lagoons in acid 0 peatlands, it is recommended that the other similar lakes inthe vicinity be investigated and consideration be given toa proposed SAC designation for the total area in which they lie. IJ

0

0

6 Loch Tanai

J 14.2.6 References and Additional Sources of Information

Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N. C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. J Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Haughton, J.P.1957. Physiography and Climate. In: Meenan, J. & D.A. Webb.(eds.) A View of Ireland. Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird J Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) J in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152 U pp.

7 J

Plate 14.2.1View of Loch Tanai looking west from Station A.

D

ri

LI

Plate 14.2.2Area of Loch Tanai close to the road used asa rubbish dump.

i LJ

I

1 i J

Plate 14.2.3View across Loch Tanai from Station B, looking southwest..

n iJ-

r7

7 Plate 14.2.4 Large granite rock in Loch Tanai showing evidenceof variation in water level. .. : Loch Tanai

14.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork .

I Aims

The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

14.3.1 Site Description(Fig. 14.3.1)

This is a low-lying area of heath and bog withfrequent rock outcrops.

Exposed bedrock forms much of the shoreline, particularly on smallpromontories, with long stretches of peat shore between forming low cliffsin places. Marginal areas are typically narrow with more extensive Juncus maritimus wetland aroundbayheads and associated inflows.

The only stands of tall emergents are narrow Phragmites bedsfringing the two largest islands.

The main freshwater inflow joins the lagoon from the southwest. There are several smaller streams and flushes, mostly to the south.

The outlet channel runs from the north west corner ofthe lagoon.

A public road runs along part of the north easternshore.

tJ

14.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey.

1. Transects:

The locality of these is shown in Fig. 14.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described. 7 The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases,on the depth of soft substrates. A

8 u

G

0

0

0

KAY n _Exposes( bedrock L.ow peaf c(v vowlirldlil codes: u 3 rvlcll'ItIP1 0

0

0

0

0

0

0

41 0

C

C

Fig. 14.3. - Cfah on U N

A U ^o TO E TA c CD D (12 O 0O

P T 0 Q

TG 5 `fA -TG : R A-U: Poinf5ochdl/ein CIVaL7 is /rrturqina(vefafion

J-I

Fig. 14. 3.2 Loch Tanai, Co.Galway: Location of Transects and Shore-based Survey Sections 0

Loch Tanai 0 One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. Theaverage height and percentage 0 cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover. n

At the aquatic end of each transect a grapnelwas used to attempt to locate additional species and these were recorded. Whereno additional species were found the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic 0 survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. D At each aquatic sample point measurementswere taken of salinity (using a hand refractometer) and water depth. The nature of the substratewas also recorded. The position of each aquatic samplewas recorded as `x metres out, meaning so many 0 metres out from the shore. For the purposes of thissurvey, the shore' is defined as the marginal vegetation line. Thiscan be both the loughward edge of a swamp andthe loughward edge of saltmarsh vegetation with 50metres of bare sand between it and 0 the waters edge at time of survey. Itwas felt that this location method was more accurate and made sample areas more re-locatable thanone related to, for instance, 0 high water mark, as this is difficult to establishat many sites.

In the marginal areas through which eachtransect passed, homogeneous stands of EJ vegetation were identified and sampled using quadratsor releves. Sample area was generally 100m2 for single species and particularly species-poorstands and 16m2 for other stands. Sample shape varied accordingto the shape and size of the stand. For 0 example, many marginal standswere narrow strips. All plant species in the sample area, their average height and percentage coverwere recorded. 0 Salinity and water depth were measured and recordedwhere appropriate. Salinity readings for marginal swampswere taken at the midway point along that part ofthe transect. 0

Representative examples ofevery marginal community encountered during the course of the survey were sampled using British National VegetationClassification (NVC) 0 methods for the purpose of subsequent classification.This involved the taking of five quadrats in each community and the recording ofpercentage cover (using the Domin scale) and the calculation of frequency for each species: 0

Cover/Abundance Values Each species in a sample is givena percentage cover value according to the Domin a scale as follows: G Domin.. 10 91-100% 9 76-90 % 8 51-75 % C 7 34-50 % 6 26-33 % 5 11-25 % 0 4 4-10 % n 9 Loch Tanai

3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals

Frequency Values Frequency of each species within the total number of samplesis expressed as follows: J Frequency V 81-100 % 7 IV 61-80 % J 111 41-60 % r, II 21-40 % J I 1-20 % Note: The NVC volume covering saltmarsh communitieswas not available at the time 7 U of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume. 7 LJ Representative examples were used as there was insufficient time tosample each 7 community at every site where it occurred in this way.The resulting data are lJ presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

7 The locations of transects within each sitewere selected to represent the degree of J variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transectswere located at the outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and landuse. The results are presented here as descriptive notes, divided into sections along the shore accordingto changes in floristics, substrate and/or adjacent habitat. These points of changeare marked on the u site maps.

Aquatic vegetation was surveyed byuse of the grapnel and by means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes. Lf A brief site description was written for each lagoon..

10 Loch Tanai 0

Constraints 0 Time. Restrictions on the time available in which tocarry out this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was u insufficient time to carry out a full shore-basedsurvey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). u

Resources. No boats were available for survey purposes. This isone reason why this n is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was L working alone, meant that, with one exception,no dives were undertaken. This is the second reason for the restriction of thissurvey, in the main, to the lagoon shores. E Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & E Wildlife Service n Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is 0 recorded simply as `Enteromorpha'.

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University 0 College Galway and Michael Guiry, Professor of Botany, University CollegeGalway

Nomenclature C

Scientific names of vascular plants in this reportare in accordance with Clapham, Tutin 0 & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a briefsummary of the survey findings for each site, a grading of each site according to specified criteria and recommendations forfurther survey. El The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, thepresence of rare species and whether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance isput on aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as G `Valuable', `Potentially Valuable' and Not Valuable'. o

11 J

1 Loch Tanai 1J 7 t__J A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this survey indicates may be of interest and which may prove to be valuable following further survey.

A Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged. J 14.3.3 Results J 1. Shore-based survey

Section A-B (Transect A)

Aquatic: Ruppia sp. - dense beds Zostera marina - patchy cover amongst Ruppia Filamentous algae - extensive n Enteromorpha - patchy s Fucus c.f. vesiculosus - patchy, to 1-2m out only Fucus sp. - patchy, to 1-2m out only Phyllophora psuedo ceranoides- sparse Lamprothamnium papulosum- patchy cover amongst Ruppia 7 I Peat and silt substrate with frequent cobbles U Marginal:Juncus maritimus tussocks with species-poor understorey of patchy Agrostis stolonifera and sparse salt tolerant associates. 1-10m Vegetated strip interrupted by occasional bedrock outcrops

Adjacent:Ulex gallii - Molinia caerulea- Erica cinerea heath with frequent Daboecia cantabrica

U Section B-C

Aquatic: Unchanged

Marginal:Bedrock and boulder shore with lichens

Adjacent:Ulex gallii - Molinia caerulea- Calluna vulgaris heath

12 u

Loch Tanai E Section C-D (Transect B)

Aquatic: Ruppia sp.- patchy E Zostera marina- patchy Filamentous algae- extensive 0 Lamprothamnium papulosum- sparse

Silt substrate 0 Marginal: Juncus maritimus tussocks with patchyAgrostis stolonifera andsparse salt tolerant associates. 25-30m 0

Adjacent:Bog vegetation dominated by Moliniacaerulea, Calluna vulgaris, Sphagnum spp. EJ

Section D-E 0

Aquatic: Ruppia sp.- sparse, low growing Filamentous algae- extensive 0

Marginal:As C-D. 8-10m EJ Adjacent:Heath as B-C and bog vegetationas C-D 0 Section E-F 0 Aquatic: Ruppia sp.- sparse, low growing Filamentous algae- extensive Lamprothamnium papulosum - sparse EI Peat and silt substrate with cobbles C Marginal:Bedrock shore with lichens Adjacent:Heath as B-C 0

Section F-G n

Aquatic: Ruppia sp.- sparse Filamentous algae- extensive E Fucus c.f vesiculosus- patchy Fucus sp.- patchy

Marginal:Juncus maritimus salt tolerant community.lm

Adjacent:Unchanged C

EI 13 J

Loch Tanai

Section G-H

Aquatic: Ruppia sp. - very sparse Zostera marina - sparse Filamentous algae- extensive Fucus c.f vesicu losus -dense cover to1-2m out Fucus sp. - dense cover to 1-2m out

Marginal:Bedrock shore with lichens

Adjacent:Unchanged

rI J Section H-I ri LJ Aquatic: Ruppia sp. - fairly dense patches beyond fucoid belt Zostera marina- sparse Filamentous algae- extensive Fucus c.f vesiculosus- sparse Fucus sp. - sparse Lamprothamnium papulosum- sparse

Marginal:Unchanged

Adjacent:Unchanged

Section I-J

I LJ Aquatic: Ruppia sp. - dense patches Zostera marina- sparse Filamentous algae- extensive Fucus c.ff, vesiculosus- dense cover to 1-2m out Fucus sp. - dense cover to 1-2m out ri Lamprothamnium papulosum- sparse LJ Marginal:Juncus maritimus salt tolerant community. 1-2m

Adjacent:Unchanged n s Section J-K Aquatic: Unchanged

Marginal:Lichenous bedrock shore with occasional patches of Juncus maritimus salt tolerant community

Adjacent:Unchanged

14 u n Loch Tanai J

Section K-L 0 Aquatic: Ruppia sp.- dense patches Zostera marina- very sparse t-7 Filamentous algae- extensive Lamprothamnium papulosum- dense patches

Marginal:Unchanged EJ

Adjacent:Unchanged EJ

Section L-M Ei Aquatic: Ruppia sp.- sparse, low growing Filamentous algae- extensive 0 Silt substrate 0 Marginal:Juncus maritimus salt tolerant community. Up to c.50mat bayhead, 1-2m strip elsewhere Ei

Adjacent:Unchanged 0

Section M-N EJ Aquatic: Ruppia sp.- dense beds beyond fucoid belt Zostera marina- sparse amongst Ruppia Filamentous algae- extensive Ei Fucus c.f vesiculosus- dense cover to 1-2m out Fucus sp. - dense cover to 1-2m out Lamprothamnium papulosum Ei

Bedrock substrate with gravel and cobbles E

Marginal:Lichenous bedrock shore with occasional patches of Juncus maritimussalt tolerant community C

Adjacent:Unchanged V

n U

Ei 15 n J

Loch Tanai

7 Section N-O Li Aquatic: Ruppia sp. - dense beds Filamentous algae - extensive Lamprothamnium papulosum

Coarse gravel substrate with cobbles

Marginal:Juncus maritimus salt tolerant community forming 1-2m strip along shore Backing to 1.5m peat cliff

Adjacent:Unchanged 7 Li Section O-P

Aquatic: Ruppia sp. - fairly dense cover beyond fucoid belt Zostera marina - sparse amongst Ruppia J Filamentous algae - extensive Fucus c.f vesiculosus - dense cover to 1-2m out Fucus sp. - dense cover to 1-2m out Lamprothamnium papulosum - patchy cover amongst Ruppia

Marginal:Rocky shore as M-N

Adjacent:Unchanged

7 Section P-Q LA Aquatic: Zostera marina - patchy cover Filamentous algae - extensive Fucus c.f vesiculosus - cover unchanged Fucus sp. - cover unchanged

Marginal:Unchanged rl J Adjacent:Unchanged

Section Q-R

Aquatic: As O-P Zostera now fairly dense n Marginal:Unchanged u- Adjacent:Unchanged

16 U

Loch Tanai 0

Section R-S Ei

Aquatic: Ruppia sp.- fairly dense Filamentous algae- extensive 0 Lamprothamnium papulosum

Peat, silt and gravel substrate with cobbles and boulders 0

Marginal:Juncus maritimus salt tolerant community forming 2-8mstrip along shore Backing to 1.5m peat cliff Ei

Adjacent: Heath as B-C and bog vegetationas C-D a

Section S-T (Transect C) Ei

Aquatic: Ruppia sp.- patchy, low growing 0 Filamentous algae- extensive

Silt substrate Ei

Marginal:Juncus maritimus community with patchy Agrostis stoloniferaand sparse associates to c.20m with occasional small patches of Puccinellia 0 maritima dominated vegetation G Adjacent:Ulex gallii- Calluna vulgaris - Erica cinerea dominated heath 0

Section T-U Ei Aquatic: Ruppia sp.- dense beds Zostera marina- patchy cover amongst Ruppia Filamentous algae- extensive 0 Enteromorpha- sparse Lamprothamnium papulosum- sparse 0 Peat, silt and gravel substrate 0 Marginal:Unchanged

Adjacent:Unchanged 0 n u

E 17 rl Loch Tanai U

2. Transects Site: Lough Tanai Transect code: A Location: Outlet to sea Sample point: 2 Aquatic - 2m out Sample area: 16m2 4x4 Substrate: Peat, silt, cobbles

Depth: 30 cm Salinit : 32 parts per thousand NVC communit :----- Height (cm) Cover Total Plant 100 Hi her Plant 80 a Ruis s p. 40 70 Zostera marina 60 10

Algae 60

Filamentous algae 50 Fucus c.f vesiculosus 40 5 J Fucus s p. 25 < 5 Ph llo hors psuedo ceranoides 8 < 1 Lam rothamnium papulosum 15 10

Description: Dense Ruis bed and frequent Zostera growing through and between patchy cover of filamentous algae with Lam rothamnium occurring where Ruis density lower. J Fucoids restricted to submerged rocks close to shore. Some Ruis plants in bud, some in flower. J Site: Lough Tanai Transect code: A Location: Outlet to sea Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ---- NVC communit :Undetermined Height (cm) Cover Total Plant 100

Juncus maritimus 70 80 Agrostis stolonifera 10 25 Glaux maritima 6 < 5 Aster tripolium 20 < 1 Triglochin maritima 10 < 1 Plantago maritima 8 < 1 Carex extensa 15 < 1

.I Lf Description- Dense cover of Juncus maritimus tussocks over patchy coverof A rostis stolonifera with sparse salt tolerant species. 8m. Grading to heath with Ulex gallii, Molinia caerulea, Erica cinereaand Daboecia cantabrica.

18 R Loch Tanai u

G Site: Lough Tanai Transect code: B Location: Sheltered bay and isolated pool Sample point:1 Aquatic- 3m out C Sample area: 25m2 (5x5) Substrate: Silt (depth c.40cm

Depth: 25 cm Salinit : 30 parts per thousand NVC communit :----- 0 Height (cm) Cover Total Plant 100 Hiher Plant 30 0

Ruis s p. 30 30 Zostera marina 35 < 5 EJ

Algae 85 EJ Filamentous algae 80 Lam rothamnium papulosum 10 5 Ei

Description: Patchy cover of Ruis amongst extensive filamentous algae with patchy Zostera EJ and sparse Lam rothamnium. Some Ruis plants in flower. 0

0 Site: Lough Tanai Transect code: B Location: Sheltered bay and isolated pool Sample point: 2 Marginal Sample area: 16m2 (4x4) Substrate: Peat 0 Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover LJ Total Plant 100

Juncus maritimus 70 75 El Agrostis stolonifera 15 30 Aster tripolium 25 5 0 Glaux maritima 10 < 1 Triglochin maritima 15 < 1 M Plantago maritima 10 < 1 u Cochlearia anglica 6 < 1 Carex extensa 15 < 1 G n Description: Fairly dense cover of Juncus maritimustussocks over salt tolerant vegetation LJ dominated by patchy Agrostis stolonifera with associatedspecies sparse. 18m.

D 19 J

Loch Tanai

Site: Lough Tanai Transect code: B Location: Sheltered bay and isolated pool Sample point: 3 Marginal - Pool Sample area: 40m2 10x4 - whole stand) Substrate: Silt (depth c.50cm 7 Depth: 15 cm Salinit : 21 parts per thousand J NVC communit :----- Height (cm) Cover Total Plant 20 Hi her Plant 10

7 Ru is s p. 15 10 U Algae 10

Filamentous algae 10 Lam rothamnium papulosum 10 < 1

Description: Patchy cover of low growing Ruis with open filamentous algae cover and very J sparse Lam rothamnium. Both flowering and fiuitin Ruis present. Shallow isolated pool. 80% of substrate is unvegetated silt. Backing Juncus maritimus dominated community as sample point 2. 10m. Grading to Sphagnum s pp. - Molinia caerulea - Callunavulgaris bog vegetation.

Site: Lough Tanai Transect code: C Location: Freshwater inflow Sample point:1 Aquatic - 3m out Sample area: 16m2 4x4 Substrate: Silt ( depth c.30cm

Depth: 10 cm Salinit : 5 parts per thousand NVC communit :----- Height (cm) Cover LJ. Total Plant 100 r, Higher Plant 10

Ru is s p. 6 10

Algae 100

r-"r Filamentous algae 100

L Description: Patches of Ruis growing through filamentous alg ae in shallow water. Ruis low growing, both flowering and fruiting plants present.

L-w

20 u n Loch Tanai

M Site: Lough Tanai Transect code: C u Location: Freshwater inflow Sample-point: 2 Marginal Sample area: 8m2 Substrate: Peat 0 Depth: ----- Salinit : ----- NVC communit :Undetermined Height (cm) Cover tJ Total Plant 90

Puccinellia maritima 8 90 rJ Trilochin maritima 10 5 Glaux maritima 6 < 1 0 S erlaria marina 5 < 1 Aster tripolium 15 < 1 Plantago maritima 8 < 1 0 Limonium humile 20 < 1

LJ Description: Dense cover of Puccinellia dominantover sparse species-p oor salt tolerant associates. This community occurs here as patches (averagearea c.8m2 interlaced with unvegetated silt. 0

G

Site: Lough Tanai Transect code: C LJ Location: Freshwater inflow Sample point: 3 Marginal Sample area: 16m2 (4x4) Substrate: Peat

Depth: ----- Salinit : ----- 0 NVC communit :Undetermined Height (cm) Cover Total Plant 100 IJ

Juncus maritinus 80 90 IJ Agrostis stolonifera 15 20 Triglochin maritima 10 5 Glaux maritima 6 < 1 0 Aster tripolium 20 < 1 Cochlearia anglica 6 < 1 Plantago maritima 8 < 1 Limonium humile 20 < 1 0 Description- Dense cover of Juncus maritimus tussocks withsparse species-p oor understorey dominated by patchy Agrostis stolonifera. 20m. 0 Backing Ulex gallii- Calluna vulgaris - Erica cinerea dominated heath. n

21 J

Loch Tanai

rI U 14.3.4 Evaluation

J `Valuable' 7 This site shows a high degree of spatial salinity variation(5-32 parts per thousand at LJ time of survey), with low salinities around the major freshwaterinflow and high salinities around the outlet channel and elsewhere. Speciescomposition seems to suggest that the freshwater influence is localised. J Fucoid algae are abundant and well distributed around theshore. Phyllophora pseudo ceranoides also occurs here. Ruppia and Zostera marinaare abundant around much of the site in dense, often mixed stands. It is considerednotable that both Ruppia maritima and R.cirrhosa occur here.

This is the second new Irish station for therare charophyte Lamprothamnium papulosum (the other being Lettermullen Pool), previouslyknown from only three sites. Lamprothamnium ismore or less frequent around most of the shore and abundant in places, often growingamongst Ruppia beds. Its presence here is reason enough in itself to regard this siteas valuable. rl

u- A distinct zonation of algal and higher plantspecies occurs along the rockier shores with dense Ruppia and Zostera beds, frequently withLamprothamnium, lying beyond a narrow belt of fucoids.

Marginal vegetation is restricted due to the rocky,steep-sided nature of much of the site. No emergent speciesoccur here. The dominant marginal community is species- poor salt tolerant vegetation dominated by Juncus maritimus.

Loch Tanai is a good representative ofa highly saline lagoon with a permanent connection to the sea. Species composition andshore zonation are interesting, frequency and abundance of most speciesare high and a rare charophyte has been J found here in abundance.

A full aquatic survey is recommended.

J

22 :J

Loch Tanai

14.4 ECOTONAL COLEOPTERA J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

14.4.1 Site Description

Bayhead brackish lagoon with c.7m wide inlet without surface barrier,surrounded by heath (incl. Pteridium) and blanket bog on glacial deposits with rockoutcrops and boulders. Summer J spring/neap cycle tidal response of >0.2m. Lake shore with exposedgranite rock, boulders, cobbles and pebbles, peat cliffs and sheltered lake bay peat-flatsdominated by Juncus maritimus and grass/sedge/Juncus sp. swards (Plate 1). These swards muchlarger than at the nearby L. Carafinla, but several hectares of Juncus maritimus vegetation(unvisited) appears to occur north of L. Carafinla, and east of L. Atawny.

Subsites (see Fig 14.4.1)

1. Sedge/grass/Juncus V. (North) (L 950306) Plate 2 c. 0.1 ha stand of Juncus maritimus with Glaux maritima,Triglochin maritima, Plantago maritima, Eleocharis ?-uniglumis, grading into grass/sedge/Juncus sp. sward on verygently sloping peat shore, in relatively sheltered northern bay of lake.Bare peat exposed (July) downshore of Juncus maritimus stands.

2. Juncus maritmus / grass (South) (L 952304) Juncus maritimus grading into grass-dominated sward on southern sheltered bayof lake, although with more irregular and in places more sloping topography.

2. Cobble shore (L 952305) Shore with granite cobbles and large pebbles on coarse sand/peat,covered during flooding. Also Juncus litter and fibrous algal mats in places.

14.4.2 Methods 7 LJ- Site Rating using Indicator Species

i Species rarity or community typicalityare the most frequently used criteria for rating n sites for their biological conservation value. The approach in thisColeoptera survey is u. to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

23

2 U

0

tJ

LJ

N G

t o

I o

EJ

0

0

0

0

C

tJ

c

C

Fig. 14.4.1 Map of sampling sites (Carabidae and Staphylinidae)at Lough Tanai, Co. Galway. 0

I- Pitfall traps, S-vac, Ground search 2 - Cobble search 3 - Pitfall traps

tJ

0

0 Loch Tanai

Indeed, in one case, a rare species has been excludedas an indicator because it lacks a J specific requirement for habitats created in the lagoon sites.

Therefore, species were selectedas indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literatureas being local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking intoaccount the number of individuals of the species present (singletonsare often vagrant); (2) The habitat requirements of the non-indicator species, if they indicatedan anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance). 7 J Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for u' instance). Sites were not rated ofaverage value if there were less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are basedon recorded data using standardised sampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, anddo not represent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera,etc.) or herbivorous 7 assemblages (e.g. Lepidoptera). Different indicator species Lj are likely to occur in spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites. u7 Sampling Strategy At each site representative marginalareas were sampled, including vegetation dominated by Scirpus maritimus, Juncus maritimus, Juncus gerardiand grasses, as well as bare or poorly- vegetated areas of sand, silt or peat. Particular emphasiswas given to habitat associated with the sedimentary barrier andareas of highest salinity, since much of the habitat associatedwith freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods usedare listed in Table 14.4. 1. For each site, aStihl® BR 400 suction apparatus, mounted on the operator's back,was used. This machine (referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter

24 U

Loch Tanai 0

(0.0026 m2 surface area). Six subsamples (transects)of 100 x 1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held 0 pipe was shaken when theapex of the pipe was in the vegetation, a largerarea (c. 2 m2) was n effectively sampled. Sets of six pitfalltraps with undiluted ethylene glycol (commercial anti- U freeze) preservative were also dug into the soilat each site. Because many of the species expected to occur in such a habitatare adapted to climbing during flooding, these trapswere fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were 0 used for the traps themselves.

u

TABLE 14.4.1. Details of sampling methods. D

EJ Method Details No. replicates Sampling period, etc. per unit sample 0 Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and 0 plastic funnels; collars used where cattle/horses occur Cobble samples Cobbles turned 0.5- 2 m 30 0 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; 0 agitated soil floated in water Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during 0 warm weather without rain rJ

Habitat features associated with the sedimentarybarrier, such as shingle cobbleson finer substrate, bare or poorly vegetated sand, and peat cliffs, were also sampled if they occurred to tJ a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather,or a fixed number of cobbles turned (n = 30)or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. 0 Sampling was carried out during latesummer and early autumn (late July to early October), with some sites visited in June. Thiswas unavoidable, and due to time constraints associated with the survey, but it is assumed that thespecies occurring during this period are tJ representative of the sites,even if spring species may be absent.

Variety of sampling techniques 0 Several techniques will always givea more robust picture of the fauna of a site, because any weather-or site-affected bias in one technique will be compensated by 0 other sampling methods. Some sites didnot possess suitable habitat (peat cliffs, bare sand, cobbles on sediment, etc.) for flotation,ground search or cobble search. This is 0 25 n Loch Tanai

regarded as an absence of habitat, rather than an unavailable sampling opportunity. J That some sites, therefore, had more sampling effort using these additional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of >1m) where flooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in L j' the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv. : Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Jr. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : Sedge/grass/Juncus sp. (North) area- S-vac suction sampler (16 viii 1996), c. 2m2; Sedge/grass/Juncus sp. (North) area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (6 vi- 16 viii 1996); Juncus maritmus / grass (South) area- 6 pitfall traps (16 viii - 28 ix 1996);

r-P Cobble shore - cobbles search (n = 80 cobbles) (6vi 1996).

Species were selected as indicators of conservation value if: (1)they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they

26 n Loch Tanai u

are reported in the literature as being local or rare,from which it is assumed that theyare less likely to survive in historically degradedecosystems. EJ

14.4.3 Results D

Three species of carabid and seventeen species of staphylinidwere recorded, two species of 0 which are regarded as indicator species (Table 14.4.2).No carabids or staphylinidswere recorded under cobbles. 0 Philonthusfumarius appears to be local in Ireland (Johnsonand Halbert 1902, Lott and Bilton 1991) and is recorded as very local in Great Britain(Hyman and Parsons 1994). It is notrare in Central Europe, but ratherrare elsewhere (Horion 1965). The species is restricted to 0 marshes including muddy and marshy freshwater shores(Horion 1965, Koch 1989), and especially on coastal marshes (Hyman and Parsons 1994). 0

0 TABLE 14.4.2. Carabidae and Staphylinidae (Coleoptera) recorded fromLough Tanai. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0

Species No. individuals G

Carabidae C

Agonum gracile (Gyll.) 1

Elaphrus cupreus Duft. 1 Pterostichus niger (Schall.) 3 0 Staphylinidae 0 Amischa analis (Grav.) 1

Atheta volans (Scriba) 1 Drusilla canaliculata (F.) 3 Erichsonius cinerascens (Grav.) 2 0 Euaesthetus ruficapillus Bois. Lac.7

Lathrobium quadratum (Payk.) 1 Lathrobium terminatum Grav. 3 C Lesteva sicula Er. I Paederus fuscipes Curt. 2 * Philonthus fumarius (Grav.) 1 Indicator species 0 Philonthus nigrita (Grav.) 1

Stenus brunnipes Steph. 1

Stenus canaliculatus Gyll. I Stenusfuscipes Grav. 5 EJ Stenus incrassatus Er. 76 Stenus nitidiusculus Steph. 2 * Stenus opticus Grav. 4 Indicator species 0

0 27 Loch Tanai

There is a single Irish record (1929) of Stenus opticusfrom Ballynahinch Lake (Co. Galway) (Anderson 1984), and the species is listed by Hyman andParsons (1994) as very local in Great Britain. It is not particularly rare in northernor north-eastern Europe, but local in western Europe (Horion 1963). The species is restrictedto marshes, alder carr and bogs, occurring in Sphagnum and Carex (Horion 1963, Koch 1989).

The staphylinid assemblage in the sedge/grass/Juncussp. area was characterised by most species being associated with bogsor marshy shores (Table 14.4.3).

TABLE 14.4.3. Staphylinid assemblage from sedge/grass/Juncussp. area, Lough Tanai (S-vac suction sample and pitfall traps combined). Abund. Cat. refersto category of relative abundance (no. individuals: 1, 2-/0,/1+).

Abund. Cat. Species No. Main biotope

Dominant Stenus incrassatus 76 Eurytopic, wet soils incl. bogs

Intermediate Drusilla canaliculata 2 Heaths, bogs & grassland Erichsonius cinerascens 2 Eurytopic, wet soils incl. bogs Euaesthetus ruficapillus 7 Marshes, also bogs Lathrobium terminatum 2 Marshes, also bogs Stenusfuscipes 5 Mesotrophic/eutrophic marshes, riparian Stenus nitidiusculus 2 Eurytopic, incl. blanket bogs Stenus opticus 4 Flooded soils, also blanket bogs Present Amischa analis 1 Eurytopic, incl. disturbed agricultural land J Atheta volans 1 Marshy shores incl. upper sea shores Lathrobium fennicum 1 Marshes, also bogs Lathrobium quadratum 1 Marshes, also bogs Lesteva sicula J 1 Marshes, also bogs Philonthus fumarius 1 Marshes and marshy shores Philonthus nigrita 1 Bogs Stenus brunnipes 1 Woods & grassland incl. freshwater shores Stenus canaliculatus 1 Eurytopic, incl. muddy sea shores and bogs

14.4.4 Evaluation

Of average but potentially exceptional conservationvalue for terrestrial ecotonal community. This requires further investigationto confirm or refute this potential rating. (Rating categories : None, low,average, exceptional]

Scientific Argument for Rating 7 Ll The presence of two indicator species (Table 14.4.2), plusa majority of staphylinid species associated with bogs and wetlands (Table 14.4.3), indicatesecologically well-developed

28 LJ

Loch Tanai 0

habitat. The diversity of wetlandspecies and large numbers of Stenus incrassatus,a eurytopic but local (Anderson 1984) species,indicate that this assemblage isat least seasonally LJ associated with the habitat sampled,and not occasionally vagrant from thesurrounding bog. Many of these species have been recordedfrom wet Sphagnum in bogs, andmay benefit from the high water table maintainedat the lagoon shore during the dryseason (summer). 0

Lough Tanai (and by extrapolation similar n bayhead Juncus maritimus habitat inthe vicinity) u may be potentially exceptional for the followingreasons : (1) The pitfall traps did notoperate very efficiently on peat at this site, whichmay be a result of their placement toonear the shore (i.e. indicator species occur further up the shore), so further indicator speciesmay have been 0 missed; (2) The two indicator speciesoccurred in a well-defined peat ecotonalhabitat; (3) The hypothesis is proposed that the bayheadlagoon margin peat-flat habitat surroundedby blanket bog may maintain a dry-season water table, while a similar freshwater lake wouldprovide poor 0 habitat due to drying out,or a barrier lagoon would be prone to flooding ifa barrier was present blocking outflow; (4) This peat/lagoonecotonal habitat may be unique to Atlantic coasts. However, this potential rating requiresto be confirmed or refuted by furthermore 0 detailed investigation.

0 15.4.5 References

Anderson, R. (1984) Staphylinidae(Coleoptera) in Ireland- 3: Steninae. Jr. Nat. J. 21: 242- 0 251. Horion, A. (1963) Faunistik der MitteleuropaischenKafer. IX. Staphylinidae: Micropeplinae bis Euaesthetinae. Feyel, Oberlingen-Bodensee. 0 Horion, A. (1965)FaunistikderMitteleuropaischenKafer.X. Staphylinidae: Paederinae his Staphylininae. Feyel, Oberlingen-Bodensee. Hyman, P. S. and Parsons, M. S. (1994)A review of the scarce and theatened Coleopteraof 0 Great Britain. Part 2. UK NatureConservation Series No. 12, Joint Committeefor Nature Conservation, Peterborough. 0 Johnson. W.F. and Halbert, J.N. (1902)A list of the beetles of Ireland. Proc. R.Jr. Acad. (3) 6: 535-827. Koch, K. (1989) Die Kafer Mitteleuropas. Okologie. 1. Goecke & Evers,Krefeld. E Lohse, G.A. and Lucht, W.H. (1989)Die Kafer Mitteleuropas. 12. 1. Supplementbandmit Katalogteil. Goecke & Evers, Krefeld. Lott, D.A. and Bilton, D.T. (1991) Records of Coleoptera from Irish wetlandsites in 1989. 0 Bull. Jr. biogeog. Soc. 14: 60-72. Lucht, W.H. (1987) Die Kafer Mitteleuropas.Katalog. Goecke & Evers, Krefeld. 0

0

C

0 29 Lough Tanai 5

Plate 1 Lough Tanai, Co. Galway

J

:f

Plate 2 Juncus and grass on peat shore at Lough Tanai, Co.Galway

L Loch Tanai J

14.5 SUMMARY AND EVALUATION

Loch Tanai is a medium-sized (12 ha) natural saline lakein peat with a long, possibly artificial, tidal inlet through peatland. The lake is not part of a proposed NHA butlies close to the proposed Kinvarra saltmarsh NHA (Site Code No. 2075) The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system J which varied for each criterion.

Geomorphology Moderate/High Aquatic Fauna High/Exceptional rj Vegetation Exceptional LJ Ecotonal Coleoptera Average/Potentionally Exceptional

Geomorphology.

Loch Tanai is an unusual type of natural saline lakein peat with a long, possibly artificial, tidal inlet. It may have originated in oldpeat cuttings. It is one of several similar lakes in the peatland area south of Camus Bayall of which have long inlets and rl may have similar origins. Although not a lagoon in thestrict sense because the barrier J is neither sedimentary or of rock, it presentsmany of the characteristics of lagoons e.g. it is shallow and brackish. It could be describedas a lagoon with a peat barrier.

J As an unusual type if saline lake in good condition,the lake is rated as of high conservation value.

Aquatic Fauna

Among 36 taxa recorded, six speciesare lagoonal specialists. In spite of the soft substrate, much of whichwas unconsolidated peat, burrowing forms were relatively well represented throughout the lake andwere not more abundant or diverse at stations withmore sand or silt. The most abundant species at all stations was Praunus flexuosus. Cerastoderma glaucumwas represented by both adults and juveniles. U7 Faunistically, the lake is a good example ofa lagoon with salinity in the middle to upper range. A wide range of ecological types of invertebratewas represented and there were some unusual species present,e.g. Akera bullata and Syngnathus typhle, but no rare species were recorded.

30 u

Loch Tanai Ei n u Loch Tanai, and the other similar lakes in thearea, appear to be unknown to marine biologists and their communities have not, therefore, been investigated.The habitat is unusual for brackish species. rJ

Based on the high faunal richness and the number oflagoonal specialists, the lake is rated hi h/exceptionl. E Vegetation E Species distribution reflected a high degree of spatial variation insalinity. Fucoid algae were abundant and well distributed around the shore. Phyllophora pseudo- ceranoides also occured here. Ruppia and Zosteramarina were abundant around 0 much of the site in dense, often mixed stands.It is considered notable that both Ruppia maritima and R. cirrhosaoccur here. 0 This is the second new Irish station for therare charophyte Lamprothamnium papulosum (the other being Lettermullen Pool), previously knownfrom only three sites.It was more or less frequent around most of theshore and abundant in places, a often growing amongst Ruppia beds. Itspresence here is reason enough in itself to regard this site as valuable. 0 A distinct zonation of algal and higher plant species occuredalong the rockier shores with dense Ruppia and Zostera beds, frequently withLamprothamnium, lying beyond a narrow belt of fucoids. Ll

Marginal vegetation was restricted due to the rocky, steep-sidednature of much of the 0 site. No emergent species occurred here. The dominantmarginal community is species-poor salt tolerant vegetation dominated byJuncus maritimus. LI Loch Tanai is a good representative ofa highly saline lagoon with a permanent connection to the sea. Species composition and shore zonationare interesting, frequency and abundance of most specieswere high and Lamprothamnium was Ll abundant. For these reasons, the lake is ratedas of exceptional conservation value

A full aquatic survey is recommended. Ll

Ecotonal Coleoptera 0 Three species of carabid and seventeen species of staphylinidwere recorded, two species of which are regarded as indicator species. No carabidsor staphylinids were recorded under cobbles. 0

Philonthus fumarius appears to be local in Ireland and isrecorded as very local in Great Ei Britain. It is not rare in Central Europe, but ratherrare elsewhere. The species is restricted to marshes including muddy and marshy freshwater shores and especiallyon coastal marshes. 0

0

31 Loch Tanai

There is a single Irish record (1929) of Stenus opticusfrom Ballynahinch Lake (Co. Galway), and the species is listed by as very local inGreat Britain. It is not particularly rare in northern

or north-eastern Europe, but local in western Europe.The species is restricted to marshes, 7 alder carr and bogs, occurring in Sphagnum and Carex. LJ The presence of two indicator species, plus a majority ofstaphylinid species associated with J bogs and wetlands, indicates ecologically well-developed habitat. The rating of average but potentially exceptional conservation value requiresfurther investigation.

Summary

Loch Tanai is an unusual type of natural saline lakein peat which presents many of the 7 characteristics of lagoons. It could be described as a lagoonwith a peat barrier. It is l_J valued as moderate/high for its geomorphology because the type israre, and possibly unique, in the European context.

U A wide range of ecological types of aquatic fauna arerepresented, and a relatively high proportion of lagoonal specialists. The habitat is unusual for brackishspecies (see also Cloonconeen Pool).

Species composition and shore zonation of the vegetation are interesting,frequency and abundance of most species are high and Lamprothamnium wasabundant.

The presence of two indicator species of ecotonal Coleoptera, plusa majority of staphylinid species associated with bogs and wetlands, indicates ecologically well-developed habitats. This peat/lagoon ecotonal habitat may be unique to Atlantic coasts.However, the potential rating requires to be confirmed or refuted by furthermore detailed J investigation 7 Overall, the site is rated as of high and possiblyexceptional conservation value as an J unusual type of saline lake with rich and interesting faunaand vegetation. Its designation as a proposed SAC is recommended and studyof some similar lakes in I LJ the area is worth consideration.

u

32 '-1

LJ COASTAL LAGOONS IN THE REPUBLIC OF IRELAND J (VOLUME 111)

15. LOUGH ACONEERA

J Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February1997

,II

r,

:J

7I LJ Prepared for the National Parks and Wildlife Service

(BioMar/Life) J

15. LOUGH ACONEERA

CONTENTS

15.1 Study Area

15.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

15.2.1 Methods 15.2.2 Results 15.2.3 Discussion 15.2.4 Threats 15.2.5 Evaluation 15.2.6 References

15.3 Vegetation Survey (Pat Hatch)

15.3.1 Site Description 15.3.2 Methods 15.3.3 Results Shore based survey J Transect tables 15.3.4 Evaluation 7 LJ 15.4 Ecotonal Coleoptera (Jervis Good)

15.4.1 Site description 15.4.2 Methods 15.4.3 Results 15.4.4 Evaluation 15.4.5 References

15.5 Summary and Evaluation

J

J

7

u Lough Aconeera

15. LOUGH ACONEERA, Co. Galway. u OS Grid Reference: L 875 369, 1:50,000 Sheet No. 44 7 Alternative names: Loch Conaortha, Loughoneera LJ

15.1 STUDY AREA

General features Lough Aconeera is situated on the northern shore of KilkieranBay, western Connemara, 6 km north of Kilkieran. The lake is relativelylarge and deep in places and u differs from many of the coastal lakes of Connemara inthat it lies at the base of a mountain range, Cnoc Mordain, which risesto 354 m within 1 km of the lake (Fig. 15.1.1). The lake has formed in whatappears to be a flooded block field at the baseof the mountain which may at one time have been blanketedin lowland peat. The bed of the lake is mostly composed of granite bedrock and detachedblocks and boulders, with patches of coarse sand and unconsolidatedpeat in the sheltered areas. An apparently permanent stream enters the lakeon the northwest shore which at times is r1 likely to be torrential. Numerous other smallerstreams are likely to appear during periods of heavy rainfall. An outletruns under the road from the lake through an area of peat and rock in the southeast of the lake.The lake is exposed to strong winds, intensified by the presence of the mountain, whichcan quickly produce waves on the J lake. Lough Aconeera is included asa good example of a type of lagoon, rare ina European J context, but characteristic of parts of the west coast ofIreland, especially in Connemara, which are permanent, brackish, with restrictedtidal influence due to the presence of a "barrier" of peat. These "peat" lagoons areof particular interest as very little appears to be known aboutany aspect of the functioning of brackish lakes situated in acid peat lands. n Very little is known about the lake. Itappears to have no protective status but does not u appear to be under any immediate threat. u Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompaniedby rain and strong winds. The mean daily air temperature is around 5.5 °C inJanuary and 14 °C in July. The growing season (the period ofmean daily air temperatures above 6 °C) is 8.5, andas snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1400mm, and the number of rain days (1 mm ormore) is approximately 200. Winds are mainly from the southwest.Mean annual hourly wind n speeds are between 5-6 m/s anda maximum wind speed of 50 m/s is estimated to

LJ occur once in 50 years. The daily duration of brightsunshine averages 3.5-4.0 hours. Mean relative humidity is around 85%as on all Irish coasts. 7 LJ

1 jn, of BonnowLorn l.,gn nA Broc" ro Aconeera Lough

Snjilr,lwurd Seaman lathers Ch An tOr aliiar I'dcanegos na', RosduAos I

Cn y n r J turn : `y lou Uo .., ` . 1 '`= Doire, forDerryrus - is 1 'r 'r ,ou / Carriekpby,, j ./ v' ' .-'..-_.._` Br__ of C]$e a '\i em Anal nah 'o U Ccl, .... ll lanfo I L I I ^. ` oc" 01# In drn11 no, RoS - a Glennal,n I url&u hPolnl R Lougtiacone f I Roc Whel Rou Rce H oc"' , Loch Conao J ,.:,` Bulanecnru Rock llaunnapa pots0110A p0)spd t { `, Rockwhile RI N I{Well and h v fe;+nnnn U ©(1 . 1 G CrA Llend QRock non. it;n, kbn ' _ .ll BnreaCAin - _ i -''L a5 _ _ A B 5 R oc 11 Cilll / nnLAd, na nnalrnn k K s li a -'-__ Illaune y aunmor i C0,11 S9 ye a ras AtJO!leAn`Iv1or R o. ua°n l V I . Rol _ kl aff.I - c f n n n n O{ D ' : Psik . l ` ` ` \ ell i C __- An Bni119 ch -An NBnaln. wOlln rnyadn JlnIshiravln "I",Roer

j ...JRoscom vonl I D Rosk eoa urlougnoeg -J 0 L_J 0 0 0 0 Roe Cam 1 ', . .. An Tuelacn 0 0 1 Id Rot i09e ' 0 Owem Rock 0 0 Beeg Ga,// v :nli ag ,, . Noltn I slan Roc4f /: r f ugAmpan Pt Q!n IOf{I Tnu l I 9idrl''/.__IeA Ill aunar ( o 0 n 'J ; N.df R°u Bean ar An t0deli;'-1 GBIDn i° elnq W n ` k' KifkiereaunoC#,onrfal nle CnfelemOwe{ / Rinnelf{ Rocs 4 , ,,( t ( lelgnon Iso ' / X. slano3 nnelly ;, Congnnd Row Clui ' \) I wearnot La,dhean r 0 0 ' 0 0 . '. ; _ ' _ 0 0 , ' lam' til 0 n Lough Aconecra u

r'1 Marine processes in the area are dominated by long periodAtlantic swell waves with u median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8m (Carter 1992). Maximum wave heights (averaging once in 50 years) are 30-35 m(Couper 1983). Tides are semi- diurnal and the tidal range (MHWS-MLWS) at Kilkieran is 4.2m (Admiralty Tide Tables). Sea temperatures are lowest in February ( around 7°C)and highest in August (14.5 °C). Landscape and Geology The Connemara region of Galway is a glaciated plain of rolling lowland with granite outcrops and Atlantictype blanket bog. The granite bedrock is impervious and drainage density is high. Soils otherthan peat are shallow podzols with very limited land-use capability (R.I.A. 1979). Thearea was described by Haughton (1957) as a "wilderness of bare rock, glacial erratics,water and peat". J Lough Aconeera differs from many of the coastal lakes ofConnemara in that it lies at the base of a high mountain range and lies inwhat appears to be a flooded block field at the base of the mountain which may at onetime have been blanketed in lowland peat.

Land surrounding the lough consists of small irregular fields ofsemi-improved pasture, 7 bare rock, small peatbogs and wet heathland. LJ Lake Topography The lagoon is approximately 750m from west to east, 400 m n from north to south and covers about 28 ha. Waterdepth is 1- 1.5 m over most of the u lake but greater than 5 m in one centralarea at the eastern end. The bed of the lakeis mostly composed of granite bedrock and detached blocks and boulders,with patches of coarse sand or unconsolidated peat and silts in the J sheltered areas. It is possible that peat wasonce cut in the area occupied by the lake. Thechannel connecting the lake to the sea appears to have beencut deliberately but it is not known J at what date. It is possible that it was cutwhen the road and bridge were constructed to avoid flooding of the road. According to local information,seawater used to enter the lake during storms in an area further 7 to the southwest until the level of the road at .LI that point was raised. Hydrology Fresh water enters the lake througha stream in the northwest, and 7 presumably through several others during periods of highrainfall. Undoubtedly LJ freshwater also enters through the slow release of groundwaterfrom the saturated peat higher in the valley and also in direct rainfall. Seawaterappears to enter on all tides, 7 through the channel which leads under the bridge. It isnot known if seawater can still L] enter by any other means. There is an apparent daily tidal fluctuation inwater level of c. 10 cm during neap tides and a difference of c.30cms between the mean water level at spring tides andthat during neaps. A seasonal pattern is likely, wherebywater levels rise in the winter with the increased rainfall and storm frequency, and graduallydecline in the summer. The peaty soils of the surrounding land would, however, through absorptionand slow release of water, affect the delivery time of both surface-and ground-water flows to the lake.

Salinity and water quality Despite the fact that seawater appears to enteron every tide the lake is also likely to receive large volumesof freshwater runoff from the mountain and surrounding land. Salinity levelsare likely to be mesohaline through most of the year, with a rise during the summerand decline in the winter. The peaty 7 LJ

2 Lough Aconeera 0 soils of the surrounding land would, however, affect the flowsof both surface- and ground-water to the lake. The prolonged flow of freshwater tothe pool during the 0 "dry" months may result in lower salinities than might beexpected. On the other hand, winter storms may result in a higher volume of seawaterentering the lake and raising salinity levels at a time when they might be expectedto fall. 0 The depth of the lake is likely to cause stratificationalthough exposure to strong winds would ensure regular mixing. 0 The surrounding land is relatively natural and even grazing landis likely to receive only limited fertilizer applications. Water quality appears to be high althoughquite a deep layer of organic silt has accumulated in some areas ofthe lake and there is a dense 0 growth of pond weed and filamentous algae in the westwhere the freshwater stream enters. The regular flushing of the lake would restrict anyproblems caused by eutrophication. 0

E

0

0

0

0

0

0

0

0

G

G

0

0 3 n 7 Lough Aconeera u 15.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, UniversityCollege Dublin 15.2.1 Methods

Environmental variables Water depths were measured usinga plumbline from an inflatable dinghy. LI

The position of each samplearea was determined using a GPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturersof the GPS state that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but alsoto record changes in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No.1270, Chemlab, U.K., 1 %o 7I LJ precision). A photographic recordwas made of the site and local information sought concerning background and recent history. J Faunal Sampling. Faunal samples were collected bya combination of sweepnetting (mesh size 0.5 mm), sieving of sediment (1 mm mesh) and close inspectionof stones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containinga chemical light which glowed for 8 hours. The boxeswere constructed in the Zoology Dept. at U.C.D. according to the model described by Holmes & O'Connor(1988). Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification.

Fyke nets were used at stations A and E inorder to gain additional information n concerning larger fish species which wouldnot be recorded using the above methods. u Standard procedure was that followed by Moriarty (1975)and Poole (1994). The nets used are referred to as summer Tykenets and consist of two traps, facing each other, rl joined by a leader net, mesh size 16mm. The trap at each end consists of two L. chambers and a cod end with knotto knot mesh sizes of 16, 12 and 10 mm., respectively. Nets were generally placedat right angles to freshwater inflows or tidal inlets in order to trap fish swimming from eitherdirection. All fish were recorded and J returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in thesurvey are affected by many environmental and biotic n variables including season, state of the tide, weather,nature of the habitat and life u cycles of the species involved. It is therefore difficultto make quantitative comparisons between lagoons, or even between stations withinthe same lagoon, as they are 7 LJ 4 Lough Aconecra 0 sampled at different times and often witha different sampling method. The results of the light-traps come closest to quantitative sampling, buteven these are affected by 0 inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories ofpresent, common and abundant are purely subjective, and absolute numbers vary between taxa. 0 Several faunal groups were sorted and distributed to specialists (e.g.Coleoptera ). Standard keys were used to identify remaining specimens, butmany of these were larval or juvenile stages and difficult to identify with certainty.Some groups require 0 adult males for identification and these were often not availabledue to low population density and the limited number of individuals collected in thetime available (e.g. Jaera, hydrobiids). 0 All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same 0 species.

15.2.2 Results 0

Lough Aconeera was sampled on the 13.vi.96 during the firstpart of the survey, and G from 5-6.ix.96 during the more intensivesurvey. n Five sampling stations were selected in the lake to reflectthe influences of substrate, u and freshwater/seawater inflows. Fig. 15.2.1 shows the position of thesesampling stations in the lagoon. Further detailsare given in the Results section. 0 Environmental Variables Positions of the sampling stations are shown in Fig. 15.2.2. 0 Station A (OS 8787 3683) was located at the easternend of the lake nearest to the road and the outlet channel whichruns under the bridge and is the most tidal areaof the lake (Plate 15.2.1). Water depth varied from 0- 60 cm, substrate was smooth slabs 0 of granite bedrock, stones of various sizes and small pocketsof coarse sand and gravel. Salinity was surprisingly low and measured 13 %oat the outflow during low tide. 0

Station B (OS 8716 3683) was located in the southwestcorner. Water depth was 0 - 60 cm, substrate consisted of small cobbles andcoarse granite sand and salinity 0 measured 13 %o. Station C (OS 8718 3700) was located in the northwestcorner, near a bed of 0 Phragmites . Water depth was 0 -30 cm, substrate wascoarse granite sand and salinity measured 10 %o. Station D (OS 8728 3692 ?) was locatedon the northern shore of the lake where a 0 stream enters (Plate 15.2.3). Depth varied from 0 cm- 1.2 m, substrate was rock with pockets of soft organic mud and salinity measured 12 %o. C Station E (OS 8769 3714) was locatedon the northeast shore among Phragmite.s (Plate 15.2.2). Water depth varied from 0- 1.2 m., substrate consisted of coarse granite sand, organic silt and fibrous roots, and salinity measured12 %o. 0

0 5 n __.] L__] C___J U L a L_i L_I L__] Li L1 L-1 L---j U L_I LI L__i LI L__j L_i L_J L-:

870 Fig 15.2.1 Location Map of Sampling Stations in Lough Aconeera, Co. 880 Galway. Table 15.2.1Fauna Recorded in Lough Aconeera. June and September, 1996. EJ () = records from June.

- -- Sampling Stations (L.T. = light-trap) AL.T. B C L T D L.T.E EL.T.E 0 Porifera Cnidaria ------Turbellaria (+) + + 0 Nemertea Annelida Arenicola marina + + Crustacea EJ Ostracoda Copepoda Cirripedia 0 Mysidacea Neomysis integer a 250 + a 200 c 200 a 800 IsopodaIdotea sp. + 1 a Jaera nordmanni + + + Lekanesphaera hookeri a 150 + e 100 a 250 c 50 Amphipoda Corophium volutator + G Gammarus duebeni + + + + + + + G.zaddachi + + + + + Tanaidacea 0 Decapoda Carcinus maenas + F, 1 F, 2

Palaemonetes varians (+) + 1 Arachnids C Insecta Thysanura Ephemeroptera (+) 0 Odonata Ischnura elegans + + + 4 Plecoptera Trichoptera(cases) + G Hemiptera Coleoptera Gyrinus caspius (+) G Diptera Chironomidae + + + + Mollusca

Prosobranchia Potamopyrgus antipodarum + + + i + + G Opisthobranchia _ Pulmonata

Bivalvia Cerastoderma glaucum ' a E Mya arenaria + + + i Mytilus edulis +

Bryozoa Conopeurn seurati + + ! + 0 Echinodermata Tunicata _

Teleostei jAnguilla anguilla_ F, 2 1 F, 7 0

jGasterosteus aculeatus j c j 1 c c j 3 c 3 c 26

_ Platichthys flesus F, 5 j - _ 0 !Po pistils micros c 1 c c 4 C 6Fc 7

0

0 + = present; o = occasional; c = common; a= abundant; F = fyke net Lough Aconeera

Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 15.2.1. Among 22 taxa listed, 20are identified to species. The list (excluding 7 marginal species) comprises 1 marine species, 3 poly-mesohaline,12 euryhaline, and 3 U oligo-mesohaline; no limnic specieswas recorded (Table 15.2.2). Four species are listed as a lagoonal specialists in Britain (Davidsonet al. 1991). u Table 15.2.2 Ecological categories of the recordedtaxa in Lough Aconeera (excluding marginal species). L = lagoonal specialist accordingto Davidson et al. (1991).

J Marine Mytilus edulis

Poly-mesohaline Arenicola marina Cerastoderma glaucum L Mya arenaria Euryhaline Neomysis integer Lekanesphaera hookeri L Jaera nordmanni rl Gammarus zaddachi J Gammarus duebeni Palaemonetes varians L Carcinus maenas Conopeum seurati L J Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps Platichthysflesus

Oligo-mesohaline Ischnura elegans Potamopyrgus antipodarum Gyrinus caspius

Limnic None

Many species appeared to be patchily distributed butthere were no conspicuous differences between stations in spite of the differentsubstrates. Arenicola marina was present only in sandy areas, but the burrowing amphipod Corophiumvohitator was only found at A where the substratewas mainly rock. Neomysis integer, Lekanesphaera hookeri, Gasterosteus aculeatusand Pomatoschistus microps were abundant at all stations. Cerastoderma glaucumwas confined to A nearest to the J outlet. J 15.2.3 Discussion The species assemblage typifiesa lagoon fed principally by non-point sources of u freshwater, with small incursions ofseawater by way of an open inlet. The species composition is characteristic of middleto low salinity waters not subject to frequent colonisation from the sea. The salinitywas similar on both sampling occasions in 1996 and 7%o was measured in March 1994. The absenceof limnic species indicates that there is always a significant marine influence.

6 Lough Aconeera 0

Cerastoderma glaucum was present here in abundance at much lowersalinity than at other sites where it occurred. This was the only siteat which live Mya arenaria, a 0 common species of estuaries, were present. None of the recordedspecies can be described as rare in Ireland 0 15.2.4 Threats 0 No immediate threats to the lake were apparent.

15.2.5 Evaluation 0

Lough Aconeera is a natural saline lake witha natural, partly tidal, inlet. 0 It is a good example of a large lake ofa type, probably also frequent in Scotland, which can be classified as a saline peat lake. Itdiffers from others in the region in being 0 somewhat deeper and having a substratum composed ofa larger proportion of bedrock and large boulders. As little appears to be known aboutthe functioning of peat lakes, this one may be worthy of further study but itis a different type from the more 0 shallow, dominantly peat lagoons.. The fauna was typical of a lagoon in the middleto low salinity range, and included four lagoonal specialists but nothing of special interest. Norare species has been recorded.. 0 The lake lies close to the edge of a proposedNHA (Site Code 2008) and could be included in that area. Its designation asa proposed SAC is recommended. 0

15.2.6 References and Additional Sources of Information 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department 0 Barnes, R.S.K. 1989 Coastal lagoons of Britain:an overview and conservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. C Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. 0 Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Haughton, J.P.1957. Physiography and Climate. In: Meenan, J. & D.A. Webb.(eds.) a A View of Ireland. Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine 0 crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. 0 Hutchinson, C.1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. 0

rJ 7 n i Lough Aconeera n Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. u 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand 7 movement. Ph.D. Thesis, Dublin University. LJ Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the 7 Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 LJ pp- Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. J

7 LJ

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8 Lough Aconecra J 15.3 VEGETATION SURVEY

J Pat Hatch, Sherkin Island Co. Cork u Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and considerationfor legal protection.

15.3.1 Site Description(Fig. 15.3.1)

Lough Aconeera lies between Cnoc Mordain andthe sea. The site is bordered by heath, bog and associated grassland. Rockoutcrops and dry stone walls are frequent across the surrounding landscape. Thearea is subject to grazing.

J There is an area of small hand-cut hayfields betweenthe south eastern shore and the public road.

J Shores are predominantly rocky, of both steeply slopingexposed bedrock and boulders, with low peat cliffs in places. The 7 only exceptions are the small swampy areas of sheltered bayheads and the south eastern shore, wherePhragmites and LJ Schoenoplectus swamp ismore extensive. This is the point of entry for themajor freshwater inflow. Several other small inflowstreams join the lough along its northern shore. n The outlet channel exits at the southeastern corner. J

7 LJ 15.3.2 Methods

Two survey methods were employed in thecourse of fieldwork: 1. Transects 2. Shore-based survey r1 J 1. Transects

The locality of these is shown in Fig. 15.3.2.

Each transect ran from the aquatic 7 zone, through adjacent marginal areas, to the adjacent habitat. Aquatic and marginalareas were sampled using quadrats or releves J and the adjacent habitat described.

The position of aquatic samples, particularlytheir distance from the shore,was dependent on water depth and, insome cases, on the depth of soft substrates. A transect normally extended as far into the lagoonas depth would allow. Sample area J was the area clearly visible from one point.

9 Exposed bedrock 1:v - Swamp Low peart c(I/ Slac k Dominant5(4cPQu5 - Phrd9m;fes ausfra(i5 species codes PdQ5/Slat p«( - 5choenop(ecfu5- Pa/ sfre;no"fani aUS Y.nar/ slat/Ega O D O D D D D D C] O C2j O 0 C7 O 0 O 0 O D C_ _3 L__j Li LI Li L__1 [_._J Li C.-.] Li Li Li C] L_i L_J Li U CU CI

TA-TD : Trunsecfs A - AA '. Points o f chal9e irl avafic/r,aargina( veec N Lough Aconeera, Co.Galway: Shore-based Survey Sections Location of Transects and G

Lough Aconeera G One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage c cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover. G At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic 0 survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres. G At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out, meaning so many 0 metres out from the shore. For the purposes of thissurvey, the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the 0 loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, 0 high water mark, as this is difficult to establish atmany sites.

In the marginal areas through which each transect passed, homogeneousstands of 0 vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For 0 example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0 Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the transect. C

Representative examples of every marginal community encountered during thecourse of the survey were sampled using British National Vegetation Classification(NVC) 0 methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentagecover (using the Domin scale) and the calculation of frequency for each species: E

Cover/Abundance Values 0 Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0 Domin. 10 91-100% 9 76-90 % 8 51-75 % 0 7 34-50 % 6 26-33 % 5 11-25 % 0 4 4-10 % 0 10

ri. Lough Aconeera

3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals

-1 LJ Frequency Values 7 Frequency of each species within the total number of samplesis expressed as follows: LJ Frequency V 81-100 % 7 IV 61-80 % u 111 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communitieswas not available at the time of this survey. Therefore, these communities havenot been determined. LA Swamp communities were determined accordingto the NVC `Swamps and Tall Herb Fen' volume.

L_ Representative examples were usedas there was insufficient time to sample each community at every site where it occurred in thisway. The resulting data are rl presented in an appendix to this report. LI Each aquatic and marginal transect sample is presented herein table form, with a brief J description covering dominant species, standstructure and physiognomy.

The locations of transects within each sitewere selected to represent the degree of J variation therein. Variation in marginalzone floristics, aquatic floristics and shore and aquatic substrate were taken intoaccount. Transects were located at the outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land usewas described in general terms and dominant species J recorded.

2. Shore-based survey: LJ The surveyor walked around the entire shore recording -, aquatic species, marginal communities and adjacent habitats and land u use. The results are presented here as descriptive notes, divided into sections along the shoreaccording to changes in floristics, substrate and/or adjacent habitat. Thesepoints of change are markedon the site maps. r1 Aquatic vegetation was surveyed byuse of the grapnel and by means of wading where u water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site descriptionwas written for each lagoon. j7 11 Lough Aconcera

Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & a Wildlife Service

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0

Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is 0 recorded simply as `Enteromorpha'.

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University 0 College Galway and Michael Guiry, Professor of Botany, University CollegeGalway

Nomenclature C

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of C charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation 0 This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal a communities are taken into account, though particular importance is puton aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as 0 `Valuable', `Potentially Valuable' and Not Valuable'. 0 12 7 Lough Aconeera J

A `Valuable'site is one that is shown to be ofparticular interest and that is considered LI to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following furthersurvey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

7 The fact that this is primarily a shore-basedsurvey and not a full aquatic survey (see LJ `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

15.3.3 Results 1. Shore-based survey

7 Section A-B (Transect A) LJ Aquatic: Ruppia cirrhosa- patchy cover <8m out only Potamogeton pectinatus- sparse <8m out only Enteromorpha- extensive rI Fucus sp.- patchy cover >8m out only u Silt and cobble substrate

Ui Marginal:Open Schoenoplectus lacustris ssp tabernaemontani single speciesswamp. 15m Dense Juncus maritimus with sparse understorey of salt tolerant species. 1-2m

Adjacent:Ulex gallii - Calluna vulgaris- Erica cinerea heath on rocky outcrop with frequent Dabeoica cantabrica

Section B-C

Aquatic: Ruppia cirrhosa- cover unchanged iJ Enteromorpha- cover unchanged

Marginal:Phragmites australis swamp with Cladium mariscus frequenton landward edge. 20-25m

LJ Adjacent:45 degree bank to public road

r, u 13 Lough Aconecra

Section C-D

Aquatic: Unchanged

Marginal:Juncus maritimus with species-poor salt tolerant vegetation as A-B. 3-5m Backing 50cm peat cliff

Adjacent:Heath as A-B

Section D-E

Aquatic: Ruppia cirrhosa - sparse Potamogeton pectinatus- fairly dense, extensive Enteromorpha - fairly sparse Fucus sp. - sparse, <2m out only Chara baltica - sparse

Gravel substrate with frequent cobbles and boulders

Marginal:Exposed bedrock shore- average slope c.40 degrees - with crustose, foliose and fruticose lichens

Adjacent:Unchanged

Section E-F 0 Aquatic: Potamogeton pectinatus Enteromorpha 0 Chara baltica

Marginal:Single species Phragmites swamp. 5m C Backing to lichenous bedrock shore- slope c.70 degrees

Adjacent:Unchanged 0

Section F-G 0

Aquatic: Potamogeton pectinatus Enteromorpha 0 Fucus sp. Chara baltica 0 Marginal:Juncus maritimus and Schoenoplectus lacustris ssp tabernaemontani in a mosaic of mono-dominant stands among scattered boulders. Both as 0 A-B. 4 -8m Backing to bedrock shore as E-F 0 Adjacent:Unchanged 0 14 Lough Aconeera

Section G-H

Aquatic: Unchanged

J Marginal:Juncus maritimus, Schoenoplectus and Eleocharis palustris in small scattered patches - average area c.3m2. 5-10m Backing to lichenous bedrock shore- slope varying c. 15-c.90 degrees

Adjacent:Bog vegetation with dominant Molinia caerulea and frequent Sphagnum spp., Myrica gale, Trichophorum cespitosum, Erica tetralix, Potentillaerecta Heath as A-B occuring on rocky outcrops

Section H-I

Aquatic: Potamogeton pectinatus Enteromorpha Fucus sp.

J Marginal:Unchanged Adjacent:Heath as A-B

Section I-J

Aquatic: Potamogeton pectinatus Ruppia cirrhosa Enteromorpha

Marginal:Unchanged J Adjacent:Unchanged

Section J-K

Aquatic: Ruppia cirrhosa Potamogeton pectinatus- extensive in small sheltered bays only Enteromorpha Filamentous algae Chara baltica- >5m out only

Marginal:Unchanged J Adjacent:Holcus lanatus n - Potentilla anserina pasture u 15 Lough Aconecra 0 Section K-L (Transect B) 0 Aquatic: Ruppia cirrhosa Potamogeton pectinatus Enteromorpha 0 Filamentous algae

Silt and gravel substrate with cobbles 0

Marginal:Sparse Phragmites swamp with sparse aquatics. 3-4m Phragmites dominated swamp with frequent Schoenoplectus. 2-3m 0 Backing to tall dense Phragmites stand with species-poor freshwater understorey. 25-30m 0

Adjacent: Flush vegetation associated with freshwater spring. Juncus effusus and 0 Agrostis stolonifera dominant with abundant Iris psuedacorus, Mentha aquatica, Myosotis scorpioides 0 Section L-M (Transect C) 0 Aquatic: Ruppia cirrhosa- dense beds Potamogeton pectinatus- dense beds Chara baltica- abundant around freswater inflow 0

Marginal:Phragmites dominant with frequent Schoenoplectuson silt substrate.10- 20m 0 Schoenoplectus dominant with frequent low growing Phragmiteson silt substrate. 25-40m. Grazed and poached 0

Adjacent:Heath as A-B and bog vegetation as G-H 0

Section M-N 0 Aquatic: Ruppia cirrhosa Potamogeton pectinatus Enteromorpha 0

Gravel substrate with cobbles and boulders 0

Marginal: 1 m peat cliff with occasional crustose lichen covered bouldersand exposed 0 bedrock. Sparse Phragmites and Schoenoplectus shoots in sheltered areas G Adjacent:Bog vegetation as G-H E 16 u

Lough Aconccra

Section N-O u Aquatic: Ruppia cirrhosa Potamogeton pectinatus Enteromorpha Chara baltica

Marginal:Exposed lichen covered bedrock and boulders with occasional 30-40cm peat cliff Occasional Juncus maritimus tussocks amongst boulders 71 u Adjacent:Bog vegetation as G-H and heath as A-B

Section O-P (Transect D) J Aquatic: Filamentous algae Chara baltica

Silt substrate

Marginal:Fairly dense single species Schoenoplectusswamp. 10-15m Open Schoenoplectus cover over sparse freshwater species. 3-8m

Adjacent:Unchanged n u Section P-Q Aquatic: Ruppia cirrhosa J Potamogeton pectinatus- particularly dense in sheltered bays Filamentous algae n Enteromorpha u Gravel substrate with cobbles and boulders

Marginal: Exposed lichen covered bedrock and boulders with occasional Juncus maritimus and Schoenoplectus in small stands of

Adjacent:Unchanged 7 LJ Section O-R

Aquatic: Ruppia cirrhosa Potamogeton pectinatus rU Filamentous algae J Enteromorpha Chara baltica n Marginal: Exposed lichen covered bedrock and boulders with occasionalJuncus U maritimus tussocks Adjacent:Heath as A-B

17 G

Lough Aconecra 0

Section R-S 0

Aquatic: Unchanged 0 Silt substrate with cobbles and boulders

Marginal:Phragmites dominated swamp with frequent Schoenoplectusas Transect 0 C. 10-15m

Adjacent:Bog vegetation as G-H 0

Section S-T 0

Aquatic: Species unchanged i=i Gravel substrate with cobbles and boulders 0 Marginal:As N-O

Adjacent:Bog vegetation as G-H with heath as A-B 0

Section T-U cJ

Aquatic: Filamentous algae Enteromorpha 0

Marginal:Unvegetated boulder shore 0 Adjacent:Unchanged

Section U-V 0

Aquatic: Potamogeton pectinatus Filamentous algae 0 Enteromorpha

Marginal:Unchanged 0

Adjacent: Unchanged 0

0

0

E 18 r. LJ

Lough Aconeera

Section V-W

Aquatic: Potamogeton pectinatus Filamentous algae tJ Enteromorpha Chara baltica

Marginal: Single species Schoenoplectus swamps-average area c.150m2 - in sheltered bays between small promontories of exposed lichen covered bedrock n Adjacent:Unchanged u Section W-X

Aquatic: Ruppia cirrhosa t__7 Potamogeton pectinatus Enteromorpha

Marginal:As P-Q

Adjacent:Heath as A-B

Section X-Y

Aquatic: Unchanged

Marginal:Open cover of emergent Schoenoplectus, Phragmites and Juncus J maritimus with occasional Schoenus nigricans tussocks. 5-8m Adjacent:Bog vegetation as G-H

Section Y-Z J All as W-X

Section Z-AA

Aquatic: Unchanged

7 Marginal:Mixed Phragmites- Schoenoplectus swamp as Transect C. 6-8m Li Adjacent:Bog vegetation as G-H `1 J n cJ

19 7 Lough Aconeera J

2. Transects U Site: Lough Aconeera Transect code: A

Location: Outlet to sea Sample point: 1 Aquatic -l Om out Sample area: 16m2 (4x4) Substrate: Cobbles Depth: 50 cm Salinit : 14 parts per thousand

NVC communit : ---- Height (cm) Cover 1 TotalPlant 60 LJ Fucus s p. 7 15 40 Enteromor ha 20 LJ 20

Description: Fucus dominant with frequent Enteromorha on rocky substrate.

7 Site: Lough Aconeera Transect code: A Li Location: Outlet to sea Sample point: 2 Aquatic- 5m out Sample area: 16m2 4x4 Substrate:Silt, cobbles n Depth: 50 cm Salinit : 14 parts per thousand U NVC communit :----- Height (cm) Cover TotalPlant J 100 Hi her Plant 20

7 Ru LJ is cirrhosa 40 20 Potamo eton pectinatus 25 < 1

Algae 80

Enteromor ha 20 80

Substrate Cobbles 80 Silt 20

Description: Ruis (including plants in flower and fruit)growing up through extensive cover of Enteromor ha. Potamoeton pectinatus very sparse. rl J

7 U

7 J 21 Lough Aconeera 0

Site: Lough Aconeera Transect code: A EJ Location: Outlet to sea Sample point: 3 Marginal Sample area: 100m2l Ox 10 Substrate:Silt (de-oxygenated)

Depth: 15 cm Salinit : 14 parts per thousand EJ NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp tabernaemontani sub-community Height (cm) Cover EJ TotalPlant 50

EJ Schoenoplectus lacustris ssp tabernaemontani 60 50

0 Description: Open low growing single species Schoenoplectusswamp. 20m. Cover increasing to landward.

Site: Lough Aconeera Transect code: A Location: Outlet to sea Sample point: 4 Marginal Sample area: 1Om2 10x1 Substrate: Silt

Depth: 0 cm Salinit : ----

NVC communit : Undetermined Height (cm) Cover Total Plant 90

Juncus maritimus 70 85 Schoenoplectus lacustris ssp tabernaemontani 70 5 Glaux maritima 6 < 1 Triglochin maritima 10 < 1 Plantago maritima 8 < 1 Samolus valerandi 8 < 1 Chenopodium rubrum 6 < 1 0 Carex extensa 15 < 1 0 Description: Juncus maritimus dominant at densecover with sparse salt tolerant associates in 1 in strip. Backing Ulex gallii- Calluna vulg aris dominated heath with Erica cinerea, EJ Daboecia cantabrica, Molinia caerulea. 0

0

0 22 Lough Aconeera J u Site: Lough Aconeera Transect code: B Location: Swamp associated with spring Sample point: 1 Aquatic - lm out -grapnel 7 Sample area: Grapnel only Substrate: Not known lJ Depth: lm Salinit : 14 parts per thousand NVC communit :----- Height (cm) Cover

Ruis cirrhosa 7 Potamo eton pectinatus LA Enteromor ha Filamentous algae

i LJ

Description:

7 J n Site: Lough Aconeera Transect code: B u Location: Swamp associated with spring Sample point: 2 Marginal Sample area: 20m2 10x2 Substrate: Silt, gravel, cobbles

Depth: 80 cm Salinit : 14 parts per thousand NVC communit :S4 Phra mites australis swam- Phra mites australis sub-community Height (cm) Cover r1 Total Plant 60 u Higher Plant 10

r"1 Phra mites australis 130 5 U Potamo eton pectinatus 50 5 Ruis cirrhosa 15 < 1 J Algae 50

J Filamentous algae 45 Enteromo ha 10 5

Substrate

Silt andravel 90 Cobbles 10 n u Description: Open Phra mitesswamp. Substrate largely covered by mat of filamentous algae and decaying Phra mites material. Sparse low growing Ruis and slightly more extensive, more developed Potamo eton pectinatus with Enteromor ha confinedto cobbles. :::

23 7 Lough Aconeera

Site: Lough Aconeera Transect code: B Location: Swamp associated with spring Sample point: 3 Marginal ci Sample area: 20m2 10x2 Substrate:Silt

Depth: 20 cm Salinit : I 1 parts per thousand ci NVC communit :S4 Phra mites australis swam- Phra mites australis sub-community Height (cm) Cover Total Plant 90 0

Phra mites australis 250 75 Schoenoplectus lacustris ssp tabernaemontani 70 15 0

Descri tion: Fairly dense Phra mitesswamp with frequent Schoenoplectus lacustris. 2m. ci

G

ci Site: Lough Aconeera Transect code: B Location: Swamp associated with spring Sample point: 4 Marginal Sample area: 100m2 10x10 Substrate: Peat 0

Depth: 0 cm Salinit : -----

NVC communit : S4 Phra mites australis swam- Galium palustre su -community Height (cm) Cover ci Total Plant 100

ci Phra mites australis 300 90 E uisetum fluviatile 40 5

L co us euro aeus 30 5 ci Mentha a uatica 30 < 1 Galium palustre 15 < 1 0

Description: Dense Phra mites bedon water-logged sloping ground (c. 15 degrees) with sparse species-poor fen vegetation. 30m. ci Grading to spring flush vegetation dominated by Juncus effusus andAgrostis stolonifera with Iris psuedacorus, Menthaa uatica, Myosotis scor ioides, Lotus corniculatus, C Galium palustre abundant. G

G

0

0 24 U Lough Aconecra J

7 Site: Lough Aconeera Transect code: C Li Location: Freshwater inflow Sample point: 1 Aquatic - 0-200m out- dive Sample area: 0 - 200m out- dive survey rl Substrate: Depth: 1.5 - 2.5 m J Salinit : 14 parts per thousand at 1 m out NVC communit : ----- 7 Height cm Cover LJ Ruis cirrhosa n 100+ Potamo eton pectinatus 200+ u Chara baltica 7 Li Description: Ruis cirrhosa and Potamo eton pectinatus in mixed and singlespecies beds. 7 Continuous cover to 2m depth thenmore patchy cover to 2.5m, unvegetated 2.5- 3m LJ (maximum depth). Temperature inversionat c.2m depth., Chars baltica restricted to < 1.5m on organic substrate in area of freshwater inflow. J

U Site: Lough Aconeera Transect code: C Location: Freshwater inflow --Sample point: 2 Marginal Sample area: 100m2 10x10 Substrate: Silt (de-oxygenated) Depth: 40 cm Salinit : 10 parts per thousand NVC communit : S4 Phra mites australis swam- Phra mites australis sub-community Height (cm) Cover (% Total Plant 85

Phra mites australis 130 80 Schoeno lectus lacustris ssp tabernaemontani J 70 5

Description: Fairly dense Phra mitesswamp with sparse cover of Schoeno lectus.15m.

r-I u

J

n u

25 7

1 Lough Aconeera

0

0 Site: Lough Aconeera Transect code: C Location: Freshwater inflow Sample point: 3 Marginal Sample area: 100m2l Ox 10 Substrate:Silt 0

Depth: 5 cm Salinit : 5 parts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontaniswamp - S.lacustris ssp tabernaemontani sub-community 0 Height (cm) Cover (%) Total Plant 60 0

Schoenoplectus Iacustris ssp tabernaemontani 70 50 Phra mites australis 60 10 G

Description: Open low growing Schoenoplectus dominatedswamp with frequent Phra mites. Both species grazed, substrate poached. 30m. Backing peat bank (c.75 degree slope to 70cm height) withscattered Salix. 0 Backing to Ulex gallii- Calluna vulgaris heath (as Transect A) and Sphagnum - Molinia caerulea- Potentilla erecta bog vegetation. 0

0

Site: Lough Aconeera Transect code: D Location: Marginal swamp Sample point:1 Aquatic - lm out- grapnel Ei Sample area: Grapnel only Substrate: Silt Depth:1 m Salinit : 14 parts per thousand 0 NVC communit : ----- Height (cm) Cover (%) 0 Chara baltica Filamentous algae 0

Description: 0

0

C

C 26

1. u

Lough Aconeera

Site: Lough Aconeera Transect code: D Location: Marginal swamp Sample point: 2 Marginal 7 Sample area: 100m2 10x 10) Substrate: Silt LJ Depth: 5 - 40 cm Salinit : 10 parts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp tabernaemontani sub-community Height (cm) Cover Total Plant 60

Schoenoplectus lacustris ssp tabernaemontani 80 60 rl J Description: Open, fairly low growing single species Schoenoplectusswamp. 15m. n u Site: Lough Aconeera Transect code: D J Location: Marginal swamp Sample point: 3 Marginal Sample area: 50m2 10x5- whole stand) Substrate: Silt and peat

Depth: 0 - 5 cm Salinit : 0 parts per thousand J NVC communit :Undetermined Height (cm) Cover Total Plant 7`t 45 t__! Schoenoplectus lacustris ssp tabernaemontani 80 J H drocot le vulgaris 5 10 Ana allis tenella 1 < 5 r"1 Ranunculus flammula 30 < 1 u Triglochin palustris 10 < 1 Potamo eton natans 5 < 1 Juncus articulatus 20 < 1 Erio horum angustifolium 30 < 1 Eleocharis palustris 20 < 1 Eleogiton fluitans 5 < 1

7 Description: Open cover of Schoenolectus dominant over sp arse freshwater flush Li vegetation. 5m. Grading to Sphagnum spp - Molinia caerulea - Potentilla erecta wet heath vegetation. n u

J 27 EJ Lough Aconeera 0 15.3.4 Evaluation 0 `Valuable'

Chara baltica was found here during the course of thissurvey. This is the first 0 confirmed Irish record for this charophyte species and is groundsin itself for the designation of this site as valuable. It occurs frequently aroundthe site within approximately 10m of the EJ shore and was found in abundance in the vicinity ofthe major freshwater inflow at the western end of the lagoon during a diving survey undertakenby Jim Ryan of the National Parks and Wildlife Service. 0

Ruppia cirrhosa and Potamogeton pectinatus were found growing in densemixed and 0 single species beds at the western end to a depthof about 2.5 metres.

Both species are frequent within ten metres of the shorearound most of the site with G P.pectinatus particularly dense in sheltered bays.

A fucoid species occurs more or less abundantly along therockier southern shores and EI around the mouth of the outlet channel.

Marginal vegetation shows some degree of diversity. The southern andeastern shores 0 are largely exposed bedrock with occasional low peat cliff. Juncusmaritimus dominated saltmarsh vegetation occurs here and along most of thenorthern shore. Schoenoplectus lacustris ssp tabernaemontanioccurs in small occasional stands around 0 much of the site, frequently with Phragmites in sheltered easternbays. Phragmites forms dense beds at the western end, one associated with a freshwater spring and another,with frequent 0 Schoenoplectus, associated with the major inflow stream.

Lough Aconeera is regarded as valuable primarily for thepresence of Chara baltica and 0 for its extensive stands of aquatic macrophytes.

A full aquatic survey is recommended. EJ

EJ

G

G

C

0

0 28 Lough Aconeera

r-1 15.4 ECOTONAL COLEOPTERA u J.A. Good Ph. D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co, Cork

15.4.1 Site Description u Large coastal brackish lake with road-bridge (R 340) and inletchannel (Plate 1) with seawater 7 incursion at high spring tide. Lake shore exposed with boulders,cobbles, coarse sand and peat Li margins (Plate 2). Inlet flood area ofc. 0.5 ha mainly Juncus maritimus dominated vegetation on peaty soil. Lake shore, at least at eastern partof lake, of eroded rock or peat/soil cliffs with J water apparently covering nearly all gradually slopingor bare areas. The relatively large fetch and exposed location of the lake result ina high level of disturbance of the shore. The lackof a sedimentary barrier also reduces habitat availability. 7J Li Subsites (see Fig. 15.4.1)

1. Juncus maritimus (L 878367) Approx. 0.5 ha Juncus maritimus, Puccinellia maritima, Festucarubra, Plantago maritima and Triglochin maritima, grading into Schoenus nigra,on peat. Water in channel from Lough LI Aconeera to sea was c. 3 cm below top ofbank on 28 September 1996 during spring tide n (salinity 11 %o); probably floods Juncus maritmusarea during winter, but with lower salinity due to large outflow from lake. Derelict house walls,stone pathway and drains indicate that LJ this area was probably managed inat least the last century.

7 2. Island in lush (L 878368) Lj Small island of boulders and peat with Pteridium heathwith c. 4m boulders and open water separation from land near bridge. Grassy banks with Festucarubra, Crepis sp. Triglochin J maritima, Plantago lanceolata and P. Maritima./

J 14.4.2 Methods

7 LJ Site Rating using Indicator Species 7 Species rarity or community typicalityare the most frequently used criteria for rating J sites for their biological conservation value. Theapproach in this Coleoptera survey is 7 to use selected species to indicate that sitesare ecologically well-developed with relatively undisturbed naturalprocesses still operating. In particular, it is assumed that LI this is shown by the presence of assemblagesof species which have specialised habitat requirements for habitat features created by physical `1 processes (e.g. aerobic sandflat, washed peat slopes) or biotic LJ responses (algal growth, Scirpus monoculture) to these processes.

As a consequence, the rating is intendedto be of more general ecological value (i.e. indicating ecotonal soil biota), than purelyindicating the presence of rare beetles. r--1 L 29 a

Lough Aconeera 0

Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites. 0

Therefore, species were selectedas indicators of conservation value if: (1) they have a restricted habitat preference toa specific type of microhabitat associated with the lagoon a margins; and, (2) they are reported in the literatureas being local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems. 0 Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following 0 considerations were also taken into account: (1) Whetherthe indicator species was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking intoaccount the number of individuals of a the species present (singletonsare often vagrant); (2) The habitat requirements of the non-indicator species, if they indicatedan anthropogenically disturbed habitat (see Bridge Lough, for instance); (3) Whether the habitat feature might be uniquely created C by the lagoonal conditions (see Lough Tanai, Section14, for instance).

Sites were rated into four categories of conservation value:(1) No recorded value; (2) G low value; (3) average value; (4) exceptional value. Itwould be difficult to defenda categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated ofaverage value if there were less than two indicator 0 species present (see argument in Good and Speight 1992). 0 Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The 0 ratings refer to the terrestrial/ecotonal soil assemblages,and do not represent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.)or herbivorous assemblages (e.g. Lepidoptera). Different indicator speciesare likely to occur in 0 spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relativeinterpretation is based on a reasonably standard sampling effort at each site. Greatersampling effort will 0 probably result in higher numbers of indicator species, butit is assumed that this will not affect the relative rating of sites. G Sampling Strategy At each site representative marginalareas were sampled, including vegetation dominated by Scirpus maritimus, Juncus maritimus, Juncus gerardiand grasses, as well as bare or poorly- e vegetated areas of sand, silt or peat. Particular emphasiswas given to habitat associated with the sedimentary barrier and areas of highest salinity, since much of the habitat associatedwith G freshwater inflows to the interior of the lagoonswould contain a soil fauna not dependenton coastal lagoons. C Sampling Techniques The sampling methods usedare listed in Table 15.4.1. For each site, a Stihl®BR 400 suction 0 apparatus, mounted on the operator's back,was used. This machine (referred to hereafter as 0 30 n i 7 Lough Aconeera LJ n 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter

LJ (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held 7 pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was LJ effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species 7 expected to occur in such a habitat are adapted toclimbing during flooding, these traps were LJ fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 7 LJ

,-1 TABLE 15.4.1. Details of sampling methods. L-1

Method Details No. replicates Sampling period, etc. fl per unit sample LJ

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and plastic funnels; collars used J where cattle/horses occur Cobble samples Cobbles turned 0.5- 2 m 30 7 from water margin LJ Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; agitated soil floated in water

Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during r1 warm weather without rain LJ

Habitat features associated with the sedimentary barrier, suchas shingle cobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are r1 representative of the sites, even if spring speciesmay be absent. LJ Variety of sampling techniques Several techniques will always givea more robust picture of the fauna of a site, LJ because any weather- or site-affected bias inone technique will be compensated by other sampling methods. Some sites did notpossess suitable habitat (peat cliffs, bare

31 0

Lough Aconeera 0 sand, cobbles on sediment, etc.) for flotation, ground searchor cobble search. This is regarded as an absence of habitat, rather thanan unavailable sampling opportunity. 0 That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site. 0 Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is 0 difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all 0 sites (four sets at some sites), of which twowere sorted. There was only one site (Aughinish which has a spring/neap water level variation of>lm) whereflooding limited trap results to only one set. 0

Weather conditions and sampling 0 The suction sampler is very efficient ingrass, rush and sedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather C forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall trapswere placed varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the 0 trap sample appears to be obtained in the first twoweeks.

Quality control: identification C Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens ofmany of the other species have been retained in the author's collection. C

References C Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv. :Mar. Freshw. Ecosyst. 2: 185-208. 0 Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Jr. biogeog. Soc. 14: 48-53. 0

Methods used at this site 0

Carabidae and Staphylinidae (Coleoptera) were recorded from 0 Juncus maritimus area- S-vac suction sampler (7 ix 1996), c. 2 m2; Juncus maritimus area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (7- 28 ix 1996); 0 Island (near bridge) in lough- 6 pitfall traps (7 - 28 ix 1996); Flotation sampling of peat cliff of inlet below road-bridge (7ix 1996). 0

0 32 n Lough Aconcera u Species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associated withthe lagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less n likely to survive in historically degradedecosystems.

L_, 15.4.3 Results

7I LJ Nine species of carabid and thirteen species of staphylinidwere recorded, two species of which are regarded as indicator species (Table 15.4.1). Both Agonum nigrumand Stenus lustrator .1 were recorded from the Juncus maritimus area. LJ

TABLE 14.4.2. Carabidae and Staphylinidae (Coleoptera) recorded from Lough LJ Aconeera. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 7 Li Species No. individuals r-, Carabidae u Abaxparallelipedus (Pill.Mitt.) 3 n Agonum nigrum Dej. 2 Indicator species Bembidion mannerheimi Sahlb. 6 LJ Dromius linearis (01.) 1 n Notiophilus palustris (Duff.). 3 Pterostichus diligens (Sturm) 2 u Pterostichus niger Schall.) 7 n Pterostichus strenuus (Panz.) 1 Trechus obtusus Er. 1 LJ Staphylinidae '-1 Cryptobium fracticorne (Payk.) 1 LJ Geostiba circellaris (Grav.) 8 Lesteva sicula Er. 1

Ocypus olens (Mull.) 1

Quediusfuliginosus (Grav) 1

Quedius molochinus (Grav.) 1

Quedius semiaeneus (Steph.) 1

Rugilus erichsoni (Fauv.) 1 Staphylinus dimidiaticornis Gemm. 1

Stenus brunnipes Steph. 1 Stenus clavicornis (Scop.) 3

.Stenus impressus Germ. 1 * .Stenus lustrator Er. 1 Indicator species

Agonum nigrum is widespread but local in Great Britain (Hymanand Parsons 1992), and has been recorded from Ireland (Speight et al. 1982). Itoccurs on the shores of standing water n (freshwater and brackish) and in bogs (Koch 1989),and its range is restricted to western LJ Europe and the Mediterranean (Freude 1976).

33 0

Lough Aconeera 0 There are three pevious Irish records of Stenuslustrator (Anderson 1984), whichappears to be local in Europe (Horion 1963). The species is tyrphophilous (associated with peat),but 0 also occurs on marshy shores and floodmeadows, according to Koch (1989). The Irish records are from bogs (Anderson 1984), andthe species was also recorded at Faranamanagh Lake and Drongawn Lake in this survey, both of which possess peat margins or adjacent bog. 0 The staphylinid assemblage recorded fromthe Juncus maritimus area had low numbers of species and very low numbers of individuals (Table15.4.2). The species that were recorded 0 were mainly grassland and marsh species (Table 15.4.3).

0

TABLE 15.4.3. Staphylinid assemblage from Juncus maritimusarea, Lough Aconeera 0 (suction sample and pitfall traps combined). 0

Species No. Main biotope 0 Cryptobium fracticorne 1 Peatland

Lesteva heeri 1 Marsh Ocypus olens 1 Grassland 0 Quedius molochinus 1 Grassland Stenus brunnipes I Grassland Stenus clavicornis 1 Grassland Stenus lustrator 1 Marsh C

15.4.4 Evaluation 0

Of low conservation interest for terrestrialecotonal community. C (Rating categories : None, low,average, exceptional]

C Scientific Argument for Rating

The presence of two indicator species indicatesconservation interest, but this cannot be 0 attributed to the lagoonalprocesses, for the following two reasons: (1) Both speciesare associated with surrounding habitats (peatlandand salt-marsh); and (2) their low numbers indicate that the population in the Juncusmaritimus area may be small and derive from these 0 surrounding habitats. Furthermore, thisarea dominated by Juncus marilimus is small relative to other lagoon and bayhead sites. Also, thevery low number of staphylinid individuals and species found here (Table 2)suggest that the area is too disturbed by flooding. Thelake and 0 inlet lack shallow margins toany great extent, and the lake itself has a margindisturbed by wave action, where for the most part itappears that the terrestrial fauna abuts the aquatic fauna with little ecotonal habitat. 0

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15.4.5 References

Anderson, R. (1984) Staphylinidae (Coleoptera) in Ireland- 3: Steninae. Ir. Nat. J. 21: 242- 251. Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus)and the separation of 7: dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist107: 127-133. Horion, A. (1963) Faunistik der Mitteleuropaischen Kafer.IX. Staphylinidae: Micropeplinae bis Euaesthetinae. Feyel, Oberlingen-Bodensee. Freude, H. (1976) Fam. Carabidae. In: Freude, H., Harde,K.W. and Lohse, G.A. (eds). Die Kafer Mitteleuropas. 2. Goecke & Evers, Krefeld. Koch, K. (1989) Die Kafer Mitteleuropas. Okologie. 1. Goecke& Evers, Krefeld. Lohse, G.A. and Lucht, W.H. (1989) Die KaferMitteleuropas.12. 1. Supplementband mit Katalogteil. Goecke & Evers, Krefeld. J Lucht, W.H. (1987) Die KaferMitteleuropas. Katalog. Goecke& Evers, Krefeld.

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15.5 SUMMARY AND EVALUATION

Lough Aconeera is a large (28 ha) natural saline lakewith a natural, partly tidal, inlet. Ji The lake lies close to the edge of a proposedNHA (Site Code 2008) and could be included in that area.

The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion

7-1 LJ Geomorphology Moderate r-1 Aquatic Fauna Moderate

L-1 Vegetation Exceptional Ecotonal Coleoptera Low J Geomorphology.

Lough Aconeera is a natural saline lake witha natural inlet through which seawater enters at all high tides. Tidal range is c. 10cm at neaps and 30 cm at springs. J It is a good example of a large (28 ha)peat lake but differs from others in the region n such as L. Tanai which is shallow and mostly ofpeat, in being somewhat deeper and J having a substratum composed of a larger proportion of bedrockand large boulders. It can be classified as a peat lake with a wide"barrier" composed of peat and rock-This r-1 type is not common in Europe but may correspond tothe "obs" of northern Scotland.

L The lake is rated as of moderate conservation valueas a large, saline lake in good r-1 condition. u Aquatic Fauna

i LJ Among 22 taxa identified, 20 were identified to species andfour are lagoonal specialists. In spite of the high proportion of rocky substrate,burrowing species were 7 well represented e.g. Arenicola marina, Corophium arenarium, Myaarenaria and J Cerastoderma glaucum. Mya arenaria (soft clam), whichwas recorded as juveniles only, was not recorded at any other site during the 7 survey but adults are deep burrowers and could have been overlooked. Gammarus (2 spp.)were particularly J abundant). 7 J The species composition is characteristic of middleto low salinity waters not subject to frequent colonisation from the sea but the absence oflimnic species indicates that there is always a significant marine influence and that thereare no permanent freshwater inflows of significance.

None of the recorded species can be describedas rare in Ireland. J

36 0

Lough Aconecra C

Based on aquatic fauna, the site can be ratedas of moderate conservation value only. C Vegetation C Ruppia cirrhosa and Potamogeton pectinatusgrew in dense mixed and single species beds at the western end to a depth of about2.5 metres and within 10 m of the shore around most of the site with P. pectinatus particularly densein sheltered bays. C

Chara baltica was frequent around the site andwas particularly abundant near a freshwater inflow. This is the first confirmed Irish record forthis species and is C grounds in itself for the designation of this siteas valuable.

Some Fucus was present near the tidal inlet. Marginal vegetationws poorly developed C and consisted ofJuncus maritimus dominated saltmarsh vegetationwith Schoenoplectus lacustris ssp tabernaemontani in small occasionalstands and Phragmites in dense beds near freshwater inflows. 0

The site is rated as of exceptional conservation value forthe presence of Chara baltica. D

A full aquatic survey is recommended. 0 Ecotonal Coleoptera 0 Nine species of carabid and 13 species of staphylinidwere recorded, two species of which are regarded as indicator species, both from the Juncus maritimusarea. ri u Agonum nigrum is widespread but local in Great Britain andhas been recorded from Ireland. It occurs on the shores of standing water (freshwater and brackish)and in bogs and its range is restricted to western Europe and the Mediterranean. 0

There are three pevious Irish records of Stenus lustratorwhich appears to be local in Europe. 0 The species is tyrphophilous (associated with peat), but alsooccurs on marshy shores and flood meadows. The Irish recordsare from bogs. The species was also recorded at Faranamanagh Lake and Durnesh Lough in thissurvey, both of which possess peat margins or 0 adjacent bog.

Summary 0 Lough Aconeera is a good example ofa large, natural saline lake in peatland with a natural tidal inlet and a substrate comprisinga large proportion of bedrock.. Li

The aquatic fauna was typical ofa lagoon in the middle to low salinity range andincluded four lagoonal specialists but the only species of interestwas the soft clam, Mya arenaria. 0

The aquatic vegetation was well developed and remarkable chieflyfor the presence of the rare lagoonal specialist Chara baltica. Marginal vegetationwas poor. P

0 37 J n Lough Aconecra u Although two indicator species of ecotonal Coleoptera wererecorded, theirpresence cannot be attributed to lagoonal processes. Stands ofJuncus maritimus in which thespecies occurred were small and staphylinid numbers were low.

Overall, the lake is rated as of exceptional conservation valuefor the presence of Chara baltica, but in other respects its rating is only moderateto low.

Designation as a proposed SAC is recommended.

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7 COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

16. MILL LOUGH

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

Prepared for the National Parks and Wildlife Service

(BioMar,Life) J

16. MILL LOUGH

J CONTENTS 16.1 Study Area

16.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

16.2.1 Methods 16.2.2 Results UI 16.2.3 Discussion 16.2.4 Threats 16.2.5 Evaluation 16.2.6 References

16.3 Vegetation Survey (Pat Hatch)

16.3.1 Site Description 16.3.2 Methods 16.3.3 Results Shore based survey Transect tables 16.3.4 Evaluation

16.4 Ecotonal Coleoptera (Jervis Good)

16.4.1 Site description 16.4.2 Methods 16.4.3 Results 16.4.4 Evaluation 16.4.5 References

16.5 Summary and Evaluation

J Mill Lough

16. MILL LOUGH, Co. Galway. i OS Grid Reference: L 755 331, 1:50,000 Sheet No. 44 Alternative names: Loch an Mhuilinn J 16.1 STUDY AREA

General features Mill Lough is situated in the north of Ard Bay,western Connemara, 4 km west of Carna (Fig. 16.1.1). The lake lies in an area ofrock and peat and has a short outlet to J the sea under a bridge at the southern end. Thebed of the lake is mostly composed of granite bedrock and detached blocks and boulders, with patches ofcoarse sand and unconsolidated peat in the sheltered areas. A freshwater streamenters the lake in the northeast and there are numerous small springs discharging groundwaterto the lake from the surrounding areas of peat. Mill Lough is included as a good example ofa type of lagoon, similar to the Scottish "obs", which are characteristic of parts of the west coastof Ireland, especially in Connemara. They are permanent, shallow and brackish, with restricted tidalinfluence due to the presence of a "barrier" of peat, andin this case rock. These "peat" lagoons are of particular interest as very little appears to beknown about any aspect of the functioning of brackish lagoons situated in acid peatbogs. Very little is known about the lake. Itappears to have no protective status but does not appear to be under any immediate threat. J Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is 5.6 °C in Januaryand 14.3 °C in July. The growing season (the period of mean daily air temperatures above 6°C) is 8.5 months and as J snow and frosts are rare, some plant growth is possiblein winter months. Annual rainfall is approximately 1200 mm, and the number of raindays (1 mm or more) is around 180. Winds are mainly from the southwest. Mean annualhourly wind speeds J are between 5 and 6 m/s and a maximum windspeed of 50 m/s is estimated to occur once in 50 years. The daily duration of bright sunshineaverages 3.5-4 0 hours. Mean relative humidity is around 85% ason all Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8in (Carter 1992). Maximum wave heights (averaging once in 50 years) are 30-35 in(Couper 1984). Tides are semi- diurnal and the tidal range (MHWS-MLWS) at Kilkieran is 4.2in (Admiralty Tide J Tables). Sea temperatures are lowest in February (around 7°C) andhighest in August (14.6°C).

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Fig. 16.1.1Section of 150 000 map showing locality of Mill Lough jn Mill Lough Landscape and Geology The Connemara region of Galway is a glaciated plain of rolling lowland with granite outcrops and Atlantic type blanket bog.The granite bedrock is impervious and drainage density is high. Soils otherthan peat are shallow 7 podzols with very limited land-use capability (Royal Irish Academy 1979).The area J was described by Haughton (1957) as a "wilderness of barerock, glacial erratics, water and peat". rl Land surrounding the lough consists of small irregular fields ofsemi-improved pasture, j bare rock, small peatbogs and wet heathland.

Lake Topography The lagoon is approximately 400 in from north to south,350 in from west to east at its widest point and coversabout 5 ha. Water depth is 1- 2 in over most of the lake. There is a deeper poolof 4-5 in at the southern end which, according to local information, was created by blasting and anotherdeeper area in the northwest (2-3 m). The bed of the lake is mostlycomposed of granite bedrock and detached blocks and boulders, with patches of coarse sandor unconsolidated peat and silts in the sheltered areas. Reedbeds of Phragmites have becomeestablished in the small bays. It is possible that peat was once cut in thearea occupied by the lake. The channel connecting the lake to the sea runs through rock andpeat and appears to be natural, but may have been modified to allow small boats toenter the lake.

Hydrology A freshwater stream enters the lake in the northeast andundoubtedly J freshwater also enters through the slow release of groundwater fromthe saturated peat higher in the valley and also in direct rainfall. Seawaterappears to enter on most tides, through the channel which leads under the bridge. Atidal range in water level of 1.3 in was measured at the bridge on 29.ix.96. Aseasonal pattern is likely, whereby water levels rise in the winter with the increased rainfalland storm frequency, and gradually decline in the summer. The peaty soils of thesurrounding land would, however, through absorption and slow release of water, affect thedelivery time of both surface- and ground-water flows to the lake.

Salinity and water quality Despite the fact that seawater appears to enter on every tide the lake is also likely to receive large volumesof freshwater runoff from the surrounding land. Salinity levels are likely to vary considerably, bothspatially and temporally, depending on precipitation and tides. Generally, salinity levelsare likely to be relatively high throughout the year with a tendency toincrease during the summer. J However, the peaty soils would affect the flow of bothsurface- and ground-water to the lake. The prolonged flow of freshwater to the poolduring the "dry" months may result in lower salinities than might be expected. On theother hand, winter storms may result in a higher volume of seawater entering the lakeand raising salinity levels at a time when they might be expected to fall.

Stratification is only likely to occur for any prolonged periodin the deeper pool as the high tidal exchange in a relatively small basin wouldcause mixing on a regular basis. The surrounding land is relatively natural and even grazing landis likely to receive only limited fertilizer applications. Water quality appears to be high althoughquite a deep n J 2 1 U

Mill Lough 0 layer of organic silt has accumulated in some areas ofthe lake and there is some evidence of pollution in the northwest corner which has beenused as a dumping area 0 for domestic refuse from nearby houses and farms. The regularflushing of the lake would restrict any serious problems caused by eutrophication. ri

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16.2 AQUATIC FAUNA Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin n J 16.2.1 Methods n Environmental variables J Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., I %o precision). A photographic record was made of the site andlocal information sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples J were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations A and D inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic rl variables including season, state of the tide, weather, nature ofthe habitat and life J cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by

4 u

Table 16.2.1. Fauna Recorded in Mill Lough, Co. Galway. Juneand September 1996. 0

Fauna Sampling Stations ( L.T. = light-trap) A L.T. B L.T.B CL.T.C D L.T. 0 Porifera Cnidaria Dynamena pumila + Turbellaria 0 Nemertea Annelida Arenicola marina + Hediste diversicolor 1 1 0 Crustacea Cirripedia Mysidacea Leptomysis lingvura 1 0 Neomysis integer c 35 a 500 c clOO c clOO Praunusflexuosus 1? Isopoda Jaera nordmanni c o 0 Lekanesphaera hookeri 40 c ? + 1 c 23 Amphipoda Corophium volutator c Gammarus duebeni + 0 G. zaddachi + + + Tanaidacea Decapoda Carcinus maenas + + F, 5 c 0 Palaemon elegans o P. serratus F, 1 Palaemonetes varians o o c C 4 0 Insects Ephemeroptera Plecoptera 0 Trichoptera Odonata Hemiptera EJ Coleoptera *Cercyon littoralis Diptera Chironomidae c o C o 0 Molluscs Prosobranchia Hydrobia ulvae 5 7 Littorina obtusata 1 0 Potamopyrgus antipodarum 1 + 1 Opisthobranchia Pulmonata 0 Bivalvia Cerastoderma glaucum c c Bryozoa Conopeum seurati + + + + Flustrellidra hispida + 0 Echinodermata Tunicata Ascidiella scabra + Teleostei Anguilla anguilla F, 2 + + 0 Gasterosteus aculeatus o 1 o 3 + c Labrus bergylta F, 1 Mugilidae F, 12 0 Platichthysflesus F, 1 0 Pomatoschistus micros o o 3 o 1 0

+ = present; o = occasional; c = common; a= abundant; F = fyke net. 0 * = Station not known - see text 0 Mill Lough

inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are purely subjective, and absolute numbers vary between taxa. J Several faunal groups were sorted and distributed to specialists forconfirmation. Standard keys were used to identify remaining specimens, but manyof these were larval or juvenile stages and difficult to identify with certainty.Some groups require adult males for identification and these were often not availabledue to low population density and the limited number of individuals collected in thetime available (eg Jaera, hydrobiids). All Diptera are identified to family level.

16.2.2 Results

NO Lough was sampled on 12.vi.96 during the first partof the survey, and from 27- 29.ix.96 during the more intensive survey. Positions of the sampling stations are shown in Fig. 16.1.1.

Environmental Variables Station A (OS 7559 3285) was located at the southernend of the lake nearest to the road and the outlet channel which runs under the bridgeand is the most tidal area of the lake. Water depth varied from 0 - 80 cm,substrate was smooth slabs of granite bedrock, stones of various sizes and small pockets of gravel,coarse sand, silt and peat. Salinity measured 31 %o. Station B (OS 7543 3308) was located in the northwestcorner near a Phragmites bed and area used for domestic refuse. Water depth was0 - 60 cm, substrate consisted of soft organic mud and unconsolidated peat with occasional stonesand salinity measured 34%0. Station C (OS 7556 3319) was located in the northeastcorner where a stream enters

the lake, in a bed of Phragmites.Water depth was 0 - 1 m, substrate was rock,stones, coarse granite sand and organic silt/mud. This station was themost affected by freshwater inflows and salinity measured 2 - 6%0. A fykenet was used a short distance offshore in this area where water depth was 2-3 mand salinity may have been considerably higher at depth. Station D (OS 7567 3309) was located in the bayat southeast corner of the lake. Depth varied from 0 - 1.5 m, substrate was rockwith unconsolidated peat and soft organic mud. Salinity measured 20%0.. Station E (OS 8769 3714) was located on the northeastshore among Phragmites. J Water depth varied from 0 - 1.2 m., substrate consistedof coarse granite sand, organic silt and fibrous roots, and salinity measured 12%0. J Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 16.2.1. Among 30 taxa listed, 28 are identified tospecies. The list comprises 9 marine species, 4 poly-mesohaline, 13 euryhaline, 1 oligo-mesohaline, and 1limnic J

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Mill Lough 0

species (Table 16.2.2). Four species are listed as a lagoonalspecialists in Britain (Davidson et al. 1991 ). 0

Table 16.2.2 Ecological categories of the recorded taxa in NOLough.L = lagoonal 0 specialist according to Davidson et al. (1991).

Marine Dynamena pumila Leptomysis lingvura iJ Palaemon elegans P. serratus Hydrobia ulvae 0 Littorina obtusata Flustrellidra hispida Ascidiella scabra 0 Labrus bergylta

Poly-mesohaline Arenicola marina Praunusflexuosus 0 Corophium volutator Cerastoderma glaucum L 0 Euryhaline Hediste diversicolor Neomysis integer Lekanesphaera hookeri L Jaera nordmanni 0 Gammarus duebeni Gammarus zaddachi Palaemonetes varians L 0 Carcinus maenas Conopeum seurati L Anguilla anguilla 0 Gasterosteus aculeatus Pomatoschistus microps Platichthysflesus 0 Oligo-mesohaline Potamopyrgus antipodarum

Limnic Cercyon lateralis 0

The greatest number of species was recorded at A, nearestto the sea inlet, which was iJ the only station where some marine and polyhaline species werefound (e.g. Praunus flexuosus, Palaemon elegans, Littorina obtusata, Hydrobia ulvae, Ascidiella scabra). Potamopyrgus antipodarum replaced Hydrobia ulvae in other parts of thelake and 0 was the most abundant species at C where a freshwater stream enters. The commonest species at all stations were Neomysis integer, Lekanesphaera hookeri andchironomid larvae. 0

16.2.3 Discussion 0 The species assemblage typifies a brackishwater with a sea inletand salinity in the main body of the lake in the medium to high salinityrange. The scarcity of oligohaline 0 species indicates that high salinities are too frequent to allowtheir survival, while the

0 6 0 Mill Lough

absence of barnacles and other sedentary marine species suggests thatfrequent low salinities also occur. There is evidence for this as inJune 1996 the salinity at D was only 2%o. A few sedentary marine species were present e.g.Flustrella hispida and Ascidiella scabra, but they were represented by few individuals. J None of the recorded species can be described as rarein Ireland. 16.2.4 Threats

Refuse is dumped on the shore of the lake atone point.

Local inhabitants have noted a decline in the fish populationwhich they attribute to agricultural runoff and domestic sources from small farms on anearby hillside. J 16.2.5 Evaluation

Mill Lough is a natural saline lake with a naturaltidal inlet.

It is an example of a lake of a type,probably also frequent in Scotland, which can be classified as a saline peat lake. It differs from L.Aconeera in being smaller, with less rock and a greater tidal exchange. As little appears tobe known about the functioning of peat lakes, this one may be worthy of furtherstudy but it is a different type from the more shallow, dominantly peat lagoons such as L. Tanai.

The aquatic fauna was typical of a lagoon with asignificant tidal inflow and a medium to high salinity. The component of marine species was thereforegreater than in L. Aconeera. Localised areas of low salinity allow some oligohaline speciesto survive.

No rare or interesting species was recorded.

The lake does not lie in or near a proposedNHA.

In conclusion, as a result of the aquatic faunal survey,Mill Lough is rated as having a relatively low conservation value. It is not a true lagoonbut is geomorphologically interesting.

7 LJ

Mill Lough LJ

16.2.6 References and Additional Sources of Information 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation 0 appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. 0 Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N. C. et al.1991. Nature conservation and estuaries in Great Britain. LJ Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Haughton, J.P. 1957. Physiography and Climate. In: Meenan, J. &D.A. Webb.(eds.) 0 A View of Ireland. Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine 0 crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. 0 Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, LJ Vol. 1,Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. EJ Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. 0 Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the 0 Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. lJ

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Plate 162.1View across Mill Lough from the western shore, looking towardStation D. r r

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r Plate 16.2.2View of ebb tide flowing from Mill Lough from StationA. No m r r

Plate 16.2.3 View of northwestern area of Mill Lough, StationB. to

No

71

10 Plate 16.2.4 View of refuse in northwestern area of MillLough, near Station B. J

Mill Lough

16.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

16.3.1 Site Description(Fig. 16.3.1)

This is a rocky site set in a `rolling' landscapeof low hills. The area surrounding the lagoon is largely dominated by heath vegetation with frequent rockoutcrops and is subject to grazing. A fairly extensive area of Juncus maritimusdominated vegetation lies to the north east of the lough.

The shores are largely exposed bedrock and boulders with occasionalpeat shores of shallow slope.

The major freshwater inflow enters the lagoon to the northeast. Open Phragmites swamps occur here and in bays and other more orless sheltered areas in the north west and east. These are nowhere extensive.

The outlet to the sea joins the lough at itssouthern tip, passing beneath a road bridge which runs close to the south eastern shore.

16.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 16.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

J One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

9 0

0 KEY: p - Lxrose4 bedrock 0 - 5wamp Fen i 0 0 pom"Marif Species cede;

Paus 1, Ti'ngr- 0 8 ,i Tiler- J-u,iw 5 gerard; i 0 8 0

a e 0 i i B

PdUS 8 1' rrilar mdY 0 Pausi TMar i

8

Tmar, .Tmar 0 Tmar/fger Paus

Tow 0

0 XoldY 0

0 ;ah Water Mork 0

0

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Fig. 16.3.1 0

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0 TA-TO: l"ra l 5 e ct5

A -a = Po;nf5C71 chd/lyeivl c(7ual"iGlYYlar9InaI ve7efdfTovh J

J

J

MCI 163.2 MillLough, Co.Galway: Location of Transects and Shore-based Survey Sections

J

l u

Mill Lough 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel 0 survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, of course, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for 0 other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the 0 transect. 0 Representative examples of every marginal community encountered during thecourse of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Don-in scale) and the calculation of frequency for each species: 0 Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Don-in. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 6 26-33 % 0 5 11-25 % 4 4-10 % 3 <4 % -many individuals 0 2 <4 % -several individuals 1 <4 % -few individuals 0

0

10 J

Mill Lough

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % J IV 61-80 % III 41-60 % II 21-40 % J I 1-20 %

7 Note: The NVC volume covering saltmarsh communities was not availableat the time Li of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall J Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey: n J The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

Constraints J Time. Restrictions on the time available in which to carryout this survey had the following consequences:

11 0

Mill Lough 0 a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications 0

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of 0 charophytes are according to N.F. Stewart.and J.M. Church, `Red DataBooks of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection. 0

0

12 Mill Lough

A `Potentially Valuable' site is one which this survey indicatesmay be of interest and which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

16.3.3 Results 1. Shore-based survey

J Section A-B (Transect A)

7 Aquatic: Enteromorpha - extensive u Filamentous algae - sparse Fucus sp. - patchy

Gravel substrate with cobbles and boulders

Marginal:Open cover of low Juncus maritimus tussocks over salt tolerantspecies dominated by Juncus gerardii and Agrostis stolonifera on peat substrate. 3-15m Grazed and poached

Adjacent:Ulex gallii - Molinia caerulea- Potentilla erecta heath with frequent Daboecia cantabrica u7 Section B-C

Aquatic: Ruppia cirrhosa Enteromorpha Filamentous algae Fucus sp.

Marginal:Unchanged

Adjacent:Unchanged J n u

13 0

NO Lough 0

Section C-D (Transect B) 0 Aquatic: Ruppia cirrhosa- sparse, low growing Enteromorpha - extensive mat, free floating Filamentous algae- patchy a

Silt substrate 0 Marginal:Dense Phragmites swamp with sparse Ruppia and free floating filamentous algae. 5-10m 0 Grading to species-poor salt tolerant community with fairly dense coverof Juncus 0 maritimus tussocks and patchy Agrostis stolonifera dominant below. 5- 100m. Grazed and poached 0 Adjacent:Unchanged

0 Section D-E (Transect C)

Aquatic: Ruppia cirrhosa- sparse, low growing 0 Enteromorpha- extensive, free floating

Marginal:Open Phragmites dominated swamp with frequent Schoenoplectus a lacustris ssp tabernaemontani. 4 -5m Grading to open cover of Schoenoplectus and Juncus maritimus with 0 Eleocharis palustris and Agrostis stolonifera co-dominant below among salt tolerant species. c.20m 0

Adjacent: Iris psuedacorus dominated flush community with frequent Juncus effusus, 0 Mentha aquatica, Filipendula ulmaria and Lotus corniculatus.

Section E-F 0 Aquatic: Ruppia cirrhosa Filamentous algae 0

Gravel substrate with cobbles and boulders 0 Marginal:Exposed bedrock and boulder shore with crustose, foliose and f-uticose lichens. Occasional small patches of Juncus maritimus salt tolerant community as D Transect A

Adjacent:Heath as A-B 0

0 14 0 Mill Lough

Section F-G (Transect D)

Aquatic: Ruppia cirrhosa - sparse Filamentous algae - extensive

Silt substrate with cobbles

Marginal: Sparse Phragmites swamp growing through dense filamentous algae cover with sparse Ruppia in sheltered bays. 7 Backing to Juncus maritimus salt tolerant community. c. 10m at LJ bayheads, c.200m east of freshwater inflow, 1-2m strip elsewhere

Adjacent:Bog vegetation at bayheads. Dominant species Molinia caerulea, Schoenus nigricans, Myrica gale, Sphagnum spp. n Heath as A-B elsewhere J Section G-H rl As E-F

M Section H-I UI Aquatic: Ruppia cirrhosa Filamentous algae Fucus sp.

Marginal:Unchanged

Adjacent:Unchanged

Section I-J

Aquatic: Ruppia cirrhosa Filamentous algae

Marginal:Juncus maritimus dominated salt tolerant community as Transect A. 1-5m

Adjacent:Unchanged

Section J-K

Aquatic: Ruppia cirrhosa Filamentous algae Fucus sp.

Marginal:As E-F

Adjacent:Unchange

15 Mill Lough 0

Section K-L 0 Aquatic: Ruppia cirrhosa Filamentous algae 0 Marginal:As I-J with occasional boulders and exposed bedrock 0 Adjacent:Unchanged

0 Section L-M

Aquatic: Ruppia cirrhosa 0 Filamentous algae Fucus sp. 0 Marginal:Exposed bedrock shore with crustose, foliose and fruticose lichens

Adjacent:Unchanged 0

Section M-N

Aquatic: Ruppia cirrhosa a Filamentous algae

Marginal:Juncus maritimus dominated salt tolerant community as Transect D. c.150-200m 0

Adjacent:Unchanged 0 Section N-O 0 As E-F

0

Section O-P 0 Aquatic: Unchanged

Marginal:Open Phragmites swamp with sparse low growing Ruppia. 15-20m 0 Backing to Juncus maritimus dominated community as Transect D. 5-15m G Adjacent:Dry stone wall Public road 0

0

16 0 Mill Lough n U Section P-Q n Aquatic: Ruppia cirrhosa J Filamentous algae Fucus sp. - sparse

Marginal:Juncus maritimus strip - 1-4m - almost continuous with scatteredlichen covered boulders and bedrock outcrops forming shore in places.

Adjacent:Heath as A-B n J Section Q-R Aquatic: Unchanged

Marginal: Open single species Phragmites swamp. 10-15m Backing to Juncus maritimus dominated community as Transect D. 3- c.50m

Adjacent:Unchanged n J Section R-S

Aquatic: Species unchanged Fucus now more extensive 7 J Marginal:As P-Q Adjacent:Unchanged

rl J Section S-T

Aquatic: Filamentous algae Enteromorpha Fucus sp. 7 J Marginal:Unchanged

Adjacent:Unchanged n J

17 J

Mill Lough

2. Transects J Site: NO Lough Transect code: A

Location: Outlet to sea Sample point: 1 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Gravel, cobbles, boulders

Depth: 5 - 20 cm Salinit : 21arts per thousand

NVC communit : ----- Height (cm) Cover Total Plant 100 J Enteromo ha 10 70 Filamentous algae 20 Fucus s p. 10 10

Description: Enteromo ha dominant with fre uent filamentous algae and Fucus on roc substrate.

Site: Mill Lough n Transect code: A Location: Outlet to sea Sample point: 2 Marginal J Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 75

Juncus maritimus 50 50 Juncuserardii 25 10 A rostis stolonifera 10 10 Glaux maritima 6 5 Aster tri olium 15 < 5 Tri lochin maritima 15 < 1 Planta o maritima 10 < 1 Leontodon autumnalis 15 < 1

Description: Open cover of low Juncus maritimus tussocks over salt-tolerant community dominated b Juncuserardii and A rostis stolonifera. 10m. Poached andrazed. Grading to Ulexallii - Molinia caerulea- Potentilla erecta heath with Daboecia J cantabrica.

J

19 1 0

Mill Lough 0

Site: Mill Lough Transect code: B 0 Location: Marginal swam Sampleoint: 1 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Silt 0 Depth: 50 cm Salinit : 21arts per thousand NVC communit :----- Height cm Cover 0 Total Plant 100 FE her Plant < 1 0 Ruis cirrhosa 20 < 1

Algae 100 0

Enteromo ha 80 0 Filamentous algae 20

0 Description: A mat of free floating al ae with verysparse, mostly low growing Ruia. Several Ruis plants in flower and fruit. 0

0 Site: Mill Lough Transect code: B Location: Marginal swam Sample p oint: 2 Marginal 0 Sample area: 100m2 10x10 Substrate:Silt

Depth: 0 - 15 cm Salinit : 20arts p er thousand NVC communi : S4 Phra mites australis swam- Phra mites australis sub-community 0 Hei ght cm Cover Total Plant 100 Higher Plant 90 0

Phra mites australis 160 90 0 Ruis cirrhosa 10 < 5

Algae 30 0

Filamentous algae 30 0

Description: Dense Phra mites swam with sparse low g rowingRuis and free floating algae l Om. 0

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0 20 Mill Lough

Site: Mill Lough Transect code: B Location: Marginal swam Sampleoint: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Hei ht cm Cover Total Plant 90

Juncus maritimus 60 70 Phra mites australis 40 5 A rostis stolonifera 20 10 Puccinellia maritima 10 < 5 Aster tri olium 20 < 5 Glaux maritima 8 < 5 Tri lochin maritima 10 < 1 Planta o mantima 8 < 1

Description: Juncus maritimus dominantover s pecies-poor salt tolerant vegetation. 100m. Grazed. Substrate poached and water-logged. Grading to Ulexallii - Molinia caerulea- Potentilla erecta heath.

Site: NO Lough Transect code: C

Location: Swam associated with spring Sample point: 1 Aquatic - 3m out Sample area: 16m2 4x4 Substrate: Silt

Depth: 45 cm Salinit : 16arts per thousand NVC communit :----- r1 Height cm Cover J Total Plant 100 Hi her Plant < 5

Ruis cirrhosa 20 < 5

Algae 100

Enteromo ha 100

Description: Sparse low growing Ruis with extensive cover of free floating Emteromor ha

21 u

Mill Lough 0

0 Site: Mill Lough Transect code: C Location: Swam associated with spring Sample point: 2 Marginal 0 Sample area: 24m2 6x4 - whole stand Substrate: Silt

Depth: 0 - 45 cm Salinit : 11arts per thousand NVC communit :S4 Phra mites australis swam- Phramites australis sub-communit 0 Height cm Cover Total Plant 60

Phra mites australis 150 40 Schoeno lectus lacustris sstabernaemontani 100 20 0

IDis::C:rition: Open Phra mites dominated swam with frequent S. lacustris.4m. 0

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Site: Mill Lough Transect code: C Location: Swam associated with spring Sample p oint: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- Agrostis stolonifera sub-community Hei ght cm Cover Total Plant 100

Schoeno lectus lacustris sstabernaemontani 60 25 Juncus maritimus 50 25 Eleocharisalustris 30 20 A rostis stolonifera 15 20 Juncuserardii 20 5 Glaux maritima 8 5 Cochlearia an lica 6 < 1 Tri lochin maritima 15 < 1 Planta o maritima 10 < 1 Samolus valerandi 10 < 1 Carex otrubae 40 < 1

Description: Open cover of Schoeno lectus and Juncus maritimus withEleocharis and A rostis co-dominant below among salt tolerant species. 20m. Grading to Irisseudacorus dominated community with frequent Juncus effusus, Mentha a uatica, Fili endula ulmaria, Lotus corniculatus.

Site: Mill Lough Transect code: D Location: Freshwater inflow Sample point:1 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Bedrock, silt

Depth: 80 cm Salinit : 4arts per thousand NVC communit :----- Height cm Cover Total Plant 5

Ruis cirrhosa 50 5

Description: Sparse Ruis only.

23 u

Mill Lough 0

Site: Mill Lough Transect code: D 0 Location: Freshwater inflow Sample point: 2 Marginal Substrate: Silt Sample area: 20m2 10x2 0 Depth: 20 - 50 cm Salinit : 4arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover 0 Total Plant 60

Phra mites australis 150 60 0

Descri tion: Open single species Phra mites swamp. 3m. 0 Backing 50cm eat cliff. 0

0

Site: Mill Lough Transect code: D Location: Freshwater inflow Sample point: 3 Marginal 0 Sample area: 16m2 4x4 Substrate: Peat

Depth: ----- Salinit : ----- NVC communit :Undetermined 0 Height cm Cover Total Plant 95 a

Juncus maritimus 60 50 Schoenus ni ricans 40 20 0 A rostis stolonifera 15 15 Juncuserardii 15 10 Festuca rubra 15 5 0 Glaux maritima 8 < 5 10 < 1 Planta o mantima 0 Leontodon autumnalis 20 < 1 Samolus valerandi 8 < 1 Carex extensa 15 < 1 0

Description: Open cover of Juncus maritimus tussocks with Schoenus niricans locally 0 co-dominant. Patch cover of A rostis stolonifera and Juncuserardii among round layer of otherwise sparse salt tolerant s pecies. c.200m. Backing to Ulexallii - Molinia caerulea - Potentilla erecta heath 0

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24 0 Mill Lough

J 16.3.4 Evaluation

`Potentially Valuable'

This is a rocky site with a high degree ofspatial salinity variation at time ofsurvey (5 parts per thousand in the sheltered bays of thenorth east and south east, 21 parts per thousand around the mouth of the outlet channel andalong the western shore).

A Fucus species has a fairly wide distribution, occurring frequentlyalong the rocky shores of both the east and west to within approximately100 metres of the main freshwater inflow.

Ruppia cirrhosa occurs around the whole site.It has a sparse cover near the shallower shores and was not found in dense beds in thissite.

Some Zostera fragments were found washedup on the shore in places.

J Marginal vegetation is more or less uniform. Juncus maritimus salttolerant community is dominant between stretches of bedrock shore. Smallopen Phragmites swamps occur in sheltered areas of the north and south east.

Mill Lough would seem to be a species-poor site withno particularly notable aquatic species. However, Ruppia cirrhosa is frequent to abundant and, bearingin mind the restricted nature of aquatic survey at this site,a more in depth survey could well yield more interesting results.

Full aquatic survey is recommended.

25 Mill Lough

16.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES, Terrascope Environmental Consultancy, Riverstick, Co. Cork

16.4.1 Site Description

Coastal brackish lake with road-bridge and short inlet channel, withseawater incursion at high spring tide. Lake shore exposed with boulders, cobbles and peatysoil margins. Flood areas of c. 0.05 ha mainly Juncus /grass and mostly submergedPhragmites bedson peaty soil on more sheltered western shore.

Subsites (see Fig 16.4. 1)

1. Juncus maritimus (L 755328) Approx. 0.05 ha Juncus maritimus, Juncus gerardi, Puccinellia maritima, Armeriamaritima, Plantago maritima and Triglochin maritima on peat. Salinity of waternear shore was 12 %o, J and the area was completely flooded by spring high tidein late September 1996. The area is grazed by cattle.

2. Juncus erg ardi (L 755329) Approx. 0.03 ha grass sward with Juncus gerardi near Ulexgalii herb-rich heath/grassland. Partly flooded at high spring tide (evidence from flooded traps).

3. Inlet margin (L 755328) J Lake shore at inlet riffle area, with broken angular rocks,cobbles and pebbles on coarse sand/organic substrate. Unvegetated area, flooded at high spring tide. Theisopod Ligia oceanica and amphipods abundant.

16.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physicalprocesses (e.g. aerobic sandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

26 u

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Fig. 16.4.1 Map of sampling sites (Carabidae and Staphylinidae) atMill Lough, Co. Galway 0 I- Pitfall traps 2 - Pitfall traps, S-vac 3 -Cobble search 0

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0 Mill Lough

Therefore, species were selectedas indicators of conservation value if: (1) they have a restricted habitat preference toa specific type of microhabitat associated with the lagoon margins; and, (2) they are reported in the literatureas being local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whetherthe indicator specieswas likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking intoaccount the number of individuals of the species present (singletons are often vagrant); (2) Thehabitat requirements of the non-indicator species, if they indicatedan anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitatfeature might be uniquely created by the lagoonal conditions (see Lough Tanai, Section14, for instance).

Sites were rated into four categories of conservationvalue: (1) No recorded value; (2) low value; (3) average value; (4) exceptional value.It would be difficult to defend a categorization of sites intoany finer categories than this (see Foster et al. (1992),for instance). Sites were not rated ofaverage value if there were less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data usingstandardised sampling methods. The ratings refer to the terrestrial/ecotonal soilassemblages, and do not represent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera,etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicatorspecies are likely to occur in spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species andtheir relative interpretation is based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicatorspecies, but it is assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginalareas were sampled, including vegetation dominated by Scirpus maritimus, Juncus maritimus, Juncus gerardiand grasses, as well as bare or poorly- vegetated areas of sand, siltor peat. Particular emphasis was given to habitat associated with the sedimentary barrier andareas of highest salinity, since much of the habitat associatedwith freshwater inflows to the interior of the lagoonswould contain a soil fauna not dependenton coastal lagoons. J

Sampling Techniques The sampling methods usedare listed in Table 16.4.1. For each site, a Stihl®BR 400 suction apparatus, mounted on the operator's back,was used. This machine (referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suctionsampler) has a suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects)of 100 x 1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held

27 l u

Mill Lough 0 pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was 0 effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were 0 fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 0

TABLE 16.4.1. Details of sampling methods. 0

0 Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels; collars used where cattle/horses occur 0 Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth 0 burrow casts observed; agitated soil floated in water 0 Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer 0 substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 0 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn (late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated 0 with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may be absent. 0 Variety of sampling techniques Several techniques will always give a more robust picture of the fauna of a site, 0 because any weather- or site-affected bias in one technique will be compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is 0 regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is 0

28 0 Mill Lough

not regarded as sampling bias, buta genuine reflection of the habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites usingpitfall traps, especiallyas it is difficult to visit sites twice between spring tidesto place and lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which twowere sorted. There was only one site (Aughinish which has a spring/neapwater level variation of >1m) where flooding limited trap results to onlyone set.

Weather conditions and sampling The suction sampler is very efficient ingrass, rush and sedge swards which are dry, but useless if they are even slightly wet, because thesampling pipe and net becomes wet. The priority for sampling thereforewas to visit sites in response to dry weather forecasts, thus all sites were successfully sampledusing this technique. However,as a result of this strategy, the period that pitfalltraps were placed varied from site to site. This is not regarded as biasing resultsto any great extent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control. identification Voucher specimens of indicator species have beenretained and will be deposited in the National Museum of Ireland, and specimens ofmany of the other species have been retained in the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott,D.A., Merritt, R., Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irishwater beetle assemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sitesof international and national importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 14: 48-53. 7 1.J Methods used at this site

Carabidae and Staphylinidae (Coleoptera)were recorded from : (1) Juncus maritimus area- S-vac suction sampler (6 ix 1996), c. 2 m2; (2) Juncus maritimus area- 6 plastic pitfall traps with funnels and ethylene glycol preservative (6- 28 ix 1996); (3) Juncusgerardi area- 6 plastic pitfall traps with funnels and ethylene glycol 7I preservative (6- 28 ix 1996); U (4) Cobble search (n=30) from inlet shore (6 ix 1996).

Species were selectedas indicators of conservation value if : (1) they havea restricted habitat preference to a specific type of microhabitatassociated with the lagoon margins; and (2) they

29 u

Mill Lough 0 are reported in the literature as being local or rare,from which it is assumed that they are less 0 likely to survive in historically degraded ecosystems.

16.4.3 Survey Results 0

Only a single species of carabid and five species ofstaphylinid were recorded, none of which are regarded as indicator species (Table 16.4.2). 0

The staphylinid assemblage recorded from the Juncus maritimus area hadvery low numbers of species and individuals (Table 16.4.2). The species that were recordedwere grassland and 0 marsh species (Table 16.4.3). 0

0 TABLE 16.4.2. Carabidae and Staphylinidae (Coleoptera) recorded from Mill Lough. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989). 0

No. individuals Species 0

Carabidae

Pterostichus niger (Schall.) 13 0

Staphylinidae 0 Atheta melanocera (Thoms.) 1 Lathrobium brunnipes (F.) 1 Ocypus olens (Mull.) 3 0 Philonthus politus (L.) 1 Stenus nitidiusculus Steph. 1 0

0 TABLE 16.4.3. Staphylinid assemblage from Juncus maritimus area, Mill Lough (suction sample and pitfall traps combined). 0

Species No. Main biotope 0

Atheta melanocera (Thoms.) 1 Ripicolous, marshes Philonthus politus (L.) I Woodland, riparian Stenus nitidiusculus Steph. 1 Ripicolous, peatland, grassland

0

a

30 0 Mill Lough

16.4.4 Evaluation

Of no recorded conservation interest forterrestrial ecotonal community. (Rating categories : None, low,average, exceptional]

Scientific Argument for Rating

The very low numbers of individuals andspecies (Table 1) indicatesa large amount of disturbance by the apparent regular flooding(and probably drying between thespring tide periods). The few eurytopic non-halophilousripicolous species (Table 2) probablyfind the sampled areas too disturbed by flooding,but there is insufficient marine influenceto encourage salt-marsh species. The size of theuneroded shore areas containing margin vegetationis also probably too small to provide sufficienttotal area of suitable habitat.

J References

Lohse, G.A. and Lucht, W.H. (1989)Die Kdfer Mitteleuropas. 12. 1. Supplementbandmit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die KdferMitteleuropas.Katalog. Goecke & Evers, Krefeld.

J

J

31 Mill Lough

16.5 SUMMARY AND EVALUATION

Mill Lough is a small (5 ha) natural saline lakewith a natural tidal inlet.

The lake does not lie in or near a proposedNHA.

The following table shows the conservation value of the lake J based on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion

Geomorphology Moderate Aquatic Fauna Moderate Vegetation Potentially High Ecotonal Coleoptera None J

Geomorphology.

Mill Lough is a good example of a saline lakein peatland with a tidal inlet, but it is smaller than L. Aconeera with less rock anda greater tidal exchange. The salinity varies more widely, both temporally and spatially. Water floods extensiveareas of the shoreline at spring tides.

It can be classified as a peat lake with awide "barrier" composed of peat and rock.This type is not common in Europe butmay correspond to the "obs" of northern Scotland.

Mill Lough is rated as of moderate conservation valueas a good example of a natural saline lake with tidal inlet in rocky peatland.

Aquatic Fauna

Among 30 taxa recorded 28 were identified to species andfour were lagoonal specialists. The greatest number of specieswas recorded near the sea inlet. One limnic species, a beetle, was recorded from near the freshwater inlet.

The aquatic fauna was typical of a lagoon witha significant tidal inflow and a medium to high salinity. The component of marine species was thereforegreater than in L. Aconeera. Sedentary marine species such as tunicates and bryozoanswere occasional near the sea inlet. Localised areas of low salinity allowsome oligohaline species to survive e.g. near a stream inlet where one beetle specieswas taken.

No rare or interesting species was recorded.

Based on aquatic fauna, the lake is ratedas of moderate conservation value.

32 u

Mill Lough 0 Vegetation 0 Ruppia cirrhosa occurs around the whole site but was notfound in dense beds. Some Zostera fragments were found washed up on the shorein places. Fucoid algae were common in the tidal inlet and one species occurringfrequently along the rocky 0 shores of both the east and west to within approximately100 metres of the main freshwater inflow. 0 Marginal vegetation was more or less uniform. Juncus maritimus salttolerant community was dominant between stretches of bedrock shore. Small openPhragmites swamps occurred in sheltered areas of the north and southeast.

Mill Lough would seem to be a species-poor site withno particularly notable aquatic species. However, a survey of the deeper regions could wellyield more interesting 0 results and the site is therefore rated as "potentially valuable".

Full aquatic survey is recommended. 0

Ecotonal Coleoptera 0 Only a single species of carabid and five species ofstaphylinid were recorded, none of which are regarded as indicator species. 0 The staphylinid assemblage recorded from the Juncus maritimus area hadvery low numbers of species and individuals which indicates a large amount of disturbance by 0 the apparent regular flooding (and probably drying between the springtide periods). Areas of marginal vegetation may be too small, and thereis insufficient marine influence to encourage salt-marsh species. The species that were recordedwere 0 grassland and marsh species. The site is therefore rated asof no conservation interest for ecotonal Coleoptera. 0 Summary

Mill Lough is a natural tidal lake in peatland witha natural tidal inlet. It is similar to L. 0 Aconeera but smaller and more saline. There is some evidenceof pollution from domestic and agricultural sources but the effects do not appearto be severe and are probably limited by tidal flushing. 0

The aquatic fauna and vegetation were typical of a lagoonwith a significant tidal inflow and a medium to high salinity but little of special interest was recorded. 0

The vegetation appeared to be species poor but deeper areaswere not sampled. 0 Ecotonal Coleoptera were poorly represented and no indicator species wererecorded. 0 Overall, the lake is rated as of moderate conservation valueas a good example of a small, natural saline lake with typical fauna and vegetation but ofless value than L. Aconeera. Proposal as an SAC is recommended. 0

0 33 J

COASTAL LAGOONS IN THE REPUBLIC OF IRELAND J

7 (VOLUME 111) Li

17. CORRAGAUN LOUGH

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

7 Li

Prepared for the National Parks and Wildlife Service 7 LJ (BioMar/Life) J n j

17. CORRAGAUN LOUGH

CONTENTS

17.1 Study Area

17.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

17.2.1 Methods 17.2.2 Results 17.2.3 Discussion 17.2.4 Threats 17.2.5 Evaluation 17.2.6 References

17.3 Vegetation Survey (Pat Hatch)

17.3.1 Site Description 17.3.2 Methods 17.3.3 Results Shore based survey Transect tables 17.3.4 Evaluation

17.4 Ecotonal Coleoptera (Jervis Good)

17.4.1 Site description 17.4.2 Methods 17.4.3 Results 17.4.4 Evaluation 17.4.5 References

17.5 Summary and Evaluation

U

J

J Corragaun Lough J

17. CORRAGAUN LOUGH, Co. Mayo.

OS Grid Reference: L 748 698, 1:50,000 Sheet No. 37 Alternative names:

17.1 STUDY AREA

General features Corragaun Lough is situated on the west Mayo coast, 5km north of Killary Harbour and 7 km from Killadoon (Fig. 17.1.1). The lake liesat the head of a long, shallow tidal inlet impounded by the formation of a dune barrier.The dunes are transgressive J and the lake has been considerably reduced in size sincethe early maps were drawn due to infilling of the lake and the onshore movementof the dunes. The bed of the lake is sand, with silt and peat at the eastern landwardend where a reedbed of Phragmites has formed. A freshwater stream enters the lake at theeastern end which drains from high land to the east. Part of the area at present occupied by the lakemay have been cut for peat. Some areas in the surrounding land have been cut in thepast and are still cut at present on a small scale. Praeger (1934) described the area as "utterly windswept" but "wouldwell repay further study". A report for the Commission for InternationalNature Protection describes the area as unique for Europe and Eireas a landscape, geologically, geomorphologically and botanically (Westermann & Westhoff, 1974). The National Coastline study regarded Corragaun withinan exceptional landscape, warranting declaration as a "National Park" or similar (see RoonahLough, 2.18). Instability of the dunes and exposure to strong winds fromthe Atlantic cause the landforms of the area to be highly dynamic. Bekkers etal. (1976) state that the Ordnance survey map of 1839 differs strikingly from that of1919, the latter showing lakes and dunes previously non-existent. Corragaun also changed shape between1919 and 1976 (Bekkers et al. 1976) and according to localinformation has been reduced in size considerably over the last 20 years.

The lake is part of the large proposed NHA whichincludes the Mweelrea Mountains J (Site Code No. 1932).

J Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. J The mean daily air temperature is6°C in January and 14.5-15.0 °C in July. The growing season (the period of mean daily air temperatures above6 °C) is 8.5 months and as snow and frosts are rare, some plant growthis possible in winter months. Li Annual rainfall is approximately 2000 mm, and the number ofrain days (1 mm or

1 0

0

0

0

0

0

tJ

tJ

IJ

Gn.eyard IJ

Corragaun Lough, 0

0

0

1 Car.ct.e 0

(C.rkns

Fig. 17.1.1Section of l :50 000 map showing locality of CorragaunLough

D

0 J Corragaun Lough

more) is approximately 200. Winds are mainly from the southwest.Mean annual hourly wind speeds are between 6 and 7 m/s anda maximum wind speed of 50 m/s is estimated to occur once in 50 years. The daily durationof bright sunshine averages J 3.5-4.0 hours. Mean relative humidity is around 85% as onall Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 m and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 m (Carter 1992).Maximum wave heights (averaging once in 50 years) are 30-35 m(Couper 1983). Tides are semi- diurnal and sea temperatures are lowest in February and highestin August. Landscape and Geology Bedrock is , mica-schist, gneiss and quartzite. Soils other than peat are mostly peaty gleys. Inland thesteep slopes with shallow soils are of extremely limited land use capability (Royal Irish Academy,1979). Land surrounding the lough consists of small irregular fields of semi-improvedpasture, bare rock, peatbogs and wet heathland with machair, saltmarsh and sand-dunesalong the coast..

Lake Topography The lagoon at present is approximately 400 m from northwest to southeast, 200 m across and covers about 7 ha.Water depth is 20-70 cm over most of the lake with slightly deeper water in the mainchannel draining from the lake. The n bed of the lake is mostly composed of sand withmore silt and unconsolidated peat at J the eastern end where the river enters. The lake isbordered by rock in several places and by low cliffs of peat along the northern shoreline.Sandbanks have formed at the outlet to the lake.

Hydrology A small river enters the lake in the southeast andundoubtedly freshwater also enters through the slow release of groundwater fromthe saturated peat higher in the valley and also in direct rainfall. Seawaterappears to enter on most tides, through a long sinuous channel. A tidal variation in waterlevel is noticeable in the J outlet channel but is less noticeable in the main bodyof the lake. Salinity and water quality Despite the fact that seawater appears to enter on every tide the lake is also likely to receive large volumesof freshwater runoff from the surrounding land. Salinity levels may vary considerably, both spatially andtemporally, depending on precipitation and tides. The peaty soils of thesurrounding land would affect the delivery time of both surface- and ground-water flowsto the lake through absorption and slow release of water. The prolonged flow offreshwater to the lake during the "dry" months may result in lower salinities thanmight be expected. On the J other hand, winter storms may result in a higher volumeof seawater entering the lake and raising salinity levels at a time when they mightbe expected to fall.

J Stratification is not likely to occur at any period ofthe year due to the shallow nature of the lake and regular flushing.

The surrounding land is relatively natural and even grazing landis likely to receive only limitedfertilizerapplications.However,adeeplayerof organicsilt and J unconsolidated peat has accumulated in the area where the riverenters and this may indicate erosion higher in the catchment. J

2 Corragaun Lough

17.2 AQUATIC FAUNA

J Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin 17.2.1 Methods

Environmental variables Water depths were measured from an inflatable dinghy. J The position of each sample area was determined using aGPS Personal Navigator ri (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that J positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the n centre of the site. u At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o rl precision). A photographic record was made of the site andlocal information sought J concerning the background and recent history. ri J Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for J one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations C and D inorder to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole (1994). The nets 11 used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16,12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination J All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult to make quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of J

3 Corragaun Lough EJ

the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution 0 within the water column. Abundance categories of present,common and abundant are purely subjective, and absolute numbers vary between taxa. 0 Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of these werelarval or juvenile stages and difficulttoidentify with certainty. Some groups require adult malesfor a identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (egJaera, hydrobiids). 0 17.2.1 Results

Corragaun Lough was sampled on 12.vi.96 during the first partof the survey, and 0 from 17-19.ix.96 during the more intensive survey. 0 Six sampling stations were selected in the lake to reflectthe influences of substrate, and freshwater/seawater inflows. Fig.17.2.1 shows the position of these sampling stations in the lagoon. 0

Environmental Variables 0 Station A (OS 7469 6982) was located in the baybetween the southern shoreline and the sandbank at the mouth of the outlet (Plate 17.2.2).Water depth varied from 0- 30 cm, substrate was sand and salinity measured 25%o in Septemberand 0- 1 %o in June. 0 Station B (OS 7465 7049) was located on the northside of the outlet channel in a bay surrounded by low peat cliffs on three sides and rockto the east. Substrate consisted of rock, solid peat and a mixture of fine sand,silt and unconsolidated peat. Water iJ depth varied from 0- 25 cm and salinity measured 32%0. Station C (OS 7499 6973) was located on the shoreof a rock outcrop in the central, 0 narrow part of the lake. Substrate was solid rock andsand. Water depth varied from 0 - 1 m in the channel running past the rockand salinity measured 32%0. Station D (OS 7523 6982) was located in the northwestcorner of the lake, among 0 Phragmites, in the main area of freshwater influence (Plate 17.2.4). Depthvaried from 0 - 25 cms, substrate was fine sand andsilt over peat and salinity measured 16- 25%0. 0 Station E (OS 7506 6963) was located in the southwestcorner near an area of recently cut Phragmites (Plate 17.2.2 & 4) Water depth variedfrom 0 - 25 cms, 0 substrate consisted of soft anoxic mud and peat and salinitymeasured 28%0. Station F (OS 7482 6965?) was located along the southernshoreline on a stony 0 beach. Substrate consisted of bedrock, stones of various sizes andpockets of fine silt and sand. Water depth varied from 0- 25 cms and salinity measured 32 %o.. 0 Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 17.2.1. Among 20 taxa listed, 17are identified to species. The list comprises 2 0 marine species, 4 poly-mesohaline, 10 euryhaline, and 1oligohaline species (Table

4 0 J

J

J 75 74 J

Fig. 17.2.1Location Map of Sampling Stations in Corragaun Lough, Co. Mayo. 0

Table 17.2.1. Fauna Recorded in Corragaun Lough, Co. Mayo. Juneand September, 1996. 0 ( ) = records from June. Fauna Sampling Stations ( L.T. = light-trap) 0 A B L.T.B C L.T.C D L.T.D E F L.T.F Porifera j Cnidaria _ 0 Turbellaria

Nemertea _ j Annelida Arenicola marina + 0 Crustacea Ostracoda Copepods 0 Cirripedia Mysidacea Neomysis integer a c 350 a 500 a 300 c o 150

Isopoda Eurydice pulchra 1 0 Jaera nordmanni + + Amphipoda Corophium volutator c o Gammarus duebeni + + 0 G. zaddachi + + + + + + + + Orchestia gammarella + 0 Tanaidacea j Decapoda Crangon crangon c c 3 c 5 o Carcinus maenas + + + + + + + Palaemon serratus o 0 0 Palaemonetes varians o Arachnids Insects iJ Thysanura Ephemeroptera a Odonata Plecoptera Trichoptera 0 Hemiptera Corixidae c 10 + + + Sigara stagnalis + + + + + Coleoptera (+) 0 Diptera Chironomidae ! + + + + Tipulidae o Molluscs 0 Prosobranchia Potamopyrgus antipodarum + + j + j

j Opisthobranchia t ! Pulmonata j a Bivalvia Mya arenaria shells shells Scrobicularia plana shells] shells! Bryozoa a

Echinodermata I T Tunicata -- -

1 Teleostei Anguilla anguilla + I 17,31 F, 1 + iJ Gasterosteus aculeatus + a 3 a 52 a 85 o a Mugilidae F, 4 F, I

Platichthysesus + ; + i F, 1 + + + 0

0 + = present; o = occasional; c = common; a= abundant; F = fyke net 0 Corragaun Lough

17.2.2). Two of the species are listed as a lagoonalspecialists in Britain (Davidson et J al. 1991). Species distribution can be correlated with both salinity and habitat.Marine or poly- 7 u mesohaline species were mostly present in the seaward sector ofthe lake (Arenicola, Eurydice, Palaemon serratus) while corixids were found in the midand landward sectors. The cryptic species Jaera nordmanni occurred only at Cand F where there were stones. n u Table 17.2.2 Ecological categories of the recorded taxa in Corragaun Lough (excluding marginal species). L = lagoonal specialist according to Davidsonet al. (1991)

Marine Eurydice pulchra Palaemon serratus

Poly-mesohaline Arenicola marina Corophium volutator Crangon crangon Mugilidae

Euryhaline Neomysis integer Jaera nordmanni J Gammarus duebeni Gammarus zaddachi Palaemonetes varians L Carcinus maenas Sigara stagnalis L Anguilla anguilla Gasterosteus aculeatus Platichthysflesus J Oligo-mesohaline Potamopyrgus antipodarum Limnic None J 17.2.3 Discussion

The fauna was rather poor in spite of open contactwith the sea and a gradient in species occurrence from the sea - inland. The explanation maybe the wide fluctuations in salinity which occur. On 16 June 1996, the salinitythroughout the lake was only 0- 1%o compared with 16-32%o during sampling in September. Variations ofthis magnitude, especially if changes are sudden, would not be toleratedby the more sensitive species. The presence of shells of Mya arenaria andScrobicularia plana, both estuarine species, suggests that conditions may have been differentin the past.

None of the species identified is of special interest orcan be described as rare in Ireland.

5 u

Corragaun Lough 0

17.2.4 Threats D The whole coastline in this area is highly dynamic. CorragaunLough has changed shape considerably in the past century and has, according tolocal information, been 0 notably reduced in size. The reduction is size is believedto be mainly attributable to the deposition of sand from the dunes and beach. Additionally,the sediment and nutrient loading of the river may have increased. 0 Farming in the catchment area. could be contributing higher levelsof nutrients to the system, especially by way of the small river. This issuggested by the large amount of Cladophora in the lake. EI Phragmites appears to have been cut in one area. 0 17.2.5 Evaluation 0 Corragaun Lough is a completely natural sedimentary lagoon with anatural tidal inlet and is therefore a site of international importance basedon geomorphology alone. It lies in an area of coastline subject to dynamicchanges in sedimentation patterns. It is 0 one of a number of lagoons, and "former lagoons" onthe south Mayo coast which vary in their geomorphology and degree of marine influence. Someare entirely fresh, others saline, while barriers may be of sand or cobbles,or both. Corragaun Lough is 0 the only one of this series with a permanent tidalinlet through which the sea enters at each high tide. 0 The post-glacial history of parts of this coastline has beenstudied in detail and continues to be of great interest to geomorphologists. 0 The coastal lagoons of this area are of botanical andornithological value. Corragaun Lough undergoes wide fluctuations in salinity which limit faunaldiversity. Relatively few species of aquatic fauna were present and nonewas interesting or rare. 0 The lake is part of a proposed NHA (Site CodeNo. 1932). The lake has little conservation on its own on thebasis of aquatic fauna but as one of a 0 series it sheds light on the history and geomorphological processesof this section of the coastline. It is recommended that the complete series oflakes, from L. Polimore in the north to L. Doovilra in the south be designatedas a proposed SAC. 0

17.2.6 References and Additional Sources of Information 0

Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department 0 Anonymous. 1974. The Scientific Interest of the Area knownas Dooaghtry, Co. Mayo. Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation 0 appraisal. Biological Conservation 49, 295-313. Bekkers, A., Brock, Th. & J. Klerkx. 1976. A VegetationStudy of Some Parts of Dooaghtry, Co. Mayo., Republic of Ireland. Unpubl. report. Laboratory of Geobotany, Catholic University of Nijmegen, Holland. 76 pp. 0

6 0 J Corragaun Lough

Cabot, D. 1966. Cephalanthera longifolia in West Mayo. Irish Naturalist'sJournal 15: 156 Cabot, D. 1969. Spiranthes spiralis in West Mayo. Irish Naturalist'sJournal 16: 177 Cabot, D. & Ruttledge, R.F. 1967. Liquid Assets' List ofWildfowl Wetlands in the J Republic of Ireland of National and International Importance. Irish Wildbird Conservancy, Pub. No. 5. Dublin. Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. J Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Decoy, R., Delaney, C., Carter, R.W.G. and Jennings, S.C. 1996.Coastal stratigraphies as indicators of environmental changes upon European coasts in the late Holocene. Journal of Coastal research 12: 564-588. Delaney, C. and Devoy R. 1995. Evidence from sites inwestern Ireland of late J Holocene changes in coastal environments. Marine Geology 124: 273- 287. 7 Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. IJ Goodbody, Q. 1977. Solid Geology of Uggool and Dooaghtry (unpubl.map). Haughton, J.P. 1957. Physiography and Climate. In: Meenan, J. &D.A. Webb.(eds.) A View of Ireland Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine J crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. J Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. J Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. Praeger, R.L. 1934. The Botanist in Ireland. Reprinted in 1974by E.P. Publishing Ltd., Dublin. 398 pp. Praeger, R.L. 1937. The Way That I Went. Hodges, Figgis& Co. Dublin. 174 pp. Royal Irish Academy. 1979. Atlas of Ireland. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp.. Westermann, J.H. & V. Westhoff. 1974. Report on the DooaghtryArea. Publication of the Netherlands Commission for International Nature Protection, Amsterdam. 5 pp.

7 0

10

Plate 17.2.3View of northern shoreline of Corragaun Lough showing low peatcliffs and stranded mats of

Plate 2.174 View of the eastern area of Corragaun Lough,Stations D (left) and E (right) so 44 n

r

Plate 1 7.2.1 View of Corragaun Lough looking west towardthe dune system.

Plate 17.22 View of Corragaun Lough, looking east to theMweelrea Mountains. Station A on the right, E in the distance.

Is J

Corragaun Lough

17.3 VEGETATION SURVEY J Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

7 J 17.3.1 Site Description(Fig. 17.3. 1) This fairly small, sandy lagoon lies in a narrow valleyof heath, grassland and frequent rock outcrops. Grazed Nardus stricta grassland borders the site tothe north and east, wet Molinia caerulea grassland, flushes and heathy outcrops to thesouth and saltmarsh on low-lying sandy ground to the west. A narrow bandof hazel scrub runs across part of the southern slopes.

Most of the shore is either low peat cliff orexposed bedrock with marginal areas typically narrow. Swamp vegetation occurs at the eastern end ofthe lough, where it is associated with the main freshwater inflow and at one partof the north central shore where a smaller inflow emerges.

The saltmarsh at the western end also borders the outletto the sea, which joins the lough here.

17.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects

The locality of these is shown in Fig. 17.3.2.

J Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

8 u

0

0

Key 0 aooc. - Exposed bedrock X64 - I,ow pedt c(i f / 0 0 -Swa-P -5alfmarsh 0

PomiYldrif species codes ausfrali 5 0 Pdus- 5 mar S,;rPas marit-l'U5 5 5 5p SIaG _ 0 ifmcll- Tunat5 marif i-l"5 PWlar- Puccinelli d wla Crmar_ IauX r- Pa( Cleockaris p4[u5fri5

0

0

0

0

Fig. 17.3.1or>'uaaun kotankCo Mdyo- ilea a

0 J

7 N J 7ofh e sea J `rA-7E :Travtsccf s A--r : Poinf5 of change in aquafic /marVina( vTfc(hoh

J

Location of Transectsand Fig. 17.3.2 Corragaun Lough,Co.Mayo:Shore-based Survey Sections Corragaun Lough

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substratewas also recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites.

In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadratsor releves. Sample area was generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the transect.

Representative examples of every marginal community encountered during thecourse of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentagecover (using the Domin scale) and the calculation of frequency for each species:

Cover/Abundance Values Each species in a sample is given a percentagecover value according to the Domin scale as follows:

Domin. 10 91-100% 9 76-90 % 8 51-75 % 7 34-50 % 6 26-33 % 5 11-25 % 4 4-10 % 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals

9 J

Corragaun Lough

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100 % IV 61-80 % III 41-60 % 11 21-40 % 7 I LJ 1-20 % rl Note: The NVC volume covering saltmarsh communities was not availableat the time J of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume. U Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report. n Each aquatic and marginal transect sample is presented here intable form, with a brief u description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of lJ variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course. M J Adjacent habitat and land use was described in general termsand dominant species recorded. 7 v 2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal J communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in rl floristics, substrate and/or adjacent habitat. These points of change aremarked on the J site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where J water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

I LJ Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences:

10 u

Corragaun Lough 0 a). The five largest lagoons were surveyed using transects onlyas there was 0 insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0

Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in themain, to the lagoon shores.

Identifications 0

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University 0 College Galway and Michael Guiry, Professor of Botany, University CollegeGalway

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of 0 charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as 0 `Valuable', `Potentially Valuable' and `Not Valuable'.

A 'Valuable ' site is one that is shown tobe of particular interest and that is considered 0 to be worthy of conservation/protection.

0

11 J

Corragaun Lough rl

I LJ A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable'site is one that is shown to beof little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

17.3.3 Results

1 Shore-based survey

Section A-B

Aquatic: Enteromorpha only- sparse n Sand substrate u Marginal:Exposed bedrock with crustose lichens Occasional peat cliff- average height 40cm - with Juncus maritimus

7I patches LA Adjacent:Nardus stricta grassland- grazed

Section B-C (Transect B)

M Aquatic: Ruppia c.f maritima- low growing - patchy cover LJ Enteromorpha- free floating - sparse Filamentous algae- free floating - sparse rl J Marginal:Peat cliff - average height 1 m

Adjacent:Juncus maritimus - Festuca rubra- Agrostis stolonifera community with salt tolerant species. 30-40m Backing Nardus stricta grassland as A-B J

Section C-D

Aquatic: 71 Unchanged J Marginal:Peat cliff - average height 50cm

Adjacent:Nardus stricta grassland as A-B

12 u

Corragaun Lough 0

Section D-E 0

Aquatic: Unchanged 0 Marginal:Schoenoplectus lacustris ssp tabernaemontani swamp with occasional Scirpus maritimus and Phragmites shoots. 15m Backing Puccinellia maritima dominated saltmarsh to c.30m 0

Adjacent:Unchanged 0

0 Section E-F

Aquatic: Unchanged 0

Marginal:Exposed bedrock with crustose lichens 0 Adjacent:Unchanged 0

Section F-G 0 Aquatic: Unchanged

Marginal:Scirpus maritimus swamp with occasional Schoenoplectus lacustris ssp 0 tabernaemontani and Phragmites shoots. c.20m Backing peat cliff- average height 50cm 0 Adjacent:Backing Juncus maritimus- Festuca rubra - Agrostis stolonifera community on 0 promontory Grading to Nardus stricta grassland as before 0

Section G-H 0

Aquatic: Unchanged 0 Marginal:Peat cliff - average height I m

Adjacent:Backing Juncus maritimus community as before 0 Grading to Nardus stricta grassland as before 0

0

13 Corragaun Lough J

J Section H-I

J Aquatic: Unchanged

Marginal:Exposed bedrock with crustose lichens

Adjacent:Calluna vulgaris - Erica cinerea dominated heath on rocky outcrop 7 Backing Juncus maritimus community as before LJ Grading to Nardus stricta grassland as before

Section I-J

Aquatic: Unchanged

Marginal:Peat cliff - average height 50cm

Adjacent:Juncus maritimus community as before Grading to Nardus stricta grassland as before

Section J-K (Transect C)

Aquatic: Unchanged

Marginal:Swamp vegetation with Scirpus maritimus and Schoenoplectus lacustris ssp tabernaemontani each locally dominant with occasional Phragmites 7 shoots. c.30m J Backing peat cliff- average height 40cm 7 J Adjacent:Unchanged Section K-L (Transect D)

Aquatic: Unchanged

Marginal:Phragmites australis single species swamp. c.50m Grading to Scirpus maritimus dominated swamp with frequent Phragmites. C. I OOm Grading to Schoenoplectus lacustris ssp tabernaemontani swamp with frequent Scirpus maritimus and Phragmites. c.20m

Adjacent:Molinia caerulea dominated flush vegetation with frequent Myrica gale, Potentilla erecta, Ranunculus acris. Grading to Nardus stricta grassland as before

J

14 u

Corragaun Lough 0

a Section L-M

Aquatic: Unchanged 0 Marginal:Phragmites australis single species swamp. c.30m 0 Adjacent:Agrostis stolonifera - Festuca rubra - Plantago coronopus grassland Grading to Nardus stricta grassland as before a

Section M-N

Aquatic: Enteromorpha Filamentous algae

Marginal:Juncus maritimus community as before. c.20m 0 Adjacent:Nardus stricta grassland as before 0

Section N-O 0 Aquatic: Unchanged

Marginal: Swamp with Scirpus maritimus and Schoenoplectus lacustris ssp tabernaemontani each locally dominant. 5-20m 0

Adjacent:Unchanged 0

Section O-P 0

Aquatic: Unchanged a Marginal:Peat cliff c.70cm

Adjacent:Juncus maritimus community. 1-2m 0 Grading to flush vegetation dominated by Molinia caerulea with frequent Myrica gale, Schoenus nigricans, Potentilla erecta, Succissa pratensis, 0 Narthecium ossifragum

0

15 J

Corragaun Lough

Section P-Q

Aquatic: Ruppia c.f. maritima 7 Enteromorpha J Filamentous algae

Marginal:Exposed bedrock with crustose lichens

Adjacent:Flush vegetation as O-P with occasional patches of Calluna vulgaris dominated heath on drier ground. 30-50m Backing Corylus avellana scrub. c.50m

I Section Q-R (Transect E)

Aquatic: Unchanged

Marginal:Open Eleocharis palustris dominated community with salt tolerant species on stony shore. 4m

Adjacent:Unchanged

Section R-S

As P-Q

Section S-T (Transect A)

Aquatic: Unchanged

Marginal:Saltmarsh dominated by Puccinellia maritima and Glaux maritima. c.500m

Adjacent:Ammophila arenaria dune grassland (barrier)

J ri J

16 u

Corragaun Lough 0

2. Transects 0 Site. Corra aun Lough Transect code: A

Location: Saltmarsh bordering outlet to sea Sample point: 1 Aquatic - 150m out Sample area: 25m2 5x5 Substrate: Sand 0

Depth: 40 cm Salinit : 2arts per thousand

NVC communit : ----- 0 Height cm Cover Total Plant 50 Hi her Plant 40 a

Ruis c.f maritima 6 40 a Algae 10 0 Enteromo ha 10

0 Description: Low growing Ruis dominant with frequent free-floating Enteromoha. Same species at more or less constant cover from 60m- 150m out. 0

0

Site: Corra aun Lough Transect code: A Location: Saltmarsh bordering outlet tosea Sample point: 2 Aquatic- 50m out 0 Sample area: 25m2 5x5 Substrate: Sand

Depth: 20 cm Salinit : 2arts per thousand NVC communit : Height cm Cover Total Plant 50 0 Higher Plant 5

Ruis c.f maritima 6 5 0

Algae 45 0 Enteromor ha 45 0 Description. Enteromor ha dominant. Low growing Ruis now sparse. More or less unchanging 40m- 60m out. 0

0

0 17 0 J

Corragaun Lough

Site: Corra aun Lough Transect code: A Location: Saltmarsh bordering outlet to sea Sample point: 3 Aquatic - 25m out rl J Sample area: 25m2 5x5 Substrate: Sand Depth: 10 cm Salinit : 2arts per thousand

NVC communit : ----- Height cm Cover Total Plant 90

Enteromo ha 90

Description: Dense cover of free-floating Enteromor ha. More or lesssame cover 0 - 40m out.

Site: Corra aun Lough Transect code: A Location: Saltmarsh bordering outlet to sea Sample point: 4 Marginal Sample area: 100m2 10x10 Substrate: Sand

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 20

Puccinellia maritima 3 10 Glaux maritima 3 10

Descri tion: Open patchy cover of Puccinellia and Glaux onsandflat. c.100m

7 J

is u

Corragaun Lough 0

Site: Corra aun Lough Transect code: A 0 Location: Saltmarsh bordering outlet to sea Sample point: 5 Marginal Sample area: 100m2 10x10 Substrate: Sand

Depth: 0 cm Salinit : ----- 0 NVC communit :Undetermined Height cm Cover Total Plant 50 0

Puccinellia maritima 3 20 0 Glaux maritima 4 20 A rostis stolonifera 6 5 Planta o corono us 4 5 0 Planta o maritima 5 < 1 0 Description: Puccinellia- Glaux dominated sp ecies-poor saltmarsh vegetation. c.400m.

Cover increasing to landward. Grading to Ammo hila arenaria dune . grasslandbarrier 0

0 Site: Corra aun Lough Transect code: B Location: Peat cliff shore Sample point:1 Aquatic - 20m out Sample area: 16m2 4x4 Substrate: Sand and silt 0 Depth: 20 cm Salinit : 4arts per thousand NVC communit :----- Height cm Cover 0 Total Plant 50 Hi her Plant 40 0 Ruis c.f maritima 6 40 0 Algae 10

Enteromor ha 10 a

Description: Low growing Ruis dominant. Some plants in flower and fruit. Enteromor ha 0 free-floating only. 0

0

0

19 J

Corragaun Lough

Site: Corra aun Lough Transect code: B Location: Peat cliff shore Sample p oint: 2 Aquatic - 5m out J Sample area: 16m2 4x4 Substrate: Sand, cobbles Depth: 20 cm Salinit : 4arts per thousand

NVC communit : ----- Hei ght cm Cover Total Plant 95

Filamentous algae 70 Enteromo ha 15 30

Substrate

Sand 90 Cobbles 10

Description: Filamentous al gae dominant with Enteromo ha confined toscattered cobbles. No hi herlant s ecies. Backing 60cm eat cliff.

M U Site: Corra aun Lough Transect code: B Location: Peat cliff shore Sample point: 3 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: ----- Salinit : ----- NVC communit :Undetermined J Height cm Cover Total Plant 100

Juncus maritimus 70 - 90 Festuca rubra 30 50 A rostis stolonifera 30 40 Leontodon autumnalis 15 5 Glaux maritima 10 < 1 J Cochlearia an lica 4 < 1

Description: Dense cover of Juncus maritimus tussocks with A rostisstolonifera and Festuca rubra co-dominant inspecies-poor salt-tolerant community. 40m. Grading to Nardus stricta grassland with frequent rock outcro ps.Grazed.

20 u

Corragaun Lough 0

Site: Corra aun Lough Transect code: C 0

Location: Marginal swam Sampleoint: 1 Aquatic - lm out -grapnel Sample area: Grapnel only Substrate: Peatsilt 0 Depth: 40 cm Salinit : 0arts per thousand

NVC communit : ----- Height cm Cover 0

Ruis c.f maritima Enteromor ha a Filamentous algae 0 Description: 0

0

D

Site: Corra aun Lough Transect code: C Location: Mar inak swam Sample point: 2 Marginal 0 Sample area: 100m2 10x10 Substrate: Peatsilt

Depth: 30 - 40 cm Salinit : 0arts per thousand G NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - S.lacustrisssp tabemaemontani sub-community Height cm Cover D Total Plant 65

Schoeno lectus lacustris sstabernaemontani 100 60 0 Phra mites australis 80 5 0 Description: Open Schoeno lectus lacustris swam with sparse Phra mitesshoots. 10m.

0

0

0

21 0 J rl Corragaun Lough U

Site: Corra aun Lough Transect code: C Location: Marginal swam Sample point: 3 Marginal J Sample area: 100m2 10x10 Substrate: Peatsilt Depth: 10 - 30 cm Salinit : 0arts per thousand NVC communit :S21 Scir us maritimus swam - Scius mafitimus sub-community Height cm Cover Total Plant 100

Scius maritimus 70 100 Phra mites australis 80 < 1 9 J Description: Dense Scius maritimus swam with sparse Phra mites shoots. 16m. Backing 40cm eat cliff.

7

Site: Corra aun Lough Transect code: C Location: Marginal swamps Sample oint: 4 Marginal Sample area: 16m2 4x4 Substrate: Peat

Depth: ----- Salinit : ----- J NVC communit :Undetermined Height cm Cover Total Plant 100

Juncus maritimus 120 75 Festuca rubra 30 50 A rostis stolonifera 30 30 Leontodon autumnalis 20 < 5 Glaux maritima 15 < 5 Cochlearia an lica 6 < 1 Tri lochin maritima 15 < 1 Samolus valerandi 15 < 1 Planta o lanceolata 15 < 1 J H drocot le vul aris 3 < 1

Description: Tall, fairly dense cover of Juncus maritimus with Festucarubra and A rostis stolonifera co-dominant. 70m. Grading to Nardus stricta grassland with frequent rock outcrops. Grazed.

J

22 a

Corragaun Lough a

Site: Corra aun Lough Transect code: D 0 Location: Freshwater inflow Sample point: 1 Aquatic - 1 m out- grapnel Sample area: Grapnel only Substrate: Peatsilt 0 Depth: 60 cm Salinit : 0arts per thousand NVC communit :----- Height cm Cover 0

Ruis c.f maritima Enteromor ha 0 Filamentous algae a Description'. 0

0

Site: Corra aun Lough Transect code: D Location: Freshwater inflow Sample point: 2 Marginal 0 Sample area: 100m2 10x10 Substrate: Silt

Depth: 50 cm Salinit : 0arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community 0 Height cm Cover Total Plant 70 0

Phra mites australis 180 70 0

Description: Fairly dense single species Phra mites swamp. 60m. a

0

a

0

a

0

23 J

Corragaun Lough

Site: Corra aun Lough Transect code: D Location: Freshwater inflow Sample oint: 3 Marginal Sample area: 100m2 10x10 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :S21 Scius maritimus swam - A rostis stolonifera sub-community Height cm Cover (%) Total Plant 95

J Scius maritimus 70 75 Phra mites australis 100 20 A rostis stolonifera 30 40 J Festuca rubra 30 25 Cochlearia an lica 10 < 5 Leontodon autumnalis 20 < 1 Glaux maritima 15 < 1 Samolus valerandi 15 < 1 7 Bare eat 10

Description: Scir us maritimus dominant amongst open, low growing Phramites cover with open round cover of salt tolerant species dominated b Arostis stolonifera and Festuca J rubra. 30m.

Site: Corra aun Lough Transect code: D Location: Freshwater inflow Sample point: 4 Marginal Sample area: 100m2 10x10 Substrate: Silt

Depth: 15 cm Salinit : 0arts per thousand NVC communit :S21 Scius maritimus swam - A rostis stolonifera sub-community Height cm Cover %) Total Plant 95 n J Scius maritimus 80 90 Phra mites australis 100 5 A rostis stolonifera 30 < 1

Description: Fairly dense Scir us maritimus swam with low growing,sparse Phra mites cover. 80m.

24 u

Corragaun Lough 0

0 Site: Corra aun Lough Transect code: D Location: Freshwater inflow Sample point: 5 Marginal Sample area: 100m2 10x10 Substrate: Silt 0 Depth: 10 cm Salinit : 0arts per thousand NVC community: S20 Shoenoplectus lacustris ssp tabernaemontani swamp- Agrostis stolonifera sub-comunit 0 Height cm Cover Total Plant 95 G Schoeno lectus lacustris sstabernaemontani 100 50 Scius maritimus 50 10 a Phra mites australis 80 5 A rostis stolonifera 30 60 Glaux maritima 15 < 1 0

Description: Open low growing swam vegetation with Schoeno lectus dominantamongst 0 the tall emer ents and A rostis stolonifera forming afairly open mat below. 20m. 0

0 Site: Corra aun Lough Transect code: D Location: Freshwater inflow Sample point: 6 Marginal Sample area: 100m2 10x10 Substrate: Peat 0 Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover (% 0 Total Plant 100

Molinia caerulea 100 90 M ricaale 40 5 Potentilla erecta 15 < 5 0 Ranunculus acris 15 < 5 Irissuedacorus 130 < 1 Angelica s lvestris 100 < 1 Fili endula ulmaria 40 < 1 Mentha a uatica 30 < 1 Galium alustre 15 < 1 c

0 Description: Dense cover of Molinia tussocks with sparse freshwater flushvegetation. c. 100m Grading to Nardus stricta grassland with frequent rock outcrops. Grazed. 0

0

25 J

Corragaun Lough

Site: Corra aun Lough Transect code: E Location: Open shore Sample point:1 Aquatic - 70m out- grapnel Sample area: Grapnel only Substrate: Silt and sand

Depth: 40 cm + Salinit : 4arts per thousand

NVC communit : ----- Height cm Cover %)

Ruis c.f maritima Enteromor ha

J Description:

Site: Corra aun Lough Transect code: E Location: Open shore Sample point: 2 Aquatic - 50m out Sample area: 16m2 4x4 Substrate: Silt and sand

Depth: 30 cm Salinit : 2arts per thousand NVC communit :----- Height cm Cover Total Plant 95 J Enteromo ha 95 r-, U Description: Dense cover of Enteromor ha only. Same species atmore or less same cover 20 - 70m out.

J

26 a

Corragaun Lough c

0

Site: Corra aun Lough Transect code: E Location: Open shore Sample point: 3 Aquatic- 15m out 0 Sample area: 16m2 4x4 Substrate: Silt and sand Depth: 30 cm Salinit : 2arts per thousand 0 NVC communit :----- Height cm Cover Total Plant 40 0 Higher Plant 20

Ruis c.f maritima 6 20 a

Algae 20 0 Enteromo ha 20 20 a

Description: Low -growing Ruis co-dominant with Enteromoha. Same sp ecies at more 0 or less same cover 8 - 20m out. 0

0

D Site: Corra aun Lough Transect code: E Location: Open shore Sample point: 4 Aquatic - 5m out Sample area: 16m2 4x4 Substrate:Silt and sand 0

Depth: 0 - 15 cm Salinit : 2arts per thousand NVC communit :----- Height cm Cover Total Plant 100

Enteromo ha 15 100

0 Description: Dense Enteromor ha only. 0- 8m out.

0

0

0 27 J

Corragaun Lough

J Site: Corra aun Lough Transect code: E Location: Open shore Sample point: 5 Marginal J Sample area: 16m2 4x4 Substrate: Gravel, cobbles, boulders Depth: 0 cm Salinit : ----- NVC communit :S 19 Eleocharisalustris swam - A rostis stolonifera sub-community Height cm Cover Total Plant 20

Eleocharisalustris 20 5 Puccinellia maritima 10 5 A rostis stolonifera 10 5 Glaux maritima 8 5 S erlaria marina 5 < 1 Tri lochinalustris 8 < 1 Planta o corono us 5 < 1 Planta o maritimus 8 < 1 Cochlearia an lica 6 < 1 Isole es cernua 6 < 1

J Bare substrate 80 n j Gravel 70 Cobbles 10 Boulders < 1

Description: Sparse shore community dominated b Eleocharis, Puccinellia and Arostis stolonifera. 4m. 1 Backing 45 degree slope with wet heath vegetation dominated bSchoenus ni ricans, Molinia caerulea, Calluna vul aris, Potentilla erecta withErica tetralix, Succisa ratensis, Narthecium ossifram, M ricaale.

J

J n J

28 0

Corragaun Lough 0

17.3.4 Evaluation 0

`Potentially Valuable' 0

This is a small sandy lagoon of low salinity (0-4parts per thousand) at time of survey. 0 Ruppia c.f. maritima was the only aquatic macrophyte recorded duringthis survey. It has a wide distribution around the site at sparse topatchy cover and is low-growing. 0

Filamentous algae and Enteromorpha were the only other aquatic plantsfound during this survey. 0

Diversity of marginal communities is notable here. Scirpus maritimus, Schoenoplectus lacustris ssp tabernaemontani and Phragmites swamps occur west of therocky 0 promontory on the north shore and more extensively at theeastern end of the Lough, associated with the major freshwater inflow. 0 Juncus maritimus dominated salt tolerant community occurs above low peatcliff along much of the northern shore. Exposed bedrock forms most ofthe southern shore with one open stony area of Eleocharis palustris dominated salt tolerantvegetation. D Puccinellia maritima- Glaux maritima saltmarsh borders the lagoon on its low,sandy western shore. 0 This would seem to be a particularly species-poor lagoon butdeeper areas of the eastern and central areas were not surveyed and could containadditional species. a Full aquatic survey is recommended. 0

a

0

0

0

0

0

29 0 J

Corragaun Lough

17.4 ECOTONAL COLEOPTERA J.A.Good Ph.D MIEEM FRES, n Terrascope Environmental Consultancy, Riverstick, Co. Cork J 17.4.1 Site Description

Coastal brackish lake with sandflats and inlet channel crossed bynarrow disued artificial cobble trackway, with seawater incursion into lake at least at springtide. Lake shore with boulders, cobbles, medium-textured sand and peat margins. Sheep pasture on peatysoil with rock outcrops surrounding lake. Stands of Juncus maritimus on deep peatwith cliffs to sand; also mixed sand/organic pasture. Inflow river to lake with large watershed.

Subsites (see Fig. 17.4. 1)

1. Juncus maritimus (L 748699) Approx. 0.1 ha of Juncus maritimus on sandy peat, onc. 0.5 - 1.0 m cliff to standing water on sandflat. Dried pools in bare sandy peat with Bledius castings.Water salinity (neap part of tidal cycle, 13 viii 1996) offshore was 7%0.

J 2. Sandflat (L 748699) Mostly anaerobic sandflat sheltered by outcropping rock near Subsite 1. jn

17.4.2 Methods n Site Rating using Indicator Species LL Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these 7-1 processes. U As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. J Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

30 u

0

0

D

0

0

0

0

0

0

0

0

0

0

0

0

Fig. 17.4.1 Map of sampling sites (Carabidae and Staphylinidae)at Corragaun Lough, Co. Mayo 0 1 - Pitfall traps, S-vac, Flotation 2 - Ground search 0

0

0 J Corragaun Lough

Interpretation of Indicator Species J Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was M likely to originate from the habitat associated with the lagoonor a surrounding habitat J (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a

Lj categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 17.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter J (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves.

31 U

Corragaun Lough 0

0

TABLE 17.4.1. Details of sampling methods. a

0 Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels; collars used where cattle/horses occur 0 Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth 0 burrow casts observed; agitated soil floated in water Ground search Search of bare soil (< 50% 1 1 hour 0 vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to 0 a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 0 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated 0 with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent. 0 Variety of sampling techniques Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by a other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. C That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site. 0

32 J

Corragaun Lough

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to place and lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the J survey. However, this was planned for, and three sets (6 traps each) were placed at all sites (four sets at some sites), of which two were sorted. There was only one site (Aughinish which has a spring/neap water level variation of >1m) where flooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. J This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks. J Quality control: identification 7 Voucher specimens of indicator species have been retained and willbe deposited in the J National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection. l J References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. J Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for J invertebrate fauna - a definition proposed for use in sitesurveys. Bull. Ir. biogeog. Soc. 14: 48-53. II J Methods used at this site Carabidae and Staphylinidae (Coleoptera) were recorded from : (1) Juncus maritimus area - S-vac suction sampler (13 viii 1996),c. 2m2- (2) Juncus maritimus area- 2 sets of 6 plastic pitfall traps with funnelsand ethylene glycol preservative (13 viii- 27 ix 1996, 28 ix - 17 x 1996); J (3) Juncus maritimus area- Flotation samples of sandy peat dry pool (12 subsamplesof 5 x 5 x 10 cm, 13 viii 1996); n (4) Sandflat - Flotation samples (12 subsamples of 5 x 5x 10 cm, 13 viii 1996). vI Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems.

33 0

Corragaun Lough 0

17.4.3 Results 0 Seven species of carabid, one species of heterocerid and fourteenspecies of staphylinid were recorded, none of which are regarded as indicator species (Table17.4.2). 0

0 TABLE 17.4.2 Carabidae and Staphylinidae (Coleoptera) recorded from Corragaun Lough. Nomenclature follows Lucht (1987) and Lohse and Lucht (1989), withthe exception of Diglotta which follows Good (in preparation). 0

0 Species No. individuals 0 Carabidae

Bembidion mannerheimi Sahlb. 1 Dyschirius politus (Dej.) 2 0 Leistus fulvibarbis Dej. 1

Loricera pilicornis (F.) 1 Nebria brevicollis (F.) 1 0 Notiophilus aquaticus (L.) 1 Pterostichus niger (Schall.) 2

Heteroceridae 0

Heterocerus flexuosus Steph. 21 0 Staphylinidae

Atheta vestita (Grav.) 14 0 Bledius fergussoni Joy 6 Bledius limicola Totth. 9

Carpelimus corticinus (Grav.) 1

Cryptobium fracticorne (Payk.) 1 a

Diglotta mersa (Hal.) 1

Drusilla canaliculata (F.) 1 Ocypus ater (Grav.) 7 0 Ocypus olens (Mull.) 1

Quedius molochinus (Grav.) 1 Sepedophilus nigripennis (Steph.)5 0 Stenus nitidiusculus Steph. 1

Tachinus laticollis Grav. 1 Xantholinus longiventris Heer 3 0

17.4.4 Evaluation 0

Of no recorded conservation interest for terrestrial ecotonal community. 0 (Rating categories : None, low, average, exceptional)

34 J

J Corragaun Lough

Scientific Argument for Rating

Indicator species were absent.

1 17.4.5 References

Lohse, G.A. and Lucht, W.H. (1989) Die KaferMitteleuropas. 12. 1.Supplementband mit Katalogteil. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die KaferMitteleuropas. Katalog. Goecke & Evers, Krefeld.

J

J

J

35 Corragaun Lough

17.5 SUMMARY AND EVALUATION

Corragaun Lough is a completely natural sedimentary lagoon with anatural tidal inlet and is therefore a site of international importance basedon the Habitats Directive. rl The lake lies within the large proposed NHA which includesthe Mweelrea Mountains

LJ (Site 1932).

The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion

Geomorphology Moderate Aquatic Fauna Low J Vegetation Moderate/Potentially High Ecotonal Coleoptera None J Geomorphology J The lake is a small (7 ha), shallow, completely naturalsedimentary lagoon with a long, sinuous tidal inlet in an area of coastline subject todynamic changes in sedimentation patterns. Although the lake is defined as a lagoon, itcould also be considered part of the tidal inlet. Seawater appears to enter on most tidesthrough a long sinuous inlet and the lake water is subject to wide fluctuations in salinity.Thelocality of the inlet and the size of the lagoon have changed considerably in recent years.

Based on size and shape, and distance from the sea,the lake is rated as of moderate conservation value as a lagoon

Aquatic Fauna

The fauna was poor in spite of open contact withthe sea and a gradient in salinity. J Species poverty may be due to wide, and possibly suddensalinity fluctuations. Among 20 taxa recorded, only two were lagoonal specialists. The faunawas dominated by euryhaline and polyhaline species and no limnic species was recorded.

The fauna typified a lagoon subject to strong tidal influencewith regular tidal scouring and no areas allowing low salinity species to survive. Nointeresting or rare species were recorded.

Based on the paucity of species and lagoonal specialists, thelagoon is rated as of low conservation value.

J 36 L

Corragaun Lough 0

Vegetation 0 Ruppia c.f maritima was the only aquatic macrophyte recorded. Itwas low growing and had a wide but patchy distribution. Filamentous algae andEnteromorpha were the only other aquatic plants found during this survey. 0 Diversity of marginal communities was notable. Scirpus maritimus, Schoenoplectus lacustris ssp. tahernaemontani and Phragmites swamps occurred on the northshore 0 and more extensively associated with the major freshwater inflow.

Juncus maritimus dominated salt tolerant community occurred above low peatcliffs 0 along much of the northern shore and there was oneopen stony area of Eleocharis palustris dominated salt tolerant vegetation. Puccinellia maritima - Glaux maritima saltmarsh bordered the lagoon on its low, sandy western shore. 0

This would seem to be a particularly species-poor lagoon butdeeper areas of the eastern and central areas were not surveyed and could containadditional species. It is 0 therefore rated as of moderate but potentially high conservation value.

A full aquatic survey is recommended. 0

Ecotonal Coleoptera 0 Seven species of carabid, one species of heterocerid and fourteenspecies of staphylinid were recorded, none of which are regarded as indicator species. Thesite is therefore of no recorded conservation interest for its terrestrial ecotonal community. 0

Summary 0 Corragaun Lough is a completely natural sedimentary lagoon with along tidal inlet in an area of coastline containing a number of lagoons, and"former lagoons", on the 0 south Mayo coast which vary in their geomorphology and degreeof marine influence. Some are entirely fresh, others saline, while barriers may beof sand or cobbles, or both. Corragaun Lough is the only one of this serieswith a permanent tidal inlet 0 through which the sea enters at each high tide. The post-glacial history of parts of this coastline has beenstudied in detail and continues to be of great interest to geomorphologists. 0 The lough undergoes wide fluctuations in salinity and tidal scourwhich limit diversity of fauna and vegetation. The aquatic vegetation was species poor but therewas a variety of marginal 0 communities. The vegetation of the lake and its surrounds weresurveyed in the 1970s.

The shores are of no conservation value for ecotonal Coleoptera. 0

Corragaun Lough has little conservation value for aquatic fauna andflora on its own but is of interest as the most marine of aseries displaying a range of ecological 0 conditions (see also Roonah L.). It is recommended that thecomplete series of lakes, from L. Polimore in the north to L. Doovilra in the south be designated as a proposed SAC and that further studies of the entire series beundertaken.

37 0 M J COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

(VOLUME 111)

18. ROONAH LOUGH

Brenda Healy Geoff Oliver Pat Hatch Jervis Good

February 1997

D

Prepared for the National Parks and Wildlife Service

(BioMar/Life) 18. ROONAH LOUGH

CONTENTS

18.1 Study Area

18.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

18.2.1 Methods 18.2.2 Results 18.2.3 Discussion 18.2.4 Threats 18.2.5 Evaluation 18.2.6 References

18.3 Vegetation Survey (Pat Hatch)

18.3.1 Site Description J 18.3.2 Methods 18.3.3 Results Shore based survey Transect tables 18.3.4 Evaluation

18.4 Ecotonal Coleoptera (Jervis Good) 11 18.4.1 Site description 18.4.2 Methods 18.4.3 Results 18.4.4 Evaluation 18.4.5 References

18.5 Summary and Evaluation J

Roonah Lough J

18. ROONAH LOUGH, Co. Mayo.

OS Grid Reference: L 755 765, 1:50,000 Sheet No. 37 Alternative names:

18.1 STUDY AREA

Generalfeatures Roonah Lough is situated on the west Mayo coast, 10km north of Killary Harbour and 2 km from Killadoon (Fig. 18.1.1). The Carrowninsky riverdrains into the lagoon from the north and the smaller Bunleemshough river drains intoit from the southeast. Water from the two rivers are impounded by a lowcobble barrier through which a modified natural outlet runs. The lagoon is shallow and sandyaway from the barrier and is bordered to the east by grassland and wetheath. Part of the area at present occupied by the lakemay have been cut for peat. Some areas in the surrounding land have been cut in thepast and are still cut at present on a small scale. The whole coastline from Killary harbour to Roonah Point consistsof a complex and dynamic barrier system of dunes and cobbles with lagoons ofvarious sizes and salinities. Praeger (1934) described the Dooaghtry area only 6 kmto the south and really part of the same system as an area "utterlywindswept" but which "would well repay further study". A report for the Netherlands Commission forInternational Nature Protection describes the Dooaghtry area as unique for Europeand Eire as a landscape, geologically, geomorphologically and botanically (Westermann & Westhoff, 1974). The National Coastline study regarded the area as anexceptional landscape, warranting declaration as a "National Park" or similar. (see Corragaun,Part 17). Roonah is of additional interest as two rivers in whichsalmon spawn run through the lagoon and it also attracts small numbers of waterfowl andwaders.

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate with a smallannual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is6°C in January and 14.5-15.0 °C in July. The growing season (the period of mean daily air temperatures above6 °C) is 8.5 months and as snow and frosts are rare, some plant growthis possible in winter months. Annual rainfall is approximately 2000 mm, and the number ofrain days (1 mm or more) is approximately 200. Winds are mainly from the southwest.Mean annual hourly wind speeds are between 6 and 7 m/s anda maximum wind speed of 50 m/s is estimated to occur once in 50 years. The daily durationof bright sunshine averages 3.5-4.0 hours. Mean relative humidity is around 85% as onall Irish coasts. Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 in (Carter 1992).Maximum

1 u

0 Cleaby Rocks \ I 'I

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f \ 0

Stone - Pi. ,_ ,. Rows !! _ Uarrickyveg sly- _ Aghany __ _ dWyy P nt Ei

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ougn I / 0 - t- 78 x Ne rc

COnOwnisky i T60rAli ;m 1 0

Mogtitthictomb

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- Y--_IT74 _'.- i . . U NIe bore / c. l i s Lou 0 6""°"°"w., ; s 3rahwe I . aVkdM r1 . CI\ Dercnl. --._` - s g I -; 1 Derrygarve Bey _ uowd s ` - r ` I D rraldt e

731 - I` y \ Barnaboun Point ` fr r \I /r: i P.omo mry l t x S ll^ 1 ` . ;lpM Bs y 4 ` I Forr -- \ 8 n -- - - - oel t A ! i Dec 0

\ 1 .fib A1 I,

286 0

° T T ` .

71 0

KJary d 72 74 M 73- 79 U

0 Fig. 18.1.1Section of l50 000 map showing locality of Roonah Lough a J

Roonah Lough J

wave heights (averaging once in 50 years) are 30-35 m (Couper 1983). Tides are semi-diurnal and sea temperatures are lowest in February and highestin August.

Landscape and Geology Bedrock is Ordovician, mica-schist, gneiss and quartzite. Soils are mostly peaty gleys. Inland the steep slopes withshallow soils are of extremely rl limited land use capability (Royal Irish Academy, 1979). Land surroundingthe Lough J consists of some quite large fields of improved pasture, togetherwith smaller fields of wet grassland and heath. Between Roonah and Cross Lough to the south, is anarea of peat which was being cut in 1996. Lake Topography The lagoon is approximately I km from southwest to northeast, 600 m across and covers about 50 ha. Water depthis 25-80 cm over most of the lake with slightly deeper water in the channels draining into andout of the lake. Two rivers enter the lake at the eastern end and run throughthe lake to the northwest. The bed of the lake is mostly composed of sand with more siltand unconsolidated peat at the eastern end where the river enters.

Hydrology The Carrowninsky River drains into the lagoon from the northand the smaller Bunleemshough River drains into it from the southeast. Waterfrom the two rivers are impounded by a low cobble barrier through whicha outlet runs which is natural, though relocated. A road now runs along the oldchannel and a new outlet has been formed.Seawater appears to enter the lake on spring tides onlyand what seawater does enter is soon flushed from the lagoon bythe volume of fresh water entering from the rivers A tidal variation in water levelis noticeable in the outlet channel but is less noticeable in the main body ofthe lake.

Salinity and water quality Despite the fact that seawater enters at regular intervals, the lake isalso likely to receive large volumes of freshwater runoff fromthe surrounding land. Salinity levels may vary considerably, both spatially andtemporally, depending on precipitation and tides. Generally salinity levels are likelyto be relatively low throughout the year with a tendency to increase duringthe summer. However, the peaty soils of the surrounding land would affect the deliverytime of both surface- and ground-water flows to the lake through absorption and slow releaseof water. The prolonged flow of freshwater to the lagoon during the "dry"months may result in J lower salinities than might be expected. On the other hand,winter storms may result in a higher volume of seawater entering the lake and raisingsalinity levels at a time when they might be expected to fall.

Stratification is not likely to occur at any period ofthe year due to the shallow nature of the lake and regular flushing. J The coastal plain in this area appears to be quiteintensively grazed and is likely to receive heavy fertilizer applications. However, flushing of the lagoon byboth fresh- and seawater is likely to restrict any problems of eutrophication.

2 'J

Roonah Lough

18.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin J 18.2.1. Methods

Environmental variables Water depths were measured from an inflatable dinghy.

The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used J are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and J salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o. precision). A photographic record was made of the site andlocal information sought J concerning background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used near stations A and B inorder to gain additional information J concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction.All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic i variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are J sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by

3 U

Roonah Lough 0

inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are 0 purely subjective, and absolute numbers vary between taxa. Several faunal groups were sorted and distributed to specialists. Standardkeys were 0 used to identify remaining specimens, but many of these werelarval or juvenile stages anddifficulttoidentify with certainty. Some groups require adult males for identification and these were often not available due to lowpopulation density and the 0 limited number of individuals collected in the time available. Finally,some soft-bodied groups were particularly difficult to identify when preserved. All Diptera are identified to family level. All Odonata positivelyidentified were IJ Ischnura elegans and it is assumed that early instars ofthis group were of the same species. 0 18.2.2 Results Roonah Lough was sampled on the 14.vi.96 during the firstpart of the survey, and 0 from 15-16.ix.96 during the more intensive survey. 0 Six sampling stations were selected in the lake to reflectthe influences of substrate, and freshwater/seawater inflows. Fig. 18.2.1 shows the position of thesesampling stations in the lagoon. a

Environmental Variables Station A (OS 7488 7644) was located on the westernshoreline at the mouth of the 0 outlet. Water depth varied from 0- 1 m, substrate was mostly sand in the mainchannel with cobbles along the edges of the barrier. Salinity ofthe outflowing water measured 0%0 0 Station B(OS 7517 7623) was located on the southeast shore wherethe Bunleemshough River enters the lagoon. Substrate consisted of sand andfine organic silt, water depth varied from 0- 60 cm and salinity measured 0 %o Station C (OS 7490 7629) was located on the southernshore, closest to the road from Killadoon where a drainage ditch enters the lagoon. Waterdepth varied from 0- 60 cm, substrate was a mixture of peat, silt andsmall stones, salinity measured 0%o Station D (OS 7551 7625) was located on the southeasternshore just north of the Bunleemshough river. Depth varied from 0- 25 cms, substrate was fine sand and silt with occasional stones and salinity measured 0 %o Station E (OS 7539 7687) was located along the northeastshore where a track runs down to a stony beach. Substrate consisted of small stones,fine sand and silt. Cattle use this area and the ground was heavily poached andmanured. Water depth varied from 0 - 10 cms and salinity measured 0 %o. Station F (OS 7527 7738) was located at the northend where the Carrowninsky river enters the lagoon. The river channel is deep at thispoint and only the edges of the channel were sampled. Water depth varied from 50- 125 cms, substrate consisted of silty sand with patches of peat. Salinity measured 0 %o.

0 4 0 J

r, LJ

J 770

J

J

750 Killadoon 2 Km

J Fig 18.2.1Location Map of Sampling Stations inRoonah Lough, Co. Mayo.

J U

Table 18.2.1. Fauna Recorded at Roonah Lough, Co. Mayo. Juneand September 1996. G ( ) = records from June.

EJ Fauna Sampling Stations ( L.T. = light-trap)

A L.T. B C D E F Ei Porifera Cnidaria Turbellaria 0 Nemertea Annelida Hirudinea (+) Crustacea 0 Ostracoda Copepods Cirripedia Ei Mysidacea Neomysis integer a c a a o Isopoda ArnphipodaGammarus duebeni + + 0 Tanaidacea DecapodaCarcinus maenas + Arachnids 0 Insects Thysanura EphemeropteraClown simile + 0 OdonataIschnura elegans + + c Plecoptera + Trichoptera(cases) c + 0 HemipteraCorixidae + + + 1 c + c c Cymatia bonsdorffi + Callicorixa praeusta + 0 Corixa panzeri + Sigara dorsalis + + c c + c c + S. semistriata + 0 S. stagnalis +

Coleoptera o + c o 1 1 c *Agabus montanus 0 *Elmis aenea Haliplus lineatocollis + + E H. wehnckei + + j + *Hvdroporus memnonius Laccobius minutus + Ei Llybiusfuliginosus + Nebrioporusdepresses + + DipteraChironomidae + + + + c c Ei Molluscs j

ProsobranchiaHydrobiidae a c 1 a 1 3 o a

Potamopyrgus antipodarum+ + + + + + j + + + D PulmonataAplexa hypnorum ! + Lymnaea palustris +

L peregra + + 4 ! a Planorbis leucostoma + Sementina complanata + + = present; o = occasional; c = common; a= abundant; F = fyke net 0 * = Stations not known

Ei J

Table 18.2.1. cont.. Fauna Recorded at Roonah Lough, Co. Mayo.June and September 1996. ( ) = records from'June.

Fauna Sampling Stations (L.T. = light-trap) A L.T. B L.T.B C L.T.C D L.T.DI E F Opisthobranchia Bivalvia Pisidium sp. shells Bryozoa Plumatella repens + Echinodermata Tunicata Teleostei Anguilla anguilla + + + 1 + Gasterosteus aculeatus + 10 + 24 + 10 a 95 + Platichthys flesus + + + +

J

J

J

J

J + = present; o = occasional; c = common; a= abundant; F = fyke net u

Roonah Lough 0

Fauna 0 The species recorded at the different stations, using all samplingmethods, are listed in Table 18.2. 1. Among 3 1 taxa listed, 29 areidentified to species. The list comprises 7 euryhaline, 2 oligo-mesohaline and 21 limnic taxa (Table 18.2.2). Onlyone of the 0 species is listed as a lagoonal specialist in Britain (Davidsonet al. 1991). Faunal species were more or less evenly distributed throughout thelake and no 0 gradient between the sea inlet and other stations could bedetected. Neomysis was abundant at all stations and large numbers were taken inlight traps. Corixidae and Potamopyrgus were also common. Most of the limnic species wereconfined to Station 0 F. Sigara dorsalis was the dominant corixid.

Table 18.2.2Ecological categories of the recorded taxa in Roonah Lough (excluding E Trichoptera). L = lagoonal specialist according to Davidson et al.(1991)

Marine None 0

Poly-mesohaline None IJ Euryhaline Neomysis integer Gammarus duebeni Carcinus maenas Sigara stagnalis L 0 Anguilla anguilla Gasterosteus aculeatus Platichthys flesus 0 Oligo-mesohaline Ischnura elegans Potamopyrgus antipodarum IJ Limnic Hirudinea Cloeon simile Cymatia bonsdorffi IJ Callicorixa praeusta Corixa panzeri Sigara dorsalis IJ Sigara semistriata Agabus montanus Elmis aenea Haliplus lineatocollis IJ H. wehnckei Hvdroporus memnonius Laccobius minutus Llybius fuliginosus Nebrioporus depressus Lymnaea palustris L. peregra Aplexa hvpnorum Planorbis leucostoma Sementina complanata Plumatella repens

5 J

Roonah Lough

18.2.3 Discussion

The assemblage typifies a slightly saline lake receiving occasional smallincursions of seawater. Oligohaline and freshwater species predominated. Corixids and beetles were common and diverse. Crabs and flounder were the only speciespresent which can be assumed to have colonised diectly from the sea. Salinity readingsof O%o were recorded on both visits, and it is evident that the brackishwaterspecies present are capable of surviving in freshwater for long periods.

This was the only site at which Cymatia bonsdorffi, Sigarasemistriata, Agabus montanus and Laccobius minutus were recorded. The only species ofinterest is the bryozoan, which needs to be confirmed. None of the speciesidentified can be described as rare in Ireland.

J 18.2.4 Threats

Agriculture in the area is relatively intensive andfertilizer applications are likely to contribute to high nutrient levels in the lake, but flushing,mostly by freshwater but occasionally by spring tides, is likely to prevent severe effectson the invertebrate fauna. Cows graze the shores and cause considerable poaching andmanuring in some areas of the lagoon itself. Some extraction of barrier material appears to be taking place. The present outlet channel appears to have been artificially created.A track now appears to run along the original outlet channel. It maybe that this was done to facilitate access to an amenity area and that efforts arebeing made to encourage tourism.

18.2.5Evaluation

Roonah Lough is a natural sedimentary lagoon with a cobblebarrier and a modified natural outlet. These features qualify it as a site ofinternational importance based on geomorphology.

J The lake lies in an area of coastline subject todynamic changes in sedimentation patterns. It is one of a number of lagoons, and"former lagoons" on the south Mayo coast which vary in their geomorphology and degree of marineinfluence. Some are entirely fresh, others saline, while barriers may be of sandor cobbles or both. Roonah Lough is the only one of this series with anapparently persistent low salinity, rather than being completely fresh or tidal.

The post-glacial history of parts of this coastline has beenstudied in detail and continues to be of great interest to geomorphologists.

The coastal lagoons of this area are of botanical andornithological value. The aquatic fauna characterised a slightly saline lakein which freshwater and oligohaline species predominated. Only one lagoonal specialist was present andonly

6 Roonah Lough 0

the freshwater bryozoan, which awaits confirmation, is ofany special interest among the species identified. 0 The lake has little scientific value except as an exampleof a lagoon evolving into a freshwater lake. Little appears to be known about the toleranceof most freshwater 0 invertebrates to saline influences and this lake, together with othersin the area with various salinity regimes, could provide useful scientific information. The lake is part of a proposed NHA (Site CodeNo. 1529). 0 The lake has little conservation value on its own onthe basis of its aquatic fauna but as one of a series it sheds light on the historyand geomorphological processes of this 0 section of the coastline. It is recommended that the completeseries of lakes, from L. Polimore in the north to L. Doovilra in the southbe designated as a proposed SAC. 0 18.2.6 References and Additional Sources 0 Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Anonymous. 1974. The Scientific Interest of the Area knownas Dooaghtry, Co. 0 Mayo. Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. El Bekkers, A., Brock, Th. & J. Klerkx. 1976. A VegetationStudy of Some Parts of Dooaghtry, Co. Mayo., Republic of Ireland. Unpubl. report. Laboratory of Geobotany, Catholic University ofNijmegen, Holland. 76pp. 0 Cabot, D. 1966. Cephalanthera longifolia in West Mayo. Irish Naturalist'sJournal 15: 156 Cabot, D. 1969. Spiranthes spiralis in West Mayo. Irish Naturalist'sJournal 16: 177 0 Cabot, D. & Ruttledge, R.F. 1967. Liquid Assets' List ofWildfowl Wetlands in the Republic of Ireland of National and International Importance. Irish Wildbird Conservancy, Pub. No. 5. Dublin. 0 Carter, R.W.G.1992 Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. 0 Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. Peterborough, Nature Conservancy Council. Decoy, R., Delaney, C., Carter, R.W.G. and Jennings, S.C. 1996.Coastal stratigraphies as indicators of environmental changes upon European coasts in the late Holocene. Journal of Coastal research 12: 564-588. Delaney, C. and Devoy R. 1995. Evidence from sites inwestern Ireland of late Holocene changes in coastal environments. Marine Geology 124: 273-287. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Goodbody, Q. 1977. Solid Geology of Uggool and Dooaghtry (unpubl.map). Haughton, J.P.1957. Physiography and Climate. In: Meenan, J. & D.A. Webb.(eds.) A View o_f Ireland. Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238.

7 J

Roonah Lough

Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. E,IFA/T23 (Suppl. 1). 507-518. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 PP. Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp. i Praeger, R.L. 1934. The Botanist in Ireland Reprinted in 1974by E.P. Publishing Ltd., Dublin. 398 pp. Praeger, R.L. 1937. The Way That I Went. Hodges, Figgis& Co. Dublin. 174 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 PP.. Westermann, J.H. & V. Westhoff. 1974. Report on the DooaghtryArea. Publication of the Netherlands Commission for International Nature Protection, Amsterdam. 5 pp.

J

8 0

0

0

Plate 18 2.3View of northern part of Roonah Lough showing gavel/sand harrierand inlet of River Carrowninsky. Station F.

Plate 182,4View- of Roonah Lough looking southwest, Stations D (left) andE (right)- 0

Plate 18.2.1View of Roonah Lough in the distance, showing agricultural land and peat cutting (on the left)

Plate 18.?_?View of Roonah Lough showing inlet in the barrier andClare Island. J

Roonah Lough

18. 3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

18.3.1 Site Description(Fig. 18.3. 1)

Roonah Lough is a shallow sandy lagoon set in afairly low-lying landscape. Pastoral farmland borders the lough to the north, south and east.The sea lies beyond low dune grassland to the west.

The Carrownisky River is the main freshwater inflow, approaching fromthe east and discharging into the lagoon at two points at its northernend. A smaller stream, the Bunleemshough River, flows in from the south east. Several ditchesdrain into the lough from surrounding farmland.

Much of the shoreline is low earth cliff, backing alongthe eastern shores to a narrow strip of wet rush and Iris grassland. Scirpus and Schoenoplectusswamp vegetation is confined to fairly sheltered areas of the south and south east shores.

The outlet channel runs from about mid-way along the westernshore.

18.3.2 Methods

Two survey methods were employed in the course of fieldwork: 1. Transects 2. Shore-based survey

1. Transects:

The locality of these is shown in Fig. 18.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together withthe total plant, higher plant and algal cover.

9 0

0

0

0

0

0

0 Epal/Alto

0

0

0

0

River 0

0

0 Doml,aftf species codes

Sc rru5 may 'v-1 L4 0

SckoePlop lecf,45, (aca(5h l;55P. -(fiber iaemovirarl, - r(eoch4ri5ra(u5fri5 - 0 4laux Wlari Imu 0

0 Fig. 183.1 -Rooncj ouo Co MrsQ - Maya- i

0

0 J

J

7 J

J Fig. 18.3.2 Roonah Lough, Co.Mayo:Location of Transects and Shore-based Survey Sections

n J 0

Roonah Lough 0

At the aquatic end of each transect a grapnel wasused to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres. 0 At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of bare sand between it and the waters edge at time of survey. It was feltthat this location method was more accurate and made sample areas more re-locatable than one related to, for instance, high water mark, as this is difficult to establish atmany sites.

In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the transect.

Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species:

Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows:

Domin. 10 91-100% 9 76-90 % 8 51-75 % 7 34-50 % 6 26-33 % 5 11-25 % 4 4-10 % 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals

10 J

Roonah Lough

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100% IV 61-80 % III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy. 7 LJ The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course.

Adjacent habitat and land use was described in general termsand dominant species recorded.

2. Shore-based survey:

The surveyor walked around the entire shore recording aquatic species,marginal communities and adjacent habitats and land use. The results arepresented here as descriptive notes, divided into sections along the shore according tochanges in floristics, substrate and/or adjacent habitat. These points of change aremarked on the site maps.

Aquatic vegetation was surveyed by use of the grapnel andby means of wading where water and/or soft substrate depth allowed. The extent of aquaticsurvey was 10 metres out from the shore (i.e. the reach of the grapnel)except where otherwise stated in the descriptive notes.

A brief site description was written for each lagoon.

Constraints J Time. Restrictions on the time available in which to carryout this survey had the following consequences: J

11 :1 0

Roonah Lough 0 a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; 0 b). Marginal NVC survey was carried out on representative standsonly (see `Methodology'). 0 Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey. 0 Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the 0 second reason for the restriction of this survey, in the main, to the lagoon shores.

Identifications 0

Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Fiaamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University 0 College Galway and Michael Guiry, Professor of Botany, University CollegeGalway

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of 0 charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic 0 macrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'. 0

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection.

0

12 J

Roonah Lough J

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest. J The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

18.3.3 Results 1. Shore-based survey

Section A-B (Transects A and B)

Aquatic: Filamentous algae only- sparse

Sandy substrate

Marginal:Eleocharis palustris- Agrostis stolonifera dominated community. 10- c.80m

Adjacent:Dune grassland dominated by Festuca rubra, Trifolium repens, Plantago lanceolata, Lotus corniculatus

Section B-C (Transect C)

Aquatic: Ruppia maritima - sparse Chara globularis var. virgata- sparse Filamentous algae- sparse

Marginal:50cm earth cliff

Adjacent:Agrostis stolonifera- Potentilla anserina grassland. 10m Grading to Lolium perenne - Holcus lanatus- Cynosaurus cristatus pasture J

Section C-D

Aquatic: Unchanged

Marginal:Eleocharis palustris- Agrostis stolonifera dominated community. 5-10m

Adjacent:Iris psuedacorus- Juncus effusus dominant with frequent Filipendula ulmaria, Rorippa nasturtium-aquaticum, Hydrocotyle vulgaris Grading to pasture as B-C

13 0

Roonah Lough 0

Section D-E 0 Aquatic: Ruppia maritima Chara globularis var. virgata 0 Chara globularis var. annulata Filamentous algae - all sparse 0 Marginal:50cm earth cliff

Adjacent:Agrostis stolonifera - Potentilla anserina grassland. 3-5m 0 Grading to Iris community and pasture as C-D

Section E-F 0

Aquatic: Ruppia maritima - sparse Filamentous algae - sparse 0

Gravel and cobble substrate 0 Marginal: Scirpus maritimus single species swamp. 20x15m Backing Eleocharis palustris swamp. 20x5m. 0 Adjacent:Agrostis stolonifera - Potentilla anserina grassland with Juncus effusus Grading as D-E 0 Section F-G

Aquatic: Species unchanged 0

Silt substrate 0 Marginal:Schoenoplectus lacustris ssp tabernaemontani and Eleocharis palustris swamps. 0 Maximum area c.200m2 50cm earth cliff 0 Adjacent:Agrostis stolonifera - Potentilla anserina grassland Grading to pasture as B-C 0 Section G-H

Aquatic: Species unchanged 0 Sand substrate Marginal:50cm earth cliff Occasional Schoenoplectus and Eleocharis palustris swamps 0 (maximum area c.25m2) Adjacent:Agrostis stolonifera - Potentilla anserina grassland 0 Grading to Iris psuedacorus - Juncus effusus grassland Grading to pasture as B-C 0

14 0 J

Roonah Lough

Section H-I

Aquatic: Unchanged

Marginal:Eleocharis swamp. 25x10m

Adjacent:Unchanged

Section I-J

Aquatic: Unchanged

Marginal:Schoenoplectus single species swamp. 25xl5m

Adjacent:Unchanged

Section J-K

Aquatic: Unchanged

Marginal:50cm earth cliff

Adjacent:Unchanged

Section K-L

Aquatic: Ruppia maritima J Enteromorpha Filamentous algae

Marginal:Scirpus maritimus and Schoenoplectus lacustris ssp tabernaemontani single species swamps. Average 30m Backing low peat cliff (average c.30cm)

Adjacent:Holcus lanatus - Cynosaurus cristatus - Potentilla anserina - Juncuseffusus grassland. Average 8m Grading to Molinia caerulea - Nardus stricta grassland

Section L-M

Aquatic: Unchanged

Marginal:70cm earth cliff

Adjacent:Agrostis stolonifera - Potentilla anserina grassland

15 0

Roonah Lough 0

Section M-N 0 Aquatic: Filamentous algae only 0 Marginal:Eleocharis palustris - Agrostis stolonifera community almost continuous. 1-5m Backing 50cm earth cliff 0 Adjacent:Unchanged 0

0 Section N-O

Aquatic: Unchanged

Marginal:As M-N with occasional_Scirpus maritimus shoots. 5-30m 0 Adjacent:Dune grassland dominated by Festuca rubra, Trifolium repens, Plantago lanceolata, Lotus corniculatus 0

Section O-P 0

Aquatic: Unchanged 0 Marginal:Open Agrostis stolonifera - Glaux maritima community. 2-5m

Adjacent:Unchanged

0

0

0

0

0

0

0

16 J

Roonah Lough

2. Transects

Site: Roonah Lough Transect code: A Location: Outlet to sea Sample point:1 Aquatic - grapnel from shore Sample area: Grapnel only Substrate: Sand

Depth: 50 cm + Salinit : 2arts per thousand NVC communit :----- Height cm Cover 7 LJ Filamentous algae

Description: Filamentous algae only.

Site: Roonah Lough Transect code: A Location: Outlet to sea Sample point: 2 Marginal Sample area: 16m2 4x4 Substrate: Sand and silt

Depth: 20 cm Salinit : 2arts per thousand NVC communit :S 19 Eleocharisalustris swam - A rostis stolonifera sub-community Height cm Cover Total Plant 100

Eleocharisalustris 30 40 A rostis stolonifera 20 60 Glaux maritima 15 5 Juncus articulatus 35 < 1

Description: Species-poor community with Eleocharis and A rostis co-dominant. Dense cover. 10m. Flooded at time of survey. Grading to dune grassland with Festuca rubra, Trifolium re pens,Planta o

lanceolata, Lotus corniculatus dominantbarrier .

J

17 0

Roonah Lough 0

0 Site: Roonah Lough Transect code: B Location: Freshwater inflow Sample point: 1 Aquatic 0-30m out -ra nel 0 Sample area: Grapnel only Substrate: Silt

Depth: 50 cm Salinit : 0arts per thousand NVC communit :----- 0 Hei ht cm Cover

Filamentous algae 0

a Descri tion: Sparse filamentous algae the only aquatic species from0 - 30m out.

0

0 Site: Roonah Lough Transect code: B Location: Freshwater inflow Sample point: 2 Marginal Sample area: 16m2 4x4 Substrate: Sand 0

Depth: 20 cm Salinit : 0arts per thousand NVC communit :S 19 Eleocharisalustris swam - A rostis stolonifera sub-communit 0 Height cm Cover Total Plant 100 0 Eleocharisalustris 40 50 A rostis stolonifera 30 50 Glaux maritima 15 5 0 Juncus articulatus 30 < 1

Description: Dense cover of Eleocharis and A rostis co-dommant in species-p oor community. . 20m. Flooded at time of survey.

18 J rl J Roonah Lough

Site: Roonah Lough Transect code: B Location: Freshwater inflow Sample point: 3 Marginal J Sample area: 16m2 4x4 Substrate: Sand Depth: 0 cm Salinit : ----- n NVC communit : S19 Eleocharisalustris swam - A rostis stolonifera sub-community J Height cm Cover Total Plant 100 7 v Eleocharisalustris 40 50 A rostis stolonifera 30 25 Potentilla anserina 10 5 Trifolium re pens 6 5 Scius maritimus 30 < 5 Glaux maritima 10 < 5 Ranunculus acris 10 < 5 Roria nasturtium-a uaticum 20 < 5 H drocot le vul aris 6 < 5 Galium alustre 15 < 5 Leontodon autumnalis 30 < 5 Juncus articulatus 30 < 5

J Description: Eleocharis - A rostis dominated community with occasional lowgrowing Scir us maritimus shoots. Complete round cover. 50m. Grading to dune grassland with Festuca rubra, Trifolium re pens,Planta o J lanceolata, Lotus corniculatus dominant.

J

J

19 0

Roonah Lough 0

0 Site: Roonah Lough Transect code: C Location: Freshwater inflow - cliff shore Sample point: 1 Aquatic - l Om out 0 Sample area: 16m2 4x4 Substrate: Sand

Depth: 50 cm Salinit : 2arts p er thousand NVC communit : -- --- 0 Height cm Cover Total Plant < 1 Hi her Plant < 1 0

Ruis maritima 8 < 1 0

Algae < 1 0 Chara lobularis var. vir ata 7 < 1

0 Description: Very sp arse cover of Ruis and Chara lobularis. Backing earth cliff- height 50 cm. Backing A rostis stolonifera - Potentilla anserina - Juncus articulatus 0 grassland. 10m. Grading to Lolium erenne - Holcus lanatus- C nosaurus cristatus pasture. 0

0 Site: Roonah Lough Transect code: D Location: Marginal swamps Sample oint: 1 Aquatic - 5m out - grapnel Sample area: Grapnel only Substrate: Silt 0

Depth: 80 cm Salinit : 2arts per thousand NVC communit : Height cm Cover 0

Ruis maritima 0 Filamentous algae

0 Description:

0

0

0

20 0 J

rl`` J Roonah Lough n J

Site: Roonah Lough Transect code: D Location: Marginal swamps Sample oint: 2 Marginal n Sample area: 100m2 10x10 Substrate: Silt j Depth: 70 cm Salinit : 2arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp - S.lacustrisssp tabemaemontani sub-community Height cm Cover Total Plant 25 7 u Schoeno lectus lacustris sstabernaemontani 130 25

rl1 U Description: Open single species Schoeno lectus lacustris swamp. 10m.

7 U n Site: Roonah Lough Transect code: D I U Location: Marginal swamps Sample oint: 3 Marginal Sample area: 60m2 200 - whole stand Substrate: Silt

Depth: 50 cm Salinit : 2arts per thousand NVC communit :S 19 Eleocharisalustris swam - A rostis stolonifera, sub-community Height cm Cover 7 U Total Plant 30

Eleocharisalustris 70 30 A rostis stolonifera 40 < 1 n Juncus articulatus 60 < 1 J f"1 Description: Open cover of tall Eleocharis dominated species-poor vegetation. 3m.

I J Backing earth cliff- height 50 cm. Backing A rostis stolonifera - Potentilla anserina - Juncus articulatus community. 3m. Grading to Lolium erenne - Holcus lanatus - C nosuaruscristatus pasture.

21 0

Roonah Lough 0

Site: Roonah Lough Transect code: E 0 Location: Marginal swam Sample oint: 1 Aquatic - lm out -grapnel Sample area: Grapnel only Substrate: Not known 0 Depth: 80 cm + Salinit : 0arts per thousand NVC communit :----- Height cm Cover 0

Ruis maritima Enteromo ha 0 Filamentous algae 0 Description:

Site: Roonah Lough Transect code: E Location: Marginal swam Sample point: 2 Marginal Sample area: 100m2 10x10 Substrate: Peatsilt 0

Depth: 50 cm Salinit : 0arts per thousand NVC communit : S21 Scius maritimus swam - Scius maritimus su b-community 0 Height cm Cover Total Plant 100 0 Scius maritimus 130 100 0 Description: Dense single species Scius maritimus swamp. 30m. 0

0

0

0

0

0

0

22 0 J

Roonah Lough

Site: Roonah Lough Transect code: E Location: Marginal swam Sample point: 3 Marginal Sample area: 40m2 40x1 - whole stand Substrate: Peatsilt

Depth: 30 cm Salinit : 0arts per thousand NVC communit :S21 Scir us maritimus swam - A rostis stolonifera sub-community Height cm Cover Total Plant 80

Scir us maritimus 100 60 A rostis stolonifera 30 20

Description: lm strip Scir us maritimus swam with more opencover and A rostis stolonifera now resent. Backing 30cm eat cliff. Backing Holcus lanatus- C nosaurus cristatus - Potentilla anserina - Juncus effusus grassland. 7m. Grading to Nardus stricta g rassland with Molinia caerulea, Eriohorum an ustifolium, Succisaratensis, Mentha a uatica, H drocot le vul aris, Narthecium ossifram.

23 a

Roonah Lough 0

18.3.4 Evaluation 0

`Potentially Valuable' 0

This is a shallow sandy lagoon of low salinity attime of survey (0-2 parts per thousand) with a fairly large freshwater input. 0

Ruppia maritima was the only aquatic higher plant species foundat this site.It has a wide 0 distribution but is low-growing and was not found in densebeds. 0 Two charophytes, Chara globularis var. virgata and C.globularis var. annulata,occur close to the north eastern shore, where both species grow at sparsecover with equally sparse Ruppia. 0

Marginal communities show some diversity. Both mixed and single speciesScirpus maritimus and Schoenoplectus swamps are found along parts of the southeastern and southern shores. 0 Eleocharis palustris dominated swamp also occurs here and along thewestern shore. Much of the eastern shore is low earth cliff backing to wetgrassland. 0

Ruppia has a wide distribution here and may occur athigher cover in deeper areas. The 0 presence of two charophyte varieties is notable. This site isconsidered worthy of further survey as this may prove it to be a goodrepresentative of a low salinity sandy lagoon. 0

Full aquatic survey is recommended. 0

0

0

0

0

0

0

0

24 Roonah Lough

18.4 ECOTONAL COLEOPTERA

7 J.A. Good Ph.D MIEEM FRES Lj Terrascope Environmental Consultancy, Riverstick, Co. Cork

18.4.1 Site Description J Coastal brackish lake with natural sand and shingle barrier, withoutflow stream through shingle barrier. Inflow river into lake with large catchment, andoutflow shingle probably regularly disturbed after heavy rain events. Barrier shore of shingleand sand, with small internal sandflat. Lake shore including marsh and grassland above sandand peaty soil cliff margins, with fringing emergents (Schoenoplectus lacustris, Scirpus maritimus) in water.

Subsites (see Fig 18.4. 1)

1. Potentilla/ grass margin (L 749760) Grass, Potentilla anserina, Trifolium sp., Triglochin maritima sward above cliffto Scirpus maritimus in standing water. Not recently or heavily grazed. Salinityof offshore water (13 viii 1996) was 0%0.

2. Sandbank (L 748764) Short-turf grass on sloping sandy bank to shingle/sandy beach withstanding water (after water level rise in lake, 27 ix 1996). Ground cover completeto poor.

3. Sandflat (L 749765) Aerobic sand on upper part of unvegetated sandflat, flooded duringhigh water levels. Salinity offshore of sandflat (14 viii 1996) was 1 %o.

18.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these processes.

J As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excluded as an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

J

25 0

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0 N 0

0

0

loom 0

0

0

0

Fig. 18.4.1 Map of sampling sites (Carabidae and Staphylinidae) atRoonah Lough, Co. Mayo. 0

I- Pitfall traps, S-vac 2 - Pitfall traps 3 - Ground search, Flotation 0

0

0 J

Roonah Lough

Therefore, species were selected as indicators of conservation value if:(1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites. J Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 18.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held

26 0

Roonah Lough 0 pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was 0 effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were 0 fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 0

TABLE 18.4.1. Details of sampling methods. 0

0

Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days 0 glycol preservative and plastic funnels; collars used where cattle/horses occur 0 Cobble samples Cobbles turned 0.5 - 2 in 30 from water margin a Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; agitated soil floated in water 0 Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer 0 substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 0 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), 0 with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent. 0

Variety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare 0 sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. 0

27 0 J

Roonah Lough J That some sites, therefore, had more sampling effort using theseadditional methods is not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site (Aughinish which has a spring/neap water level variation of>lm) whereflooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection. J References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Ir. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : (1) Potentilla anserina margin- S-vac suction sampler (13 viii 1996), c. 2m2; (2) Potentilla anserina margin- 6 plastic pitfall traps with funnels and ethylene glycol preservative (13 viii - 27 ix 1996); (3) Grass sandbank - 6 pitfall traps (27 ix- 17 x 1996); (4) Sandflat - flotation samples (c. 0.17 m2 x 5 cmdepth) and 0.5 h ground search (13 viii 1996).

28 0

Roonah Lough 0 The shingle cobble/sand margins of the outflow channel were cobble-searched,with no carabids or staphylinids (or amphipods) found. 0 Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they 0 are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. 0 18.4.3 Results

Nine species of carabid and fifteen species of staphylinid wererecorded, one species of which 0 is regarded as an indicator species (Table 18.4.2). 0

TABLE 18.4.2. Carabidae and Staphylinidae (Coleoptera) recorded from Roonah Lough. 0 Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), withthe exception of Booth (1988) for Tachyporus dispar. 0

0 Species No. individuals

Carabidae 0

Agonum pelidnum (Payk.) 2 * Bembidion bipunctatum (L.) 1 Indicator species Bembidion pallidipenne (I11.) 2 a Calathus fuscipes (Goeze) 87 Calathus melanocephalus (L.) 7 Calathus micropterus (Duff.) 1 0 Calathus ochropterus (Duff.) 1 Dyschirius politus (Dej.) 1 Pterostichus niger (Schall.) 1 0 Staphylinidae

Atheta elongatula (Grav.) 3 0 Atheta graminicola (Grav.) 8 Atheta melanocera (Thoms.) 3 Atheta volans (Scriba) 3 0 Bledius fergussoni Joy 15 Bledius longulus Er. 14 Euaesthetus laeviusculus Mannh. 1 0 Gabrius subnigritulus (Reitt.) 1

Ischnopoda atra (Grav.) 1 Ocypus aeneocephalus (Geer) 5 Othius melanocephalus (Grav.) 2 a Quedius semiaeneus (Steph.) 14 Tachyporus dispar (Payk.) 6 Tachyporus pusillus Grav. 2 0 Xantholinus linearis (01.) 1

0 29 J

Roonah Lough

Bembidion bipunctatum is a halotolerant shore species, occurring inland andin coastal shingle and brackish water pools (Koch 1989, Hyman and Parsons 1992).It is widespread but local in Great Britain (Hyman and Parsons 1992), and recorded from Ireland(Speight et al. 1982). It occurs from North Africa to west Siberia, and is commonat least in northern Germany, although rarer further west (Freude 1976).

An assemblage of five halotolerant species occurred on the sandflatsand sand banks, all associated with coastal sand or shingle (Table 18.4.3). All thesespecies occur on beaches or intertidal sandflats. Bembidion pallidipenne was found at most coastal lakesandy shores during the initial phase of this survey, and is notconsidered local in Connemara, although it is listed as local in Great Britain by Hyman and Parsons(1992).

TABLE 18.4.3.Halotolerant staphylinid and carabid assemblage from sandflat and sandbank, Roonah Lough (flotation sample, ground search and pitfall traps combined).

Species No. Main biotope

Bembidion bipunctatum 1 Coastal, shingle Bembidion pallidipenne 2 Coastal, sand Bledius fergussoni 15 Intertidal sand Blediuslongulus 14 Foredunes

Dyschirius politus 1 Eurytopic, incl. dunes

18.4.4 Evaluation

Of no recorded conservation interest for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

Scientific Argument for Rating Only one indicator species was found at this site, asingle species represented by a single individual. Although an assemblage of halotolerant species occurred (Table 18.4.3), these are also beach, dune and intertidal species and are not associatedwith lagoonal conditions so the site cannot be rated of value.

30 0

Roonah Lough 0

18.4.5 References 0 Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. 0 Freude, H. (1976) Fam. Carabidae. In: Freude, H., Harde, K.W.and Lohse, G.A. (eds). Die Kdfer Mitteleuropas. 2. Goecke & Evers, Krefeld. Hyman, P. S. and Parsons, M. S. (1992) A reviewof the scarce and theatened Coleoptera of 0 Great Britain. Part 1. UK Nature Conservation Series No. 3,Joint Committee for Nature Conservation, Peterborough. Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. 0 Lohse, G. A. and Lucht, W.H. (1989) Die Kdfer Mitteleuropas.12. 1. Supplementband mit Katalogted. Goecke & Evers, Krefeld. Lucht, W.H. (1987) Die Kdfer Mitteleuropas. Katalog. Goecke & Evers,Krefeld. 0 Speight, M.C.D., Anderson, R. and Luff, M.L. (1982) An annotatedlist of the Irish ground beetles (Col., Carabidae + Cicindelidae). Bull. Ir. biogeog. Soc. 6:25-53. 0

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31 0 J

Roonah Lough

18.5 SUMMARY AND EVALUATION

Roonah Lough is a large (50 ha), natural sedimentary lagoonwith a cobble barrier and a modified natural outlet. These features qualify it asa site of international importance based the Habitats Directive.

The lough is of interest as two rivers in whichsalmon spawn run through it and it also attracts small numbers of waterfowl and waders.

It is part of a proposed NHA (Site 1529).

The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion

Geomorphology Moderate/High Aquatic Fauna Moderate/High Vegetation Potentially High Ecotonal Coleoptera None

Geomorphology

Roonah Lough is a natural sedimentary lagoon impounded by alow cobble barrier. A natural outlet has been relocated as a result of roadconstruction. The lough lies in an J area of coastline subject to dynamic changes in sedimentation patterns.It is shallow and the bed is mostly composed of sand.

J Seawater enters through the inlet on spring tides only andis soon flushed from the lagoon by the large volume of freshwater entering from tworivers. Tidal variation in water level and salinity are low.

As a natural sedimentary lagoon with a cobble barrier, thelake is rated as of moderate to high conservation value

Aquatic Fauna

Among 31 taxa recorded, 29 were identified to species butonly one is a lagoonal specialist. The majority (21 spp.) are limnic taxa.

The assemblage typifies a slightly saline lake receiving occasional smallincursions of seawater. Oligohaline and freshwater species predominated. Corixids and beetles were common and diverse. Crabs and flounder were the only speciespresent which can be assumed to have colonised diectly from the sea. Salinity readingsof 0%o were recorded

32 0

Roonah Lough 0 on both visits, and it is evident that the brackishwaterspecies present are capable of surviving in freshwater for long periods. 0

This was the only site at which Cymatia bonsdorffi, Sigarasemistriata, Agabus montanus and Laccobius minutus were recorded. The only other speciesof interest is 0 the bryozoan, which needs to be confirmed. None of thespecies identified can be described as rare in Ireland. a Despite the low number of lagoonal specialists, is rated asof moderate to high conservation value for its typical low salinity communitylow salinity 0 Vegetation

Ruppia maritima was the only aquatic higher plant species found.It had a wide 0 distribution but was low-growing and was not found in densebeds although it may do so in deeper water. a Two charophytes, Chara globularis var, virgata and C.globularis var. annulata, occurred close to the north eastern shore, where both species grew at sparse cover 0 with equally sparse Ruppia.

Marginal communities showed some diversity. Both mixed and single species Scirpus 0 maritimus and Schoenoplectus swamps are found along parts of thesouth eastern and southern shores. Eleocharis palustris dominated swamp also occurred here andalong the western shore. Much of the eastern shore is lowearth cliff backing to wet 0 grassland.

This site is considered worthy of further survey as thismay prove it to be a good 0 representative of a low salinity sandy lagoon. It is therefore rated as of potentially high conservation value. 0 Ecotonal Coleoptera

Nine species of carabid and fifteen species of staphylinid wererecorded, one species of 0 which is regarded as an indicator species and was representedby a single individual.

Bembidion bipunctatum is a halotolerant shore species, occurring inland andin coastal shingle and brackish water pools. It is widespread but localin Great Britain. and recorded from Ireland. It occurs from North Africa to westSiberia, and is common at least in northern Germany, although rarer further west.

An assemblage of five halotolerant species occurred on the sandflatsand sand banks, all associated with coastal sand or shingle. All these speciesoccur on beaches or intertidal sandflats. Bembidion pallidipenne was found at most coastal lakesandy shores during the initial phase of this survey, and isnot considered local in Connemara, although it is listed as local in Great Britain.

Although an assemblage of halotolerant species occurred, these are alsobeach, dune and intertidal species and are not associated with lagoonal conditionsso the site cannot

33 Roonah Lough

be rated of value. It is rated as of norecorded conservation interest for terrestrial ecotonal community.

Summary

Roonah Lough is a large, natural sedimentary lagoon impounded bya low cobble barrier, with a natural, but partly altered, sea inlet. Itis one of a number of lagoons, and "former lagoons" on the south Mayo coast whichvary in their geomorphology and degree of marine influence. Some are entirely fresh, others saline,while barriers may be of sand or cobbles or both. Roonah Lough is theonly one of this series with an apparently persistent low salinity, rather than being completely freshor tidal.

The post-glacial history of parts of this coastline has beenstudied in detail and continues to be of great interest to geomorphologists.

The aquatic fauna and vegetation characteriseda slightly saline lake in which freshwater and oligohaline species predominated. The lake has scientificvalue as an example of a lagoon evolving into a freshwater lake.

The lake has little conservation valueon its own on the basis of its aquatic faunaand flora but as one of a series it sheds lighton the history and geomorphological processes of this section of the coastline. Roonah is the besttrue lagoon of the series

Overall, the lake on its own is ratedas of moderate conservation value. It is recommended that the complete series of lakes, from L. Polimorein the north to L. Doovilra in the south be designatedas a proposed SAC and that further studies of the entire series be undertaken. J 7 J

J

J 34 J i COASTAL LAGOONS IN THE REPUBLIC OF IRELAND (VOLUME 111)

19. FURNACE LOUGH

Brenda Healy Geoff Oliver Pat Hatch J Jervis Good n u February 1997

U

'-1

Prepared for the National Parks and Wildlife Service u (BioMar/Life) J

19. FURNACE LOUGH

CONTENTS

19.1 Study Area

19.2 Aquatic Fauna (Brenda Healy, Geoff Oliver)

19.2.1 Methods 19.2.2 Results 19.2.3 Discussion 19.2.4 Threats 19.2.5 Evaluation 19.2.6 References

19.3 Vegetation Survey (Pat Hatch)

19.3.1 Site Description 19.3.2 Methods 19.3.3 Results Transect tables 19.3.4 Evaluation

19.4 Ecotonal Coleoptera (Jervis Good)

19.4.1 Site description 19.4.2 Methods 19.4.3 Results 19.4.4 Evaluation 19.4.5 References

19.5 Summary and Evaluation

J

J

J

J J

J Furnace Lough

19. FURNACE LOUGH, Co. Mayo.

OS Grid Reference: L 965 975, 1:50,000 Sheet No. 31 Alternative names:

J 19.1 STUDY AREA

General features J Furnace Lough is situated in the northeast corner of ClewBay, 2 km northwest of Newport. (Fig.19.1.1). The lake forms the lower part of the Burrishoolevalley, separated from the larger Lough Feeagh to the north bya terminal moraine. The two lakes together comprise the Burrishoole Fishery, a fully dedicated researchfishery monitored by the Salmon Research Agency of Ireland (Poole 1994).Lough Furnace is a large, deep oligotrophic lake with a large catchment area.Seawater enters the lake on every tide but the large size of the lakeand the volume of water passing through it ensure relatively low salinities at the surface throughout the year. Parker (1977) described the lake in reference to the biologyof Neomysis integer, De Burgh & Smart (1969) reported on the hydrography of thelake and its planktonic and littoral organisms, and Poole (1994) studied the European eel (Anguillaanguilla ) in the Burrishoole system.

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979)

The region experiences a mild oceanic climate with a smallannual temperature range of only 8°C and frequent cyclonic depressions accompanied by rainand strong winds. The mean daily air temperature is5.5-6.0°C in January and14.5-15.0°C in July. The growing season (the period of mean daily air temperatures above6 °C) is 8.5 months and as snow and frosts are rare, some plant growthis possible in winter months. Annual rainfall is 1200-1600 mm, and the number of raindays (1 mm or more) is approx. 200. Winds are mainly from the southwest. Mean annualhourly wind speeds are between 6-7 m/s and a maximum wind speed of50 m/s is estimated to occur once in 50 years. The daily duration of bright sunshine averages3.5-4.0hours. Mean relative humidity is around 85% as on all Irish coasts.

Marine processes in the area are dominated by long periodAtlantic swell waves with median wave heights of 1.5-3.0 in and frequent cyclonic depressionswhich produce large waves, inshore breakers commonly exceeding 8 in (Carter 1992).Maximum wave heights (averaging once in 50 years) are30-35 in(Couper 1983). Tides are semi-diurnal and the tidal range (MHWS-MLWS) for the area isnot listed (Admiralty Tide Tables). Sea temperatures are lowest in February and highestin August.

Landscape and Geology The valley lies in the heart of the Nephin Begmountain range, which is composed primarily of Dalradian schists, gneiss andquartzites. As the range descends towards Clew bay, the schists and quartzites dipunder Old Red

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Furnace Lough

Sandstone, and then Carboniferous sandstone and limestone.The area was heavily glaciated. Traces of moraine can be seen at the northand north east end of Furnace, and the retreating ice left the area blanketed with asandstone bearing till, the Newport till. The overlying soils are mainly gleys, with peaty gleysand blanket peatlands dominating the mountain slopes to the north (Poole 1994).

Main land uses in the area are sheep and cattlegrazing and forestry. The area is currently undergoing severe hillside erosion due to overgrazing, contributing to acidification and peat siltation of the streams and lakes (Poole1994). Lake Topography The lagoon is approximately 2 km from north to south,2 km at its widest point. Two weirs have been constructed at thesouthern end of the lake between the mainland on each side and Nixon's Island inthe middle. The lake covers approximately 125 ha north of the weirs. Water depth ismostly between 1 and 9 metres but with a deep area of 21 metres inthe north in front of the Salmon Research Station.

Hydrology The hydrology of the lake was studied by Parker (1977).The lough is usually affected by tides greater than MHWN which flood intoit from Clew Bay through the short Burrishoole Estuary. Maximum spring tide rise andfall in the lough is ordinarily about 50 cm. The waters are sharply stratified;a permanent halocline runs from 1-3 m depth down to 8 m, below whichthe water is of constant salinity (about 20%o), anaerobic and stagnant. Plankton and fish are therefore confinedto the aerated surface layers, in which the salinity is generally in therange 0-2 %o (Parker and West 1978).

Salinity and water quality Despite the fact that seawater enters at regular intervals, the lake isalso likely to receive large volumes of freshwater runoff fromthe surrounding land. Salinity levels are likely to vary considerably, bothspatially and temporally, depending on precipitation and tides. Generally salinity levels arelikely to be relatively low throughout the year with a tendency toincrease during the summer. However, the peaty soils of the surrounding land would affectthe delivery time of both surface- and ground-water flows to' the lake through absorption andslow release of water. The prolonged flow of freshwater to the lagoon duringthe "dry" months may result in lower salinities than might be expected. On theother hand, winter storms may result in a higher volume of seawater entering the lakeand raising salinity levels at a time when they might be expected to fall.

The waters are sharply stratified; a permanent halocline runs from1-3 m depth down to 8 m, below which the water is of constantsalinity (about 20%o), anaerobic and stagnant. Plankton and fish are therefore confined to the aeratedsurface layers, in which the salinity is generally in the range 0-2 %o The tough has suffered recent problems of deoxygenation and large-scalefish kills. The area is currently undergoing severe hillside erosion due to overgrazing,contributing to acidification and peat siltation of the streams and lakes (Poole,1994).

J

2 Furnace Lough

19.2. AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin

19.2.1 Methods

Environmental variables The position of each sample area was determined using aGPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S. map andgrid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and J salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1%0 precision). A photographic record was made of the site andlocal information sought concerning the background and recent history.

Faunal Sampling J Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspection ofstones and vegetation for one hour at each station. Perspex light-traps were left overnightat certain stations. These consisted of a perspex box (25x25x25 cm) containing achemical light which glowed for 8 hours. The boxes were constructed in theZoology Dept. at U.C.D. according to the model described by Holmes & O'Connor (1988).Faunal samples were preserved in 70% alcohol and stored for subsequent sortingand identification. Fyke nets were used at stations A, B, E andF in order to gain additional information concerning larger fish species which would not be recorded usingthe above methods. Standard procedure was that followed by Moriarty (1975) and Poole(1994). The nets used are referred to as summer fyke nets and consistof two traps, facing each other, joined by a leader net, mesh size 16 mm. Thetrap at each end consists of two chambers and a cod end with knot to knot meshsizes of 16, 12 and 10 mm., respectively. Nets were generally placed at right angles to freshwaterinflows or tidal inlets in order to trap fish swimming from either direction,All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in the survey are affected bymany environmental and biotic variables including season, state of the tide, weather, nature ofthe habitat and life cycles of the species involved. It is therefore difficult tomake quantitative comparisons between lagoons, or even between stations within the same lagoon,as they are sampled at different times and often with a different samplingmethod. The results of the light-traps come closest to quantitative sampling, but even theseare affected by inter- and intra-specific relationships of the fauna and the non-randomdistribution within the water column. Abundance categories of present, common andabundant are purely subjective, and absolute numbers vary between taxa.

3 0 Furnace Lough 0 Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of these werelarval or juvenile stages and difficulttoidentify with certainty. Some groups require adult males for 0 identification and these were often not available due to lowpopulation density and the limited number of individuals collected in the time available (e.g.Jaera, hydrobiids). Finally, some soft-bodied groups were particularly difficult to identify whenpreserved 0 (turbellarians, leeches). All Diptera are identified to family level. All Odonata positivelyidentified were tJ Ischnura elegans and it is assumed that early instars ofthis group were of the same species. tJ 19.2.2 Results 0 Furnace Lough was sampled on 16.vi.96 during the first partof the survey, and from 20-23.ix.96 during the more intensive survey. Nine sampling stations were selected in. the lake to reflectthe influences of substrate, tJ and freshwater/seawater inflows. Fig. 19.2.1 shows the position of thesesampling stations in the lagoon. 0 Environmental Variables Station A (OS 9603 9748) was located in Bay naWilliam on the west side of the lake 0 (Plate 19.2.3). Water depth varied from 0-1 m, substrate was mostly rocks, large cobbles and coarse sand. Salinity of the outflowing water measured0 - 10%o. 0 Station B (OS 9615 9780) was located in a relativelyisolated pool in the northwest where water from Lough Feeagh enters Furnace (the Salmon Leap).Substrate consisted of stones and sand and fine organic silts inthe deeper or more sheltered 0 areas., water depth varied from 0 - 2 m inthe area sampled and salinity measured 0- 10%0. Station C (OS 9683 9820) was located immediately in frontof the Salmon Research 0 station at the north end of the lake, approximately 100m. offshore. Light-traps were hung from the mooring line of a salmon cage at1.5 m and 5 m depths but no other fJ sampling method was used at this station.Salinity measured 1.8 and17.3 %o, respectively, at these depths on the 12th September. Station D (OS 9719 9813) was located in the northeastcorner of the lake. Substrate 0 consisted of large rocks (20 cm-1 m diam.) with pockets of coarse sand and gravel. Water depth varied from 0 - 1 m, and salinitymeasured 15%0. 0 Station E (OS 9731 9659) was locatedin Black Sod Bay, an area of drowned lowland with boggy banks, and peat substrate with stumps ofsubmerged woodland. Water depth varied from 0- 1.25 m and salinity measured 0 - 10%0. 0 Station F (OS 9669 9556) was located near the weirand outlet to the lake east of Nixon's Island. Water depth varied from 0- 2 m, substrate consisted largely of peat along the bank of the river, with stones and sandfurther out in the channel. Salinity 0 measured 10 - 22%0. 0

0 4

0 J

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Salmon Resear station

::::weir H J

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I Fig. 19.2.1Location Map of Sampling Stations in Furnace Lough, Co. Mayo. J Table 19.2.1. Fauna Recorded in Furnace Lough, Co. Mayo. June and September, 1996. Fauna A L.T.A B L.T.B Sampling Stations C L.T.C D L.T.D ( L.T. = light-trap) E L.T.E F L.T.F G L.T.G H L.T.H I TurbellariaCnidariaPorifera Aurelia aurita o a+ +o + + CrustaceaNemerteaAnnelida Ostracoda _ _ Cirripedi=Copepoda -- - Mysidacea }Neornvsis integerIsopoda Jaera albcfrons - - - C c100 c c100 c c100 0 60 +0 4 0 + c.500 + ___ - _ J. ischiosetosu ___ 0 _ ------I ------o Cc J. nord,nanni + -- 1 -Ainphipoda Lekanes haera hookeri oc c75 0c c.75 oa > 100 c 30 ac 45 +o _ 50 + c.100 + - - - -- AllornelitaG.Corn zaddachiduebeni hiurn pellueida volutator + + + + o+ + + + --- + Tanaidacea _ - Le *Lernbostocheirus longi es ilosus + + + Deca oda Cran on crap on F, 1 1 PalaernonetesPalaemonCarcinus maenas elegans varians F, 26 c 3 1 Arachnida + = present; o = occasional; c = common; a F F L O C DD © O ij O i Cj C-7 O O L * = Station not known - -I = abundant; F = fyke net D D O O C D D Table 19.2.1. cont.. Fauna Recorded in Furnace Lough, Co. Mayo. CI r I E __j C 7 C__j June and September, 1996. C__I E3 C] C-] Fauna Sampling Stations (L.T. = lighttrap) C.3 U U E_ I ] U U U E.=7 U U C 7 A L.T.A B L.T.B C L.T.C D L.T.D E L.T.E F L.T.F G L.T.G H L.T.H Insecta Ephetneroptera Pleco sera Odonata S.2Ischnura elegans +2 (+) + 3 TrichopteraHemiptera Corixidae Notonecta laucum 1 0 H drometra sin norum + _-_ _ Coleo tern HaliGerris*Hy lus lacustrisro ru ores collis memnonius +2+ 0 + + + Diptera Chironoinidae Nebrio*Me asternurnores depresses obscurum + + + + + + Mollusca Prosobrartchia Hydrobiidae Pulmonata Potamo yrgus anti odarurn ----- +c 12+ + a +a +a 75+ +a +3 + + - - + ---- - + - BryozoaOpisthobranchia Bivalvia Mytilus edulis ConopeumAbra sp. seurati + + + + + + TunicataEchinodermata _ _ - _ ------l -- _ Teleostci _ GasterosteusAnguilla anguilla acrdeatus + F, 2 ------F, 1 1 + - _-_ _ _ Plaiichth s lestts F, 6 + F, 2 + 3 + 8 + ------r - + + F, 3 c + 2 + 1 + - Pomatoschistus micros + = present; o = occasional; c = common; a + 1 + * = Station not known + = abundant; F = fyke net_ + + _ 1 0

Furnace Lough 0

Station G (OS 9588 9683) was located in a smallcircular pool southwest of the western weir (Plate 19.2.4). It actually lies outside the mainarea of the lake and a EJ channel runs from the pool to what is locally referredto as the estuary. However, the weir separating the "estuary" from the main body of thelake is artificial and there is 0 only a limited restriction in the flow of water ineither direction. For the purposes of this study the pool is regarded as an integral partof the system.

Station H (OS 9624 9670) was located on the southsideof the western weir. EJ Substrate consisted of rocks and stones of various sizes withpatches of coarse sand and reedbeds of Phragmites. Water depth varied from 0 - 1in along the shore and salinity measured 10 - 12%0. 0 Station I (OS 9634 9689) was located on the northside of the western weir. Substrate consisted of rocks and stones of various sizes with patches of coarse sand and IJ reedbeds of Phragmites. Water depth varied from 0 - 1in along the shore and salinity measured 10 - 12%o. 0 Fauna The species recorded at the different stations, using all sampling methods, are listed in 0 Table 19.2.1. Among 35 taxa listed, 32 are identified tospecies. The list comprises 5 marine species, 5 poly-mesohaline, 12 euryhaline, 2 oligo-mesohaline and 6limnic species (Table 19.2.2). Three of the species are listed asa lagoonal specialists in IJ Britain (Davidson et al. 1991).

Table 19.2.2 Ecological categories of the recorded taxa in Furnace Lough L= a lagoonal specialist according to Davidson et al. (1991).

Marine Aurelia aurita 0 Jaera albifrons Lembos longipes Palaemon elegans EJ Mytilus edulis

Poly-mesohaline Jaera ischiosetosa A llomelita pellucida 0 Leptocheirus pilosus Corophium volutator Crangon crangon 0

Euryhaline Neomysis integer 0 Jaera nordmanni Lekanesphaera hookeri L Gammarus duebeni G. zaddachi IJ Palaemonetes varians L Carcinus maenas Conopeuin seurati L 0 Anguilla anguilla Gasterosteus aculeatus Pomatoschistus microps Platichthysflesus 0

0

5 0 J

Furnace Lough

Oligo-mesohaline Ischnura elegans Potamopyrgus antipodarurn

Limnic Notonecta glaucum Hydrometra stagnorum Gerris lacustris Haliplus ruficollis Megasternum obscurum Nebrioporus depressus

J Most of the common species were widely distributed in thelake with Neomysis, Lekanesphaera, Gammarus zaddachi and Potamopyrgus being common or abundant everywhere. The semi-isolated pool G, where the salinity was lowerthan in the main body of the lake, contained a somewhat different fauna. Thiswas the only station where Hydrometra, and Abra were present and the single specimenof Palaemonetes taken there was the only one recorded for the entirelake. One species of Turbellarian was particularly common at some stationsbut was not identified. This is the only site at which Megasternum obscurum, Sigarafalleni,and Jaera albifrons were recorded.

19.2.3 Discussion

The species assemblage typifies a lagoon with some direct contactwith the sea J allowing entry of jellyfish, prawns, shrimps, crabs and flatfish. Mostof the species are characteristic of brackishwaters in the middle salinity range and thoseassociated with higher or lower salinities were mostly present in low numbersonly. Potential colonists from the sea or the mouth of the outlet maybe inhibited from entering the lake by the two weirs. The relatively low number of oligohaline and freshwaterspecies in such a large system, into which flow a number of streams, issurprising and indicates that tidal waters reach to all parts of the lake. The semi-isolatedpool, in which the salinity was lower than the main body of the lake, may actas a refuge for species less tolerant of high salinity from which they can recolonise the lake whenconditions become tolerable.

The essentially brackish nature of the system as a whole,and the relatively high faunal diversity, were unexpected because previous studies (Parker 1977, Parker andWest 1979) had described a highly stratified lake containing a poorfauna dominated by a few abundant species with Neomysis integer and Palaemonetes varians dominant.

The most interesting features of the fauna were the diversityof Jaera and amphipod species,and the near absence of thenormally ubiquitouseuryhalinespecies Palaemonetes varians. The only previous records of Leptocheirus pilosus inIreland are from Wexford Harbour (Costello et al. 1990) and brackishwaterchannels on the North Slob, Co. Wexford (Devlin 1992). There are only threeIrish records for Lembos longipes (Costello et al. 1990).

6 0

Furnace Lough 0

19.2.4 Threats 0 Peat erosion due to overgrazing by sheep on surrounding hillsis said to be the cause of recent fish kills due to a rise in the levelof the oxycline. 0 It is assumed that any pollution from fish cages wouldsink into the deep, stratified lake. 0 19.2.5 Evaluation 0 Furnace Lough is a large, natural saline lake with anatural but modified tidal inlet. The hydrology of the lough is of interest for thepresence of a permanent stratification 0 It is of great importance as a salmon fishery andits environment and fish populations are closely monitored by the Salmon Research Agency. Little wasknown about the invertebrate fauna, however, or the effects on invertebrates of therecent deterioration 0 in environmental conditions. The aquatic fauna comprised marine, euryhaline, oligohaline and freshwater species.It 0 was more diverse than had been expected from results ofa previous survey in 1977, when only one species was in any way abundant. In1996 there was a particularly high diversity of small crustaceans including two rather rare amphipods, 0 Management of the lake as a fishery is not incompatiblewith a thriving invertebrate fauna. a The lake is part of a proposed NHA (Site CodeNo. 1482). Furnace Lough is of high conservation value as a uniquegeomorphological type in Ireland. The presence of a research station on its shoresensures continuous monitoring 0 of environmental conditions. It would be worthwhile taking advantage ofthis facility to carry out simple monitoring of the invertebrates. Its designationas a proposed SAC is recommended. 0

19.2.6References and Additional Sources a Admiralty. 1995. Admiralty Tide Tables: European waters including the Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-313. Carter, R.W.G.1992Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171. Couper, A. (ed.)1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. 0 Peterborough, Nature Conservancy Council. De Burgh, M. & J. Smart. 1969. Report on thehydrography of Lough Furnace and its planktonic and littoral organisms. Ann. Rep. Salmon Res. Trust ofIreland. No. 0 15, Appendix I, 35 -47. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. 0

0

7 0 Furnace Lough

Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 235-238. Hutchinson, C.1986. Watching birds in Ireland. Irish Wildbird Conservancy. 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1,Bord Failte/ An Foras Forbartha. Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T23 (Suppl. 1). 507-518. Parker, M.M. 1977. Lough Furnace, County Mayo; physical and chemicalstudies of an Irish saline lake, with reference to the biology ofNeomysis integer. Ph.D. Thesis, Dublin University. Parker, M. and West, A. B. 1978. The Natural historyof Neomysis integer (Leach) in Lough Furnace, Co. Mayo, a brackish Lough in the westof Ireland. Estuarine and coastal marine Science 8: 157-167. Poole, W.R. 1994. A Population Study of the European Eel(Anguilla anguilla (L.)) in the Burrishoole System, Ireland, with Special Reference to Growthand Movement. Ph.D. Thesis, Dublin University. Praeger, R.L. 1937. The Way That I Went. Hodges, Figgis& Co. Dublin. 174 pp. J Rohan, P.K. 1986. The climate of Ireland. The Stationery Office.146 pp. Royal Irish Academy. 1979. Atlas of Ireland.. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp-- Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp.

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8 ..

0

Plate 19.2-1View of northern end of Furnace Lough showing the SalmonResearch Station.

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40 Plate 19.2 2 View- of Furnace Lough looking southwest r

a

Plate 19 2.3View of northwestern area of Furnace Lough. Station A.

Plate 192 4View of the small pool west of Furnace Lough, StationG Furnace Lough

19.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetation of each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

19.3.1 Site Description(Fig. 19.3. 1)

This is a large lagoon situated at the lower endof a valley which runs down through the Nephin Beg mountain range. The surrounding landscape is rockywith numerous smaller valleys and ridges coming down to the lough shores.

Heath and bog is the dominant vegetation of the areaand borders the lough shores to the east and west. Lower-lying pasture occurs on Inishower andborders the lough to the south. Small patches of broad-leaved woodland occur along thenorthern and southern shores and at the end of a long promontory to the north of Inishower.

An inflow channel at the north western corner brings water into the lough from the larger Lough Feeagh which lies to the north. Several small loughs to the west also supply freshwater to the lagoon. The main inflowing river isthe Yellow River, which discharges into the lagoon about half way along its easternshore.

Shores are generally open and rocky and marginal areas narrow.Phragmites swamp occurs in sheltered areas and as a fringe around twosmall islands in the south.

The outlet to the sea joins the lough at itssouthern extremity.

19.3.2 Methods

This site was surveyd by means of transects only. Thelocality of these is shown in Fig. 19.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A J transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded together with the total plant, higher plant and algal cover.

9 0

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Fig. 19.3.1 _Furhaoe GL4gk , Go. Mccyo -

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0 n u

Fig. 19.3.2 Furnace Lough,Co. Mayo: Location of Transects u

Furnace Lough 0

At the aquatic end of each transect a grapnel was used to attempt to locate additional 0 species and these were recorded. Where no additional species werefound the grapnel survey was not recorded. In some cases, the grapnel wasthe sole method of aquatic survey due to water depth or poor visibility. Here, ofcourse, the results were a 0 species list only with no cover data. The reach ofthe grapnel was 10 metres.

At each aquatic sample point measurements were taken of salinity(using a hand 0 refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes of thissurvey, `the shore' is defined as 0 the marginal vegetation line. This can be both the loughwardedge of a swamp and the loughward edge of saltmarsh vegetation with 50 metres of baresand between it and the waters edge at time of survey. It was feltthat this location method was more 0 accurate and made sample areas more re-locatable than one relatedto, for instance, high water mark, as this is difficult to establish atmany sites. 0 In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for 0 other stands. Sample shape varied according to the shape andsize of the stand. For example, many marginal stands were narrow strips. All plant speciesin the sample area, their average height and percentage cover were recorded. 0

Salinity and water depth were measured and recorded where appropriate.Salinity 0 readings for marginal swamps were taken at the midway pointalong that part of the transect. 0 Representative examples of every marginal community encountered during the course of the survey were sampled using British National Vegetation Classification(NVC) methods for the purpose of subsequent classification. This involved thetaking of five 0 quadrats in each community and the recording of percentage cover(using the Domin scale) and the calculation of frequency for each species: a Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows: 0

Domin. 10 91-100% 9 76-90 % 0 8 51-75 % 7 34-50 % 6 26-33 % 0 5 11-25 % 4 4-10 % 0 3 <4 % -many individuals 2 <4 % -several individuals 1 <4 % -few individuals a

0

10 J

Furnace Lough

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

Frequency V 81-100% IV 61-80 % III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the time of this survey. Therefore, these communities have not been determined. Swamp communities were determined according to the NVC `Swamps andTall Herb Fen' volume.

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were located atthe outlet to the sea (where present) and the major freshwater inflow (where present)as a matter of course. J Adjacent habitat and land use was described in general termsand dominant species recorded. J A brief site description was written for each lagoon.

Constraints

Time. Restrictions on the time available in which to carryout this survey had the following consequences: a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why this is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, in themain, to the lagoon shores.

J

11 0

Furnace Lough 0

Identifications 0 Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service 0

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS 0 Filamentous green algae: due to the difficulty in obtaining determinations,filamentous green algae is recorded in this report as `filamentous algae'.Larger Enteromorpha is recorded simply as `Enteromorpha'. 0

Other algal species were identified by Helen Fazakerley, Phycology Dept.,University College Galway and Michael Guiry, Professor of Botany, University CollegeGalway 0

Nomenclature 0 Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (Third Edition).Scientific names of charophytes are according to N.F. Stewart and J.M. Church, `RedData Books of 0 Britain and Ireland: Stoneworts' (1992). 0 Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading 0 of each site according to specified criteria and recommendations forfurther survey.

The criteria employed in the assessment and grading of eachsite are species 0 composition, diversity and abundance, the presence of rare species andwhether or not a site is representative of a certain `type'. Both aquaticspecies and marginal communities are taken into account, though particular importance is puton aquatic mhcrophytes. Due to the difficulties in obtaining determinations for filamentousgreen algae, such species have not been taken into account here.Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'.

A `Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which this surveyindicates may be of interest and which may prove to be valuable following further survey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-based survey andnot a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Furtheraquatic survey of sites where recommended is to be encouraged.

12 J

Furnace Lough

19.3.3 Results

Site: Furnace Lough Transect code: A Location: Narrow channel near outlet to sea Sample point: 1 Aquatic- grapnel from shore Sample area: Grapnel only Substrate: Not known

Depth: 70 cm + Salinit : 5arts per thousand NVC communit :----- Height cm Cover

Ru is s p. Potamo etonectinatus Enteromor ha Filamentous algae

Descri tion: Narrow channel c. 50m wide). N o emergentor other marginal vegetation. Shore = earth cliff, 80 cm. Backing Molinia caerulea - Juncus acutiflorus - Juncus effusus community.

Site: Furnace Lough Transect code: B Location: Outlet to sea Sample point:1 Aquatic - IOm out -grapnel Sample area: Grapnel only Substrate: Boulders, cobbles,ravel

Depth: 80 cm + Salinit : 20arts per thousand NVC communit :----- Height cm Cover %)

Fucus s p. Enteromo ha Filamentous algae

Description:

13 Furnace Lough 0

0

Site: Furnace Lough Transect code: B 0 Location: Outlet to sea Sample point: 2 Aquatic - 5m out Sample area: 16m2 4x4 Substrate: Boulders, cobbles,ravel

Depth: 20 - 40 cm Salinit : 20 arts per thousand NVC communit :----- Height cm Cover %)

Total Plant 60 0 Fucus s p. 30 50 Enteromor ha 10 5 Filamentous algae 5 0

Description: Fairly high al al cover on stop substrate withFucus dominant. No higher 0 plants resent.

0

Site: Furnace Lough Transect code: B Location: Outlet to sea Sample point: 3 Marginal Sample area: lOm2 10x1 Substrate; Boulders, cobbles,ravel

Depth: 0 - 20 cm Salinit : 17arts per thousand NVC communit :S19 Eleocharisalustris swam - Litorella uniflora sub-community Height cm Cover Total Plant 80

Eleocharisalustris 15 60 Glaux maritima 10 10 Juncus maritimus 50 5 Cochlearia an lica 4 < 1 Litorella uniflora 5 < 1

Description: lm wide strip species- poor salt to lerant communitydominated b Eleocharis alustris with occasional Juncus maritimus tussocks.

14 J

Furnace Lough

Site: Furnace Lough Transect code: B Location: Outlet to sea Sample point: 4 Marginal Sample area: 16m2 (8x2 Substrate: Cobbles, clay

Depth: 0 cm Salinit : -----

NVC communit : Undetermined Height (cm) Cover Total Plant 95

Juncus maritimus 60 30 Juncuserardii 15 20 Festuca rubra 20 20 Tri lochin maritime 10 20 Glaux maritima 10 10 A rostis stolonifera 15 10 Cochlearia an lice 5 < 1

Description: 2m strip of species-poor salt tolerant vegetation dominated bJuncuserardii and Festuca rubra with frequent Juncus maritimus tussocks. Backing c.75 degree slope uto 1 m bank height and grading to Lolium erenne- Holcus lanatus pasture.

Site: Furnace Lough Transect code: C

Location: Weir Sample point: 1 Aquatic - 1 m out -grapnel Sample area: Grapnel only Substrate: Not known

Depth: lm + Salinit : 17arts per thousand NVC commumt :----- Height cm Cover

Ruis s p. Enteromor ha Filamentous algae

Description'.

15 0

Furnace Lough 0

0

Site: Furnace Lough Transect code: C Location: Weir Sam leoint: 2 Marginal Sample area: 100m2 10x10 Substrate: Boulders, cobbles

Depth: 50 cm Salinit : 17arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australis sub-community Height cm Cover 0 Total Plant 90 0 Phra mites australis 220 90

0 Description: Dense single species Phra mites swam forming 10m widestrip on rock substrate, standing c.2m out from the shoreline. Substrate falls awaysharply on lou hward side of stand.

0

Site: Furnace Lough Transect code: C 0 Location: Weir Sam leoint: 3 Marginal Sample area: 16m2 8x2 Substrate: Boulders, cobbles 0 Depth: 0 - 10 cm Salinit : 17arts per thousand

NVC communit : S 19 Eleocharisalustris swam - sub-community undetermined Height cm Cover 0

Total Plant 10 0

Eleocharisalustris 50 5 Glaux maritima 10 < 5 0 Tri lochin maritima 30 < 1 Juncus articulatus 30 < 1 Samolus valerandi 20 < 1 0

Description: Sparse Eleocharis dominated community forming 2m wide strip alongrock 0 shore. Backing to wet heath vegetation with Sphagnum s pp., Moliniacaerulea, Calluna vulaaris, Erica tetralix, Tricho horum ces itosum. 0

0

0

16 0 J

Furnace Lough

Site: Furnace Lough Transect code: D Location: Exposed promontory head Sample point:1 Aquatic - 2m out- grapnel Sample area: Grapnel only Substrate: Cobbles,ravel

Depth: 70 cm + Salinit : 4arts per thousand

NVC communit : ----- Height cm Cover

Ruis s p. Chara as era var. as era Enteromor ha Filamentous algae

Description:

Site: Furnace Lough Transect code: D Location: Exposed promontory head Sample point: 2 Marginal Sample area: IOm2 10x1 Substrate: Boulders, cobbles,ravel

Depth: 0 - 25 cm Salinit : 4arts per thousand

NVC communit : Undetermined Height cm Cover

Total Plant 30

Litorella uniflora 5 25 Isole es cernua 6 < 5 A rostis stolonifera 20 < 5

Bare substrate

Cobbles 60 Boulders 5 Gravel 5

Description: Sparse Litorella dominated shore community forming lm wide strip,flooded at time of survey. Backing steep earth bank c. 80 degrees to 2.5m height)and Alnus lutinosa - Fraxinus excelsior woodland.

J

17 0

Furnace Lough 0

0

Site: Furnace Lough Transect code: E

Location: Sheltered bay Sample point: 1 Aquatic - 40m out - grapnel Sample area: Grapnel only Substrate: Not known 0 Depth: lm + Salinity: ot known

NVC communit : ----- Height cm Cover 0

Ruis s p. Potamo eton ectinatus 0 Filamentous algae 0

Description: 0

a

Site: Furnace Lough Transect code: E Location: Sheltered bay Sample point: 2 Aquatic - 20m out - grapnel 0 Sample area: Grapnel only Substrate: Not known Depth: c. lm Salinit: Not known 0 NVC communit : Height cm Cover 0 Ruis s p. Enteromo ha Filamentous algae 0

Description: Same species found b grapnel survey from 10m outand from shore 0

0

0

0

0

0

18 J

Furnace Lough

n Site: Furnace Lough Transect code: E J Location: Sheltered bay Sample point- 3 Marginal Sample area: lOm2 (10x1 Substrate: Sand, boulders

Depth: 20 cm Salinit : 5arts per thousand NVC communit :S 19 Eleocharisalustris swam- Litorella uniflora sub-community Height cm Cover (%) Total Plant 50 J Eleocharisalustris 25 40 A rostis stolonifera 15 10 Samolus valerandi 15 < 1 Litorella uniflora 5 < 1 Isole es cernua 6 < 1 Juncus articulatus 30 < 1

Bare substrate 50

Sand 40 Boulders 10

Description: Eleocharis dominated shore community forming lm strip around bahead. Backing 45 degree bank of eat and boulders, backing towet heath vegetation - dominant species - Calluna vul aris, Molinia caerulea, Potentilla erecta,Erica tetralix, Sphagnum s

J Site: Furnace Lough Transect code: F Location: Inflow from Lough Fea h Sample point:IAquatic - 7m out - grapnel Sample area: Grapnel only Substrate: Not known

Depth: lm + Salinit : 0arts per thousand NVC communit :----- Height cm Cover (%)

Ruis s p. Filamentous algae

Description:

19 0

Furnace Lough a

Site: Furnace Lough Transect code: F Location: Inflow from Lough Fea h Sample point: 2 Marginal 0 Sample area: 50m210 x 5 Substrate: Peat Depth: 30 cm Salinit : 0arts p er thousand 0 NVC communit :S4 Phra mites australis swam- sub-communit y undetermined Height cm Cover 0 Total Plant 100

Phra mites australis 230 100 0 A rostis stolonifera 40 < 1 L hrum salicaria 60 < 1 0 Mentha a uatica 40 < 1 H drocot le vul axis 30 < 1 0

Description: Dense species-poor Phra mites swam with sparse freshwater associates.7m. Substrate dropping away steeply at lou hward edge of swamp. 0

Site: Furnace Lough Transect code: F a Location: Inflow from Lough Fea h Sample point: 3 Marginal Sample area: 100m2 10x10 Substrate: Peat

Depth: 0 cm Salinit : ----- NVC communit :Undetermined Height cm Cover %) a

Total Plant 100 0 Phra mites australis 200 80 Molinia caerulea 80 95 a Erica eri ena 140 5 M ricaale 100 5 Angelica s lvestris 120 5 L hrum salicaria 50 < 1 Mentha a uatica 40 < 1 H drocot le vul aris 30 < 1 0 Fili endula ulmaria 120 < 1 Potentillaalustris 30 < 1 Osmunda re alis 100 < 1 0

Description: Dense Phra mites and Molinia co-dominant withsparse fen vegetation 0 including shrubby understore which increases its cover to landward.Extending about 100m back from the lou h. Grading to wet heath vegetation with Molinia, Tricho horumces itosum, 0 Calluna vul aris, Erica tetralix, Erio horum an ustifolium, Sphagnums pp.. 0

20 0 J

Furnace Lough

Site: Furnace Lough Transect code: G Location: Freshwater inflow Sample point: 1Aquatic - 100m out -grapnel Sample area: Grapnel only Substrate: Not known

Depth: lm + Salinit : 5arts per thousand NVC communit :----- Height cm Cover

Ruis s p. Chara as era var. as era

Descri tion:

J

Site: Furnace Lough Transect code: G Location: Freshwater inflow Sample point: 3 A quatic - 25m out n Sample area: 16m2 4x4 Substrate: Gravel

U Depth: 50 cm Salinit : 4arts per thousand ----- n NVC communit : Height cm Cover U Total Plant < 1 Hi her Plant < 1 rl J Ruias . 8 <1

J Algae < 1

r-t Chara as era var. as era 6 < 1 U Enteromo ha < 1 Filamentous algae < 1

7U Descri tion: Very sparse low growing Ruis and al al species. More or less unchanging to about 5m out. o aquatic species found 40-c.80m out) n U

J

J

21 0

Furnace Lough 0

0

0 Site: Furnace Lough Transect code: G Location: Freshwater inflow Sample point: 4 Aquatic- 5m out 0 Sample area: 16m2 (4x4 Substrate: Gravel

Depth: 40 cm Salinit : 4arts per thousand

NVC communit : ----- 0 Height cm Cover

Chara as era var. as era 6 < 1 0

Description: Sparse Chara only from 5m out to shore. 0

0

0 Site: Furnace Lough Transect code: G Location: Freshwater inflow Sample point: 5 Marg inal Sample area: 10m2 10x1 Substrate: Sand clay 0

Depth: 20 cm Salinit : 4arts per thousand NVC communit :S 19 Eleocharisalustris swam- Litorella uniflora sub-communti Height cm Cover (% a Total Plant 100 0 Eleocharisalustris 30 50 A rostis stolonifera 20 40 Litorella uniflora 6 10 0 Juncus articulates 30 5 Tri lochinalustris 15 < 1 0

Description.- Dense cover of species-p oor shoreline vegetation forming lmwide strip, with Eleocharis and A rostis co-dominant. a Backing 50cm earth cliff. Backing Juncus effusus- A rostis stolonifera - Potentilla anserina communit . a

a

0 22 J

Furnace Lough

Site: Furnace Lough Transect code: H Location: Sheltered bay Sample point:1 Aquatic - 5m out - grapnel Sample area: Grapnel only Substrate: Boulders, cobbles,ravel

Depth: 80 cm + Salinit : 5arts per thousand NVC communit :----- Height cm Cover %)

Potamo etonectinatus Ruis s p. Enteromor ha Filamentous algae

Description:

Site: Furnace Lough Transect code: H Location: Sheltered bay Sample point: 2 Marginal J Sample area: IOm2 5x2 Substrate: Boulders, cobbles,ravel

Depth: 0 - 20 cm Salinit : 5arts per thousand NVC communit :Undetermined Height cm Cover Total Plant 25

A rostis stolonifera 20 15 Eleocharisalustris 40 10 Glaux maritima 10 5 Tri lochin maritima 20 < 1 Juncus articulatus 30 < 1 rl Description: Fairly sparse, open cover of species-poor Eleocharis- A rostis dominated LJ shoreline community forming strip of 2m width. Backing to wet heath vegetation with Molinia caerulea, Calluna vularis, Erica tetralix, M ricaale and Sphagnum s pp..

23 0

Furnace Lough 0

19.3.4 Evaluation 0 `Potentially Valuable' 0 This large, deep lagoon was surveyed by transects only. Therefore,the information available upon which to make this assessment is limited comparedto most other sites. 0 Ruppia has a wide distribution, being found at all transectsites but that at the mouth of the outlet to the sea. Ruppia maritima occurs here andone sample has been determined as Ruppia c.f cirrhosa. 0

Potamogeton pectinatus occurred at two transect sites, one in asheltered south eastern bay and the other in the narrow channel south ofInishower. 0

Litorella uniflora occurred at three sites and was associated withan Eleocharis palustris swamp community. 0

Chara aspera var. aspera was found in two places, anexposed promontory head and the nearby mouth of the Yellow River. 0

A Fucus species occurred at the mouth of the outletchannel. No aquatic higher plants were found here. 0

There is little variation in marginal vegetation. Marginal areas aretypically narrow and 0 rocky. Phragmites swamp occurs at the inflow from Lough Feeagh,in sheltered bays and fringing the two small southern islands. These are typicallyof open cover. 0 Furnace Lough is a site of notable environmental variation. Salinitylevels at time of survey were 0-5 parts per thousand in the main bodyof the lough but rose to 17-20 parts per thousand in the more enclosed south west quarteraround the weir north of 0 Inishowen and the outlet channel. This is also a relativelydeep lagoon. This survey indicates an interesting species composition. For these reasons, a morethorough survey of its aquatic plant life is desirable. 0

Full aquatic survey is recommended. 0

0

0

0

0

24 a J

Furnace Lough

19.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES Terrascope Environmental Consultancy, Riverstick, Co. Cork

19.4.1 Site Description

Large complex brackish low-tidal amplitude lake with modern bridge barrieron one inlet (Plate 1) and abandoned stone trackway with narrow cut channel barriersat another inlet, in drumlin landscape. Lake shore mostly with boulder/cobble/pebble margin or soil cliffand Schoenoplectus lacustris and Phragmites communes in sheltered shores. One area(Nixon's Is.) with Alnus glutinosa carr at shore.

Subsites (Fig 19.4. 1)

1. Alnus glutinosa foreshore (1.966965) Plates 2 & 3 Sheltered cove backed by Alnus glutinosa carr, with Schoenoplectus lacustrisin offshore standing water, and with grass, Eleocharis sp., etc. ground cover.Also area of cobbles covered with bleached filamentous algae. J 2. Grass bank (L 966964) Bank c. 0:7 in above cliff to open standing waterwith grasses incl. Molinia carulea, Juncus sp., etc. Surface water-table at high spring tide. Subsite closeto inlet bridge (Plate 1).

3. Exposed shore (L 965967) Cobbles on sandy exposed shore, with pasture bank behind. Floodedduring periods of high water. Salinity offshore (14 viii 1996) of 6%o. J 19.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach in thisColeoptera survey is to use selected species to indicate that sites are ecologicallywell-developed with relatively undisturbed natural processes still operating. In particular, it isassumed that this is shown by the presence of assemblages of specieswhich have specialised habitat requirements for habitat features created by physical processes (e.g. aerobicsandflat, 7 washed peat slopes) or biotic responses (algal growth, Scirpus monoculture)to these J processes.

J As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoon sites.

25 0

0

0

a

0

0

0

0

0

0

0

0

0

0

0

0

Fig.19.4.1 Map of sampling sites (Carabidae and Staphylinidae) at FurnaceLough, Co. Mayo. a I. - Pitfall traps 2 - Pitfall traps, S-vac, Cobble search 3 - Cobble search 0

0

0

0 J

Furnace Lough

Therefore, species were selected as indicators of conservation value if: (1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account the numberof individuals of the species present (singletons are often vagrant); (2) The habitatrequirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whether the habitat featuremight be uniquely created by the lagoonal conditions (see Lough Tanai, Section 14, forinstance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. It wouldbe difficult to defend a categorization of sites into any finer categories than this (seeFoster et al. (1992), for instance). Sites were not rated of average value if therewere less than two indicator species present (see argument in Good and Speight 1992).

Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestriallecotonal soil assemblages, and do notrepresent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relative interpretationis based on a reasonably standard sampling effort at each site. Greatersampling effort will probably result in higher numbers of indicator species, but itis assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly- vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity, since muchof the habitat associated with freshwater inflows to the interior of the lagoons would containa soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 19.4.1. Foreach site, a Stihl® BR 400 suction apparatus, mounted on the operator's back, was used. This machine(referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suction sampler) hasa suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects) of 100 x1.5 sec. 'sucks' per subsample were taken at each site, resulting in a total areaof 1.56 m2 covered. Because the hand-held

26 0

Furnace Lough 0

pipe was shaken when the apex of the pipe wasin the vegetation, a larger area (c. 2 m2) was 0 effectively sampled. Sets of six pitfall traps with undiluted ethyleneglycol (commercial anti- freeze) preservative were also dug into the soil at eachsite. Because many of the species expected to occur in such a habitat are adapted toclimbing during flooding, these traps were a fitted with funnels cut and shaped (with tape) from thesame type of plastic cups that were used for the traps themselves. 0

TABLE 19.4.1. Details of sampling methods. 0

a Method Details No. replicates Sampling period, etc. per unit sample 0

Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days a glycol preservative and plastic funnels; collars used where cattle/horses occur a Cobble samples Cobbles turned 0.5 - 2 m 30 from water margin 0 Flotation Samples taken where 24 5 cm x 10 cm x 5 cm depth burrow casts observed; agitated soil floated in water 0 Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site. Samplinginvolved a fixed time ground search (1 hour) during warm dry weather, or a fixed number ofcobbles turned (n = 30) or cliff sods (8 subsamples of 5 x 5 x 10 cm) extracted byflotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn(late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that the speciesoccurring during this period are representative of the sites, even if spring species may beabsent.

Variety of sampling techniques Several techniques will always give a more robust picture of the fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, bare sand, cobbles on sediment, etc.) for flotation, ground search orcobble search. This is regarded as an absence of habitat, rather than an unavailablesampling opportunity. That some sites, therefore, had more sampling effort using theseadditional methods is

27 J

Furnace Lough

not regarded as sampling bias, but a genuine reflection ofthe habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets (6traps each) were placed at all sites (four sets at some sites), of which two weresorted. There was only one site J (Aughinish which has a spring/neap water level variation of >Im) where flooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because the samplingpipe and net becomes wet. The priority for sampling therefore was to visit sites inresponse to dry weather forecasts, thus all sites were successfully sampled using this technique.However, as a result of this strategy, the period that pitfall traps wereplaced varied from site to site. This is not regarded as biasing results to any greatextent, however, as much of the trap sample appears to be obtained in the first twoweeks.

Quality control: identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freshw. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna- a definition proposed for use in site surveys. Bull.Jr. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylinidae (Coleoptera) were recorded from : (1) Alnus glutinosa area- S-vac suction sampler (14 viii 1996), c. 2m2; (2) Alnus glutinosa area- 6 plastic pitfall traps with funnels and ethylene glycol 7 preservative (14 viii- 27 ix 1996); (3) Unvegetated shore near Scirpus maritimus area- cobble search (30 cobbles, 14viii J 1996); (4) Grass bank - 6 plastic pitfall traps (27 ix -17 x 1996).

Species were selected as indicators of conservation value if :(1) they have a restricted habitat preference to a specific type of microhabitat associated with thelagoon margins; and, (2) they

28 0

Furnace Lough a

are reported in the literature as being local or rare,from which it is assumed that they are less likely to survive in historically degraded ecosystems. 0

0 19.4.3 Survey Results

Twelve species of carabid and twenty-one species of staphylinid wererecorded, none of which 0 are regarded as indicator species (Table 19.4.2).

a TABLE 19.4.2. Carabidae and Staphylinidae (Coleoptera) recorded from Furnace Lough. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), andBooth (1988) for Tachyporus dispar. 0

Species No. individuals 0

Carabidae 0 Agonum fuliginosum (Panz.) 1 Agonum gracile (Gyll.) 5 Agonum pelidnum (Payk.) 14 0 Agonum viduum (Pant.) 1 Elaphrus cupreus Duff. 7 Loricera pilicornis (F.) 3 Nebria brevicollis (F.) 4 0 Platynus albipes (F.) 14 Pterostichus diligens (Sturm) 2 Pterostichus melanarius (Ill.) 5 0 Pterostichus niger (Schall.) 16 Pterostichus nigrita (Payk.) 2

Staphylinidae 0

Anotylus rugosus (F.) 1 Atheta elongatula (Grav.) 1 0 Atheta volans (Scriba) 2 Deubelia picina (Aube) 2 Lesteva sicula Er. 1 0 Ocypus olens (Mull.) 1 Oxypoda elongatula Aube 3

Philonthus carbonarius (Grav.) 1 Philonthus cognatus (Steph.) 3 a

Quedius fuliginosus (Grav.) 1 Quedius molochinus (Grav.) I Stenus bifoveolatus Gyll. 15 G Stenus brunnipes Steph. 1

Stenus canaliculatus Gyll. 1

Stenus fulvicornis Steph. 1 Stenusjuno (Payk.) to 0 Stenus nitidiusculus Steph. 13 Stenus similis (Hbst.) 3 Stenus tarsalis Ljungh 1 0 Tachinus signatus Grav. 6

Tachyporus dispar (Payk.) 1 0

29 Furnace Lough

19.4.4 Evaluation

Of no recorded conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional]

J Scientific Argument for Rating

J Indicator species were absent.

19.4.5 References

Booth, R.G. (1988) The identity of Tachyporus chrysomelinus (Linnaeus) andthe separation of T. dispar (Paykull) (Coleoptera; Staphylinidae). Entomologist 107: 127-133. Lohse, G.A. and Lucht, W.H. (1989) Die KdferMitteleuropas. 12. 1.Supplementband mit Katalogteil. Goecke & Evers, Krefeld. J Lucht, W.H. (1987) Die KdferMitteleuropas. Katalog. Goecke & Evers, Krefeld.

J

J

30 1

Furnace Lough 4

F

Plate 1 Bridge over inlet at Furnace Lough, Co. Mayo J r

Plate 2 Subsite 1 - sheltered cove at Furnace Lough, Co. Mayo Furnace Lough 5

a

Plate 3 Cobbles covered with algae at Furnace Lough, Co. Mayo h

F

a

J J

Furnace Lough

19.5 SUMMARY AND EVALUATION

Furnace Lough is a large (approx. 125 ha), natural salinelake with a natural but modified tidal inlet.

It is of great importance as a salmon fishery andits environment and fish populations are closely monitored by the Salmon Research Agency.

The lough is part of a proposed NHA (Site 1482).

The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modified fromthe original rating system which varied for each criterion

Geomorphology High Aquatic Fauna Moderate Vegetation Potentially High Ecotonal Coleoptera None

J Geomorphology

The tough lies in a heavily glaciated area. It islarge and deep, reaching 21 m at its inland end, opening to the sea by a modified, shallowtidal inlet. The hydrology of the lough is of interest for the presence of a permanentstratification with a halocline at 1- J 8 m. It is affected by tides greater than MHWNwhich flood into it through the short Burrishoole Estuary but their effect is controlled by two weirs.The maximum tidal range is c.50cm. There are considerable variations in salinity bothtemporally and J spatially.

The tough is a good example of a deep, stratifiedsaline lake in a natural state and is therefore rated as of high conservation value.

Aquatic Fauna

Among 35 taxa recorded, 32 were identified to species andthree are lagoonal specialists. The fauna comprised marine, euryhaline, oligohaline and freshwater species but only mysids, sphaeromids and flatworms were at all common.The fauna was, however, more diverse than had been expected from results ofa previous survey in 1977, when only one species was in any way abundant.

The species assemblage typifies a lagoon with some direct contactwith the sea allowing entry of jellyfish, prawns, shrimps, crabs and flatfish. Mostof the species are characteristic of brackishwaters in the middle salinity range and thoseassociated with higher or lower salinities were mostly present in low numbersonly. Potential colonists

30 Furnace Lough 0 from the sea may be inhibited from entering the lakeby the two weirs. The relatively low number of oligohaline and freshwater species in such alarge system, into which 0 flow a number of streams, is surprising and indicates thattidal waters reach to all parts of the lake. A semi-isolated pool, in which the salinitywas lower than the main body of the lake, may act as a refuge for species lesstolerant of high salinity from which they 0 can recolonise the lake when conditions become tolerable. 0 The most interesting features of the fauna were the diversityof Jaera and amphipod species. The only previous records of Leptocheirus pilosus in Irelandare from Wexford Harbour and brackishwater channels on the North Slob, Co.Wexford. There 0 are only threeIrishrecords for Lembos longipes. However, these interesting crustaceans were all confined to the southern end near thesea inlet. 0 The aquatic fauna is rated as of moderate conservation valuebased on its relatively high diversity in certain areas and the presence of rareand unexpected crustaceans. 0 Vegetation 0 The lake was surveyed by transects only. Therefore, the informationavailable upon which to make this assessment is limited compared with mostother sites. 0 Ruppia had a wide distribution, being found in all areasexcept the mouth of the outlet to the sea. Ruppia maritima occurred here and one samplehas been determined as Ruppia c. f. cirrhosa. Potamogeton pectinatus occurred at two sites.Chara aspera a var. aspera was found in two places. A Fucus specieswas present at the mouth of the outlet channel but no aquatic higher plants were found here. 0 Marginal areas are typically narrow and rocky and there waslittle variation in marginal vegetation.Litorella uniflora occurred at three sites and was associated withan Eleocharis palustris swamp community. Phragmites swamp occurred at the inflow 0 from Lough Feeagh, in sheltered bays and fringing the twosmall southern islands. These are typically of open cover. 0 This survey indicates an interesting species composition and a morethorough survey of its aquatic plant life is desirable. It is thereforerated as of potentially high conservation value. 0

Ecotonal Coleoptera 0 Twelve species of carabid and twenty-one species of staphylinid wererecorded, none of which are regarded as indicator species. a The lake is therefore rated as of no conservation valuefor ecotonal Coleoptera. 0 Summary

Furnace Lough is a large, natural saline lake with anatural but modified tidal inlet. It 0 resembles a sea lough but is unusual in being permanentlystratified. 0 31 0 J

Furnace Lough

The aquatic fauna was poor throughout the main body ofthe lake but more diverse than indicated by previous studies with a high diversity ofcrustaceans near the inlet.

The vegetation survey indicated an interesting species composition but furtherstudy of the aquatics is needed.

The lake is of great importance as a salmon fisheryand its environment and fish populations are closely monitored by the Salmon Research Agency. It would be worthwhile taking advantage of this facility to carry out simplemonitoring of the invertebrates and further investigations of the aquatic flora. Management ofthe lake as a fishery is not incompatible with a thriving invertebrate fauna.

The lake is of high conservation value as a uniquegeomorphological type in Ireland and the presence of a research station on itsshores ensures continuous monitoring of environmental conditions Overall it is rated as ofhigh J conservation value and its designation as a proposed SAC isrecommended.

7 !J

32 J

COASTAL LAGOONS IN THE REPUBLIC OF IRELAND

VOLUME III

20. DURNESH LOUGH

BRENDA HEALY GEOFF OLIVER PAT HATCH JERVIS GOOD

February 1997

Prepared for the National Parks and Wildlife Service

J

J This volume contributes to BioMar, a project part-funded by the European Commission under the LIFEprogramme

J J

20. DURNESH LOUGH

CONTENTS

20.1 Study Area

20.2 Aquatic Fauna (Brenda Healy, Geoff Oliver) J 20.2.1 Methods 20.2.2 Results 20.2.3 Discussion 20.2.4 Threats 20.2.5 Evaluation J 20.2.6 References

20.3 Vegetation Survey (Pat Hatch)

20.3.1 Site Description 20.3.2 Methods 20.3.3 Results Transect tables 20.3.4 Evaluation

20.4 Ecotonal Coleoptera (Jervis Good)

20.4.1 Site description 20.4.2 Methods 20.4.3 Results 20.4.4 Evaluation 20.4.5 References

J 20.5 Summary and Evaluation

J

7 LJ J

Durnesh Lough J

20. DURNESH LOUGH, Co. Donegal.

20.1 STUDY AREA

OS Grid Reference: G 878 695 1:50,000 Sheet No. I1 Alternative names:

General features Durnesh Lough is located in the eastern part of DonegalBay, 10 km northof Ballyshannon and 5 km east of Ballintra (Fig. 20. 1.1). The lake is impounded by a barrier of high sand-dunes which have filled thegap between two drumlins. A channel and then a pipe runs through the dunes whichallows water to drain from the lake and for seawater to enter at least duringspring tides and storms. The surrounding area consists of sandhills, sand covered drumlins, extensive reedbeds and large areas of wet grassland. Main activities affecting thelake are wildfowling, some reed cutting for thatch, cattle grazing on the wetgrasslands and some angling. The lagoon is regarded as one of the most importantwildfowl sites in Donegal and at times holds internationally important numbers of Scaup (Aythya marila)and Greenland White-fronted Goose (Anser albifrons flavirostris) and regionallyor locally important numbers of all three species ofswans and several other species of waterfowl. Bewick's swans (Cygnus bewickii ), Whooperswans (Cygnus cygnus) and Greenland White-fronted geese are all Annex I species ofthe Birds Directive. The lake is a proposed NHA (Site Code No. 000138).

Climate and oceanographic influences (Climatic data are taken from Rohan 1986 and The RoyalIrish Academy Atlas of Ireland 1979) The region experiences a mild oceanic climate witha small annual temperature range of only 8°C and frequent cyclonic depressions accompanied byrain and J strong winds. The mean daily air temperature is 5.5 °Cin January and 145 °C in July. The growing season (the period ofmean daily air temperatures above 6 °C) is 8 months and as snow and frosts are rare,some plant growth is possible in winter J months. Annual rainfall is approximately 1200mm, and the number of rain days (1 mm or more) is 175-200. Winds are mainly from theSW. Mean annual hourly wind .speeds are between 7-8 m/s and a maximum wind speedof 50 m/s is estimated to J occur once in 50 years. The daily duration of brightsunshine averages hours. Mean relative humidity is around 85%as on all Irish coasts. rl Marine processes in the area are dominated by long periodAtlantic swell waves L_ with median wave heights of 1.5-3.0m and frequent cyclonic depressions which produce large waves, inshore breakers commonly exceeding 8m (Carter 1992). Maximum wave heights (averaging once in 50 years)are 30-35 m (Couper 1984). Tides are semi-diurnal and the tidal range (MHWS-MLWS) Donegal Bayis 3.0 m (Admiralty Tide Tables). Sea temperaturesare lowest in February and highest in August.

1 Rooney Island iBe `. -` lBgacuny /

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Fig. 20.1.1Section of 150 000 map showing locality of Durnesh Lake u

Durnesh Lough cI

Landscape and Geology The underlying geology islimestone but thisis covered by a thick layer of heavy clay drift. Thearea contains numerous drumlins, C parent material is shale and Old Red Sandstone, and soilsare mostly gleys, peaty gleys, inter-drumlin peat and acid brown earths (Royal Irish Academy,1979) E Lake Topography The lagoonisalmost 2 km from northtosouth, approximately 1 km at its widest point and covers approximately70 ha. The lake is shallow with both stony and muddy shores but most ofthe bed of the lake is sand 0 with occasional patches of stone. C Hydrology Small rivers enter the lake at several points along theshoreline of the lake related to the valleys formed between drumlins. The lakewas apparently tidal in the past, but is now impounded by sandhills. Asophisticated channel and pipe J with flapsluice through the dunes has been constructed. The most recent construction is said to date from the 1920s. Seawater flowsthrough the channel to the lake, at least during spring tides. G

Salinity and water quality Despite the fact that seawater enters atregular intervals, the lake is also likely to receive large volumesof freshwater runoff from C the surrounding land. Salinity levels are likely to vary considerably,both spatially and temporally, depending on precipitation and tides. Generally salinity levelsare likely to be relatively low throughout the year with atendency to increase during C the summer.

The lake is shallow and the surrounding land is heavilygrazed in places. Farm E effluents could cause problems of eutrophication, especially at the southernend.

E

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Durnesh Lough J

20.2 AQUATIC FAUNA

Brenda Healy, Geoff Oliver. Dept. of Zoology, University College Dublin J 20.2.1 Methods

Environmental variables Water depths were measured using a plumbline from an inflatabledinghy.

The position of each sample area was determined usinga GPS Personal Navigator (Global Positioning Satellite, Garmin GPS 45). Manufacturers of the GPSstate that J positions can be determined to within 15 meters. It istherefore possible not only to mark the position of sample areas but also to recordchanges in the extent of vegetation and in the morphometry of the barrier and inlets.Names and spellings used are taken from the Discovery Series 1:50,000 O.S.map and grid references refer to the centre of the site. At each sampling station the depth of water and substratetype were recorded, and salinity was measured using a salinity refractometer (No. 1270, Chemlab,U.K., 1 %o precision). A photographic recordwas made of the site and local information J sought concerning the background and recent history.

Faunal Sampling Faunal samples were collected by a combination of sweepnetting (meshsize 0.5 mm), sieving of sediment (1 mm mesh) and close inspectionofstones and .vegetation for one hour at each station. Perspex light-trapswere left overnight at certain stations. These consisted ofa perspex box (25x25x25 cm) containing a chemical light which glowed for 8 hours. The boxeswere constructed in the Zoology Dept. at U.C.D. according to the model described byHolmes & O'Connor (1988). Faunal samples were preserved in 70% alcohol and storedfor subsequent sorting and identification. J Fyke nets were used at stations A, B, C andF in order to gain additional information concerning larger fish species which wouldnot be recorded using the above methods. Standard procedurewas that followed by Moriarty (1975) and Poole (1994). The nets used are referred toas summer fyke nets and consist of two traps, facing each other, joined by a leader net, meshsize 16 mm. The trap at each end consists of two chambers and a cod end withknot to knot mesh sizes of 16, 12 and 10 mm., respectively. Nets were generally placedat right angles to freshwater inflows or tidal inlets in order to trap fish swimmingfrom either direction. All fish were recorded and returned alive whenever possible.

Limitations of Sampling Methods and Species Determination All sampling methods used in thesurvey are affected by many environmental and biotic variables including season, state of the tide, weather,nature of the habitat and life cycles of the species involved. It is therefore difficultto make quantitative comparisons between lagoons, or even between stations within thesame lagoon, as they are sampled at different times and often witha different sampling method. The

3 Table 20.2.1. Fauna Recorded at Durnesh Lake, Co. Donegal. Juneand September 1996.

Fauna Sampling Stations ( L.T. = light-trap) A L.T.A B IL.T.B C L.T.C D LTD jE L.T.E F L.T.F G

Porifera !

Cnidaria Cordylophora caspia a c c l + c

Turbellaria Nemertea Annelids Crustacea

Ostracoda j a Copepoda Eurytemora sp. a Cirripedia Mysidacea Neomysis integer o 18 o o ? o 3 C >100 + +

Isopoda Idotea baltica 1 Jaera nordmanni c c c Amphipoda Gammarus chevreuxi a a a a a a a c C CCC c Tanaidacea Decapoda Carcinus maenas F, 2 F, 2 F. 1

Crangon crangon 1 I Palaemonetes varians o c c 75 c 4 0 5 + 1 C Arachnids

Insects Thysanura Ephemeroptera 2

Odonata Ischnura elegans + c o c o c 1 Plecoptera + Trichoptera (cases) c Hemiptera Corixidae + c c c + 1 a a a + Callicorixa praeusta + c + + c c c + Corixa panzeri c c c + + + c + + Hesperocorixa linnaei c Arctocorisa germari + Sigara dorsalis + + + + + + S. falleni + + + S. stagnalis c + + c + + +

Coleoptera I j 1 c c + Anacaena globulus + Graptodytes granularis + _ Gyrinus aeratus +

*Helophorus brevipalpis 1

*Hydroporus angustatus j _ *H. gyllenhalli 1 + -- i - *H. incognitos -

H. memnonius + i j - j+ + j -- H. palustris + +

H. pianos j + H. pubescens +

H. striola _ + j H. umbrosus +

+ = present; o = occasional; c = common; a= abundant; F = fyke net = Station not known C

E L. W H.W.M. 0

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Fig 20.2.1Location Map of Sampling Stations in Durnesh Lake, Co. Donegal. 0

IJ J

Table 20.2.1. cont.. Fauna Recorded at Durnesh Lake, Co. Donegal.June and September 1996.

Fauna Sampling Stations ( L.T. = light-trap) A L.T.A B L.T.B C L.T.C D L.T.D E L.T.E F L.T.F G Coleoptera cont. Hygrotus impressopunctatus + + ! + -- --- r H.inaequalis _ + + *Laccophilus minutus Noterus clavicornis _ +

Diptera Chironomidae c o + a ? a >1000 Molluscs Prosobranchia Potamopyrgus antipodaru c a a c c c o

Pulmonata Lymnaea peregra + 1 0 3 0

Planorbis corneus 1 Sementina complanata + Opisthobranchia Bivalvia i Bryozoa Echinodermata Tunicata Teleostei Anguilla anguilla + F, 9 F, 6 Gasterosteus aculeatus + + + 2 + 3 0 Mugilidae F, 1 J Platichthys flesus F, 21 F. 18 F, 20 F, 1 Salmo trutta IF, 1

J

J

+ = present; o = occasional; c = common; a= abundant; F = fyke net = Station not known 1 n u

Dumesh Lough 0

results of the light-traps come closest to quantitative sampling, buteven these are affected by inter- and intra-specific relationships of the fauna andthe non-random E distributionwithin the water column. Abundance categories of present, common and abundant are purely subjective, and absolute numbers vary betweentaxa. 0 Several faunal groups were sorted and distributed to specialists. Standardkeys were used to identify remaining specimens, but many of thesewere larval or juvenile stages and difficult to identify with certainty. Some groupsrequire adult EJ males for identification and these were often not available dueto low population density and the limited number of individuals collected in thetime available (eg ,Iaera, hydrobiids). 0 All Diptera are identified to family level. All Odonata positivelyidentified were Ischnura elegans and it is assumed that early instars ofthis group were of the same t:i species.

20.2.2 Results 0

Durnesh Lough was sampled on 18.vi.96 during the first partof the survey, and 0 from 24-26.ix.96 during the more intensive survey. Positions of thesampling stations are shown in Fig. 20.2. 1. 0 Environmental Variables Station A (OS 8741 6975) was located in the northwestcorner near the outlet from the lake ( Plate 20.2.3). Water depth varied from0 - 60 cm, substrate was 0 mostly sand with stones along the shoreline.Salinityof the outflowing water measured 0 - 2%o at the time of sampling, butup to 19 %o was recorded by J. Good on 26 ix 96 following a spring tide. D Station B (OS 8723 6950) was located on the southernshore where freshwater discharges into the lake (Plate 20.2.4). Substrate consisted of sand,water depth 0 varied from 30- 60 cm and salinity measured 0 %o. Station C (OS 8781 6988) was located in the northerncorner of the lake (Plate C 20.2.5). Water depth varied from 25- 50 cm, substrate was a mixture of sand, peat, silt and stones, andsalinity measured 0 %o. Station D (OS 8767 6930) was located on the southwesternshoreline. Depth G varied from 15 - 35 cms,substrate was sand and cobbles andsalinity measured 0%0 IJ Station E (OS 8837 6920) was located on the easternshore bordered by wet grassland (Plate 20.2.6). Substrate consisted of sand,silt and peat with occasional stones. Cattle use this area and the ground was heavilypoached and manured. 0 Water depth varied from 10- 30 cms and salinity measured 0%o Station F (OS 8805 6873 ) was located at thesouthern end in an arm of the lake choked with pondweed.Water depth varied from 50 -125 cms, substrate c consisted of silty sand with soft organic mud and occasionallarge stones. Salinity measured 0%0. 0 Station G (OS G 8799 6944 was located on thenortheastern shore where a point formed by a drumlin extends into the lake. Substrate consistedlargely of cobbles of 0

4 J

Durnesh Lough

varioussizes derived from the drumlin with pockets of sand andsilt. Where depth varied from 0 - 50 cms and salinity measured 0%o.

J Fauna The species recorded at the different stations, using all samplingmethods, are listed in Table 20.2.1.Among 46 taxa listed, 43 are identified to species. Thelist comprises 3 poly-mesohaline species, 10 euryhaline, 2 oligo-mesohaline, and 27 limnic species (Table 20.2.2). Two of the species are listedas a lagoonal specialists in Britain (Davidson et al. 1991).

Most species were widely distributed in the lake, reflected theabsence of a salinity gradient and the similarity of habitats at the different stations.Beetles, however, are only recorded for A, D and E. Only Crangon andthe cryptic species Jaera nordmanni, had a more restricted distribution, the latter being confinedto the western stony shores. The most abundant species were Gammarus chevreuxiand Potamopyrgus antipodarum. Ostracods, copepods and chironomids were extremely abundant in the lighttrap at F.

No details of site locations are at present available forbeetle species marked with an asterisk.

Table 20.2.2Ecological categories of the recorded taxa in Durnesh Lough. L= lagoonal specialist according to Davidson et al. (1991)

Marine None

Poly-mesohaline Idotea baltica Crangon crangon Mugilidae

Euryhaline Cordylophora caspia Neomysis integer Jaera nordmanni Gammarus chevreuxi L Palaemonetes varians L Carcinus maenas Sigara stagnalis L Anguilla anguilla Gasterosteus aculeatus Platichthvs Jlesus

Oligo-mesohaline Ischnura elegans Potamopvrgus antipodarum

Cont....

5 u

Durnesh Lough 0

Table 20.2.2 cont. G Limnic Callicorixa praeusta Corixa panzeri E Hesperocorixa linnaei Arcocorisa germari Sigara dorsalis .S. falleni 0 Anacaena glob ulus Graptodytes granularis Gyrinus aeratus 0 Helophorus brevipalpis Hydroporus angustatus H. gyllenhalli 0 H. incognitus H. memnonius H. palustris H. planus 0 H. pubescens H. striola H. umbrosus 0 Hygrotus impressipunctatus H inaequalis Laccophilus minutus Noterus clavicornis a Lymnaea peregra Planorbis corneus Sementina complanata 0 Salmo trutta 0 20.2.3 Discussion

The assemblage typifies an isolated lagoon with restricted access forboth sea water 0 and colonists from the sea. The presence of a sluiceand a long, narrow, artificial outlet to the sea, obviously restrict the entry of marinespecies but a few manage to gain access and juvenile flounder, which presumably entered in thecurrent year, 0 were quite plentiful. The majority of the recorded species arecharacteristic of medium to low salinities and a few are normally consideredto be freshwater species. 0 The lake is notable for the abundance of Gammarus chevreuxiand the diversity of corixids (7 spp.) and beetles (13 spp.). Six of thebeetles were not recorded at any EJ other site during this survey. Trout Salmo trutta were onlyrecorded at this site and at L. Gill during the survey. 0 This was the only lagoon visited in 1996 in whichthe brackishwater hydroid Cordylophora caspia was found although the species was reported fromLady's Island Lake, Co. Wexford by Healy et al. (1982) andwas found during this survey 0 at Rostellan Lake. There are only two previous records ofGammarus chevreuxi in Ireland: a report by Spooner in the Plymouth Marine Fauna(1957) giving the locality as "NE Ireland (rarely)", and a subsequent report byPinkster (1978). The 0 species is widespread in Europe in brackish habitats and islisted as a lagoonal specialist in Britain by Davidson et al. (1991), but itwas abundant in 0%o in this 0

6 J

Durnesh Lough

lake. Costello et al. (1990) listit as a species for which Irish records require confirmation.

20.2.4 Threats

Some parts of the surrounding land are heavily grazed andfarm effluents could cause eutrophication. There is a large camp site nearby and there maybe plans to increase tourist J amenities. No other threats were apparent.

20.2.5 Evaluation

Durnesh Lough isnatural sedimentary lagoon and is therefore of international importance based on geomorphology, although its outlet is artificial. J Ornithologically, the lake holds internationally important numbers of wintering Scaup and White-fronted Geese and nationally important numbers of swans.

The lake lies behind a natural sand dune barrier butits present brackish nature may be entirely due to the presence of the artificial outlet. The aquatic faunal assemblage, which was diverse, with a highproportion of freahwater insect species but only 3 lagoonal specialists. It typifiedan isolated 7 lagoon with persistently low salinity and restricted access for bothseawater and J colonists from the sea. Seven species were not recorded at other sites. One ofthe lagoonal specialists, Gammarus chevreuxi, considered to be very rare in Ireland, wasvery abundant throughout the lake. The surrounding land is a proposed NHA (Site Code No.138). In spite of the artificial nature of the outlet, thelake and its barrier are worth conserving on geomorphological grounds and for the presence of ahealthy invertebrate community which includes an important population of a rarespecies. J The outlet channel is of interest as an example ofindustrial archaeology. Designation as a proposed SAC is recommended. J

20.2.6References and Additional Sources

Admiralty. 1995. Admiralty Tide Tables: European waters including the J Mediterranean Sea. Taunton, UK: Admiralty Hydrographic Department Barnes, R.S.K. 1989 Coastal lagoons of Britain: an overview andconservation appraisal. Biological Conservation 49, 295-3 13. Carter, R.W.G.1992Sea level changes. In: B.E. Williams (ed.) Climate Change. Studies on the implications for Ireland. Dept. of the Environment,125-171.

7 u

Durnesh Lough 0 Costello, M.J., Holmes, J.M.C., McGrath, D. and Myers, A.A. 1989.A review and catalogue of the Amphipoda (Crustacea) in Ireland. Irish Fisheries 0 Investigations Series B (Marine), 33: 3-70. Couper, A. (ed.) 1983The Times Atlas of the Oceans. Times Books Ltd. 272pp. Davidson, N.C. et al.1991. Nature conservation and estuaries in Great Britain. 0 Peterborough, Nature Conservancy Council. Delany, S.1995. I-WeBS Report 1994-1995. IWC Birdwatch Ireland. 109pp. Haughton, J.P.1957. Physiography and Climate. In: Meenan, J. & D.A. 0 Webb.(eds.)A View of Ireland. Ch. 1. The British Association forthe Advancement of Science, Dublin. 254 pp. Holmes, J.M.C. and O'Connor, J.P.1988. A portable light-trap for collecting 0 marine crustaceans. Journal of the marine biological Association of the United Kingdom 68: 23 5-23 8. Hutchinson, C. 1986. Watching birds in Ireland. Irish Wildbird Conservancy. EJ 144pp. Hutchinson, C. 1979.Ireland's wetlands and their birds. Irish Wildbird Conservancy, 201 pp. 0 Martin, A., P. Shipman, H. Brady and N. Hyde 1974National Coastline Study, Vol. 1, Bord Failte/ An Foras Forbartha. 0 Moriarty, C. 1975. The small fyke net as a samplinginstrument in eel research. EIFA/T2 3 (Suppl. 1). 507-518. Pinkster, S.1978. Amphipoda. In: Limnofauna Europea. Illies, J. (ed.) 2 ed. a Stuttgart, Fischer, 244-253. Plymouth Marine Fauna 1957. Marine Biological Association, UK. Poole, W.R. 1994. A population study of the European eel(Anguilla anguilla (L.) 0 in the Burrishoole System, Ireland, with special reference to growthand movement. Ph.D. Thesis, Dublin University. Praeger, R.L. 1934. The Botanist in Ireland. Reprinted in 1974by E.P. Publishing 0 Ltd., Dublin. 398 pp. Praeger, R.L. 1937. The Way That I Went. Hodges, Figgis& Co. Dublin. 174 pp. Rohan, P.K. 1986. The Climate of Ireland. The Stationery Office.146 pp. a Royal Irish Academy. 1979. Atlas of Ireland. Prepared under thedirection of the Irish National Committee for Geography. Royal Irish Academy, Dublin. 104 pp.. 0 Sheppard, R. 1993 Ireland's Wetland Wealth. Irish Wildbird Conservancy, 152pp 0

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20.3 VEGETATION SURVEY

Pat Hatch, Sherkin Island Co. Cork

Aims The aim of this survey is to describe the vegetationof each site in such a way as to facilitate its subsequent assessment and consideration for legal protection.

20.3.1 Site Description(Fig. 20.3. 1)

This is a large lagoon set amongst pastoral farmland onlow hills.

Swamp vegetation, often fairly extensive, is dominant in marginal areasin the southern half of the site and around freshwater inflows inthe north east and north west corners. Elsewhere, shores are more open with short rock-strewnstretches and areas of low earth cliff along the eastern shore.

Shores are more or less shallowly sloping, but narrow, withadjacent land generally rising quickly to the surrounding hills.

Freshwater inflows join the lagoon from the north east, northwest and south east. A pipe runs beneath the dunes to the north eastand joins the lagoons waters with those of the sea beyond.

7.3.2 Methods n This site was surveyed by means of transects only. Thelocality of these is shown in J Fig. 20.3.2.

Each transect ran from the aquatic zone, through adjacent marginalareas, to the adjacent habitat. Aquatic and marginal areas were sampled using quadratsor releves and the adjacent habitat described.

The position of aquatic samples, particularly their distance from theshore, was dependent on water depth and, in some cases, on thedepth of soft substrates. A transect normally extended as far into the lagoon as depthwould allow. Sample area was the area clearly visible from one point.

One sample was taken at each aquatic sampling point alongthe transect. All plant species present in the sample area were recorded. The averageheight and percentage cover of each species were estimated and recorded togetherwith the total plant, higher plant and algal cover.

At the aquatic end of each transect a grapnel wasused to attempt to locate additional species and these were recorded. Where no additional specieswere found the grapnel survey was not recorded. In some cases,the grapnel was the sole method of aquatic survey due to water depth or poorvisibility. Here, of course, the results were a species list only with no cover data.The reach of the grapnel was 10 metres.

9 d r r

go Plate 202.1View of outlet channel and pipe through the barrier ofDurnesh Lake.

nm

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Plate 2022 View of Durnesh Lake looking south along outletchannel

no 09

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MW nl Plate 2023 View of northern area of Durnesh Lake nearoutlet channel, Station A

1

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A Plate 20.2.4 View of Durnesh Lake looking southeast from barrier,Station B

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Plate 20.2.5View, of northeast corner of Durnesh Lake, Station C

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Plate -202.6View of southeast area of Dumesh Lake, Station E n u

Dowiinan-5Fecie5 codes:

Slccc - (Uc ssp -'abeYndewonfd puns - nti,-«gifes Qus -r (A - Tffkd(ctT(* fo(id

Fig. 20.3.1 Durn esh dk Co. 17o SwawF- Hi9 h Wd7er Mark

0

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0

0

0

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0

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0

0 Fig. 20.3.2 Durnesh Lake, Co. Donegal:Location of Transects

0

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0 n Durnesh Lough

At each aquatic sample point measurements were taken of salinity(using a hand refractometer) and water depth. The nature of the substrate wasalso recorded. The position of each aquatic sample was recorded as `xmetres out', meaning so many metres out from the shore. For the purposes ofthis survey, `the shore' is defined as the marginal vegetation line. This can be boththe loughward edge of a swamp and the loughward edge of saltmarsh vegetation with 50metres of bare sand between it and the waters edge at time of survey.It was felt that this location method was more accurate and made sample areas more re-locatablethan one related to, for instance, high water mark, as this isdifficult to establish at many sites.

In the marginal areas through which each transect passed, homogeneousstands of vegetation were identified and sampled using quadrats or releves. Samplearea was generally 100m2 for single species and particularly species-poor stands and16m2 for other stands. Sample shape varied according to the shapeand size of the stand. For example, many marginal stands were narrow strips. All plantspecies in the sample area, their average height and percentage cover were recorded.

Salinity and water depth were measured and recorded where appropriate.Salinity readings for marginal swamps were taken at the midway pointalong that part of the transect.

Representative examples of every marginal community encountered during the course of the survey were sampled using British National VegetationClassification (NVC) methods for the purpose of subsequent classification. This involvedthe taking of five quadrats in each community and the recordingof percentage cover (using the Domin scale) and the calculation of frequency foreach species:

Cover/Abundance Values Each species in a sample is given a percentage covervalue according to the Domin scale as follows:

Domm. 10 91-100% 9 76-90 % 8 51-75 % 7 34-50 % 6 26-33 % 5 11-25 % 4 4-10 % 3 <4 % -many individuals 2 <4 % -several individuals

1 <4 % -few individuals

Frequency Values Frequency of each species within the total number of samplesis expressed as follows:

10 Durnesh Lough 0

Frequency V 81-100% IV 61-80 % 0 III 41-60 % II 21-40 % I 1-20 %

Note: The NVC volume covering saltmarsh communities was not availableat the 0 time of this survey. Therefore, these communities have not beendetermined. Swamp communities were determined according to the NVC `Swamps and Tall Herb Fen' volume. 0

Representative examples were used as there was insufficient time tosample each community at every site where it occurred in this way.The resulting data are 0 presented in an appendix to this report.

Each aquatic and marginal transect sample is presented here intable form, with a 0 brief description covering dominant species, stand structure and physiognomy.

The locations of transects within each site were selected torepresent the degree of a variation therein. Variation in marginal zone floristics, aquatic floristics andshore and aquatic substrate were taken into account. Transects were locatedat the outlet to the sea (where present) and the major freshwater inflow(where present) as a 0 matter of course.

Adjacent habitat and land use was described in general termsand dominant species 0 recorded. a A brief site description was written for each lagoon.

Constraints 0 Time. Restrictions on the time available in which to carryout this survey had the following consequences: 0 a). The five largest lagoons were surveyed using transects onlyas there was insufficient time to carry out a full shore-based survey; b). Marginal NVC survey was carried out on representative standsonly 0 (see `Methodology').

Resources. No boats were available for survey purposes. This isone reason why 0 this is primarily a shore-based survey.

Safety. Considerations of personal safety, in view of the factthat the surveyor was 0 working alone, meant that, with one exception, no dives wereundertaken. This is the second reason for the restriction of this survey, inthe main, to the lagoon shores. 0

Identifications 0 Ruppia species were identified by Pat Hatch and by JimRyan, National Parks & Wildlife Service a

11 J

Durnesh Lough

Charophytes were identified by Pat Hatch and by Jim Ryan,NPWS

Filamentous green algae: due to the difficulty in obtaining determinations, filamentous green algae is recorded in this report as `filamentousalgae'. Larger Enteromorpha is recorded simply as `Enteromorpha'.

Other algal species were identified by Helen Fazakerley, Phycology Dept., University College Galway and Michael Guiry, Professor of Botany, University College Galway

Nomenclature

Scientific names of vascular plants in this report are inaccordance with Clapham, Tutin & Warburg, `Excursion Flora of the British Isles' (ThirdEdition). Scientific names of charophytes are according to N.F. Stewart and J.M.Church, `Red Data Books of Britain and Ireland: Stoneworts' (1992).

Evaluation

This section comprises a brief summary of the survey findingsfor each site, a grading of each site according to specified criteria and recommendationsfor further survey.

The criteria employed in the assessment and grading of eachsite are species composition, diversity and abundance, the presence ofrare species and whether or not a site is representative of a certain `type'. Bothaquatic species and marginal communities are taken into account, though particular importance is puton aquatic macrophytes. Due to the difficulties in obtaining determinations for filamentous green algae, such species have not been taken into accounthere. Sites are graded as `Valuable', `Potentially Valuable' and `Not Valuable'.

A 'Valuable ' site is one that is shown tobe of particular interest and that is considered to be worthy of conservation/protection.

A `Potentially Valuable ' site is one which thissurvey indicates may be of interest and which may prove to be valuable following furthersurvey.

A `Not Valuable ' site is one that is shownto be of little or no interest.

The fact that this is primarily a shore-basedsurvey and not a full aquatic survey (see `Constraints') makes a complete assessment of many sites impossible. Further aquatic survey of sites where recommended is to be encouraged.

n 12 U Durnesh Lough

20.3.3 Results

Site: Durnesh Lake Transect code: A

Location: Outlet to sea Sample Point: 1 Aquatic - 50m out Sample area: 16m2 4 x 4 Substrate: Sand

Depth: 60cm Salinit : 5arts p er thousand NVC communit :----- Height cm Cover Total Plant 80 Higher Plant 80

Ruis s p. 6 80

Description: Fairly dense, low growing Ruia.

Site: Durnesh Lake Transect code: A Location: Outlet to sea Sample point: 2 Marginal Sample area: 25m2 5x5 Substrate: Sand

Depth: 50cm Salinit : 5arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontaniswamp - S.lacustris ssp 0 tabernaemontani sub-community Height cm Cover 0 Total Plant 70 Higher Plant 70 0 Schoeno lectus lacustris sstabernaemontani 140 10 Ruis s p. 10 60 0

Algae 1 0 Enteromor ha 1

0 Description: Sparse S. lacustris swam extendin from about 8- 28m out from shoreline. Extensive low growing Ruia, some in flower and in fruit. Enteromor ha restrictedto free- floating Fucoid algae. 0

0

0

0

13 J

Dumesh Lough

Site: Durnesh Lake Transect code: A Location: Outlet to sea Sample point: 3 Marginal Sample area: 80m2 10x8 Substrate: Sand

J Depth: 0 - 30cm Salinit : 5arts per thousand NVC community: S20 Schoenoplectus lacustrisssp tabernaemontani swamp - S.lacustris ssp tabernaemontani sub-community Height (cm) Cover (% Total Plant 100 Hi her Plant 100

Schoeno lectus lacustris sstabernaemontani 140 90 Potamo eton ectinatus 20 10 Ruis s p. 15 1

Litorella uniflora 5 1

Algae 1

Chara canescens 6 1 Chara as era var. as era 6 < 1

Description: Tall, dense Schoeno lectusswam with P.ectinatus occurin throughout, Ruis restricted to smallareas of more open cover 70 - 80 %), Litorellaalong shoreward edge only. Sparse Chara canescens and C.as era

Site: Durnesh Lake Transect code: A Location: Outlet to sea Sample point: 4 Marginal. Sample area:l Om2 (10x 1 Substrate: Cobbles

Depth: ----- Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 5

Glaux maritima 10 5

Description: 0.5- 1 m wide strip of cobble shore with sparseGlaux.

J 14 Durnesh Lough

Site: Durnesh Lake Transect code: A Location: Outlet to sea Sample point: 5 Marginal 0 Sample area: 16m2 4x4 Substrate: Sand Depth: ----- Salinit : ----- 0 NVC communit : Undetermined Height (cm) Cover C/O Total Plant 100 0

Iris suedocorus 170 80 Fili endula ulmaria 130 10 0 A rostis stolonifera 30 10

Mentha a uatica 30 1

Potentilla anserina 10 1

Vicia cracca 40 1

Description: Tall, densely growin g Iris dominant with species-poor understore of freshwater associates on sand bank, slope c. 30 degrees, heightc. 3m..

Grading to Marram dune grasslandbarrier .

Site: Durnesh Lake Transect code: B

Location: Open shore Sample point: 1 Aquatic - 5m out- grapnel Sample area: Grapnel only Substrate: Not known

Depth: 80cm + Salinit : 5arts per thousand

NVC communit : ----- Height (cm) Cover (%)

Potamo etonectinatus Ruis s p. Chara as era var. as era

Description'.

15 Durnesh Lough

Site: Durnesh Lake Transect code: B Location: Open shore Sample point: 2 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Cobblesravel

Depth: 15 - 50cm Salinit : 5arts per thousand NVC communit :----- Height cm Cover

Total Plant 1 Higher Plant < 1 J Potamo etonectinatus 30 < 1

Algae < 1

Chara as era var. as era 10 < 1

Description: Sparse plant cover on coarse,fairly steel sloping substrate. More or less the same from 1-5m out.

Site: Durnesh Lake Transect code: B Location: Open shore Sample point: 3 Marginal Sample area:l Om2 l Ox 1 Substrate: Cobbles,ravel

Depth: 0-15cm Salini : 5arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabemaemontaniswamp -S.lacustris ssp tabemaemontam sub-community Height cm Cover Total Plant 5 Higher Plant 5

Schoeno lectus lacustris sstabernaemontani 60 < 5 Potamo etonectinatus 30 < 1 Litorella uniflora 6 < 1

Algae < 1

Chara as era var. as era <1

Description: Very sparse, low growing Schoeno lectus in 1 mstrip alonshore. Aquatic associates all sparse.

16 0

Durnesh Lough 0

Site: Durnesh Lake Transect code: B 0 Location: Open shore Sample point: 4 Marginal Sample area: lOm2 10x1 Substrate: Boulders, cobbles,ravel

Depth: ----- Salinit : -----

NVC communit : Undetermined Height cm Cover Total Plant < 1

Glaux maritima 5 < 1 Potentilla anserina 4 < 1

Description: lm strip rock shore with sparse p lant cover. Grading to Festuca rubra - Dact lislomerata grassland on 60 de gree slope to c. 5m height, with Schoenus ni ricans, Rosa im inellifolia,R. canina. Backing to Holcus lanatus - C nosaurus cristatus pasture.

Site: Durnesh Lake Transect code: C Location: Open shore Sample point:1 Aquatic - 12m out Sample area: 16m2 4x4 Substrate: Cobbles, coarseravel

Depth: 90cm Salinit : 3arts per thousand NVC communit :----- Height cm Cover Total Plant 100

Potamo eton ectinatus 80 100

Descri tion: Dense bed of tall Potamo etonectinatus.

17 Durnesh Lough

J Site: Durnesh Lake Transect code: C Location: Open shore Sample point: 2 Aquatic - 3m out Sample area: 25m2 5x5 Substrate: Cobbles, coarse J ravel Depth: 0 - 45cm Salinit : 3arts per thousand NVC communit :----- Height cm Cover %) Total Plant 5 Hi her Plant < 1

Potamo eton ectinatus 40 < 1

Algae 5

J Chara as era var. as era 8 5

Description: Sparse charo h e cover on stop substrate withscattered P.ectinatus.

Site: Durnesh Lake Transect code: C Location: Open shore Sample point: 3 Marginal Sample area: 10m2 10x1 Substrate: Boulders, cobbles,ravel

Depth: ----- Salinit: ----- NVC communit :Undetermined Height cm Cover Total Plant 10

Juncuserardii 12 5 A rostis stolonifera 10 5

Potentilla anserina 3 1 Glaux maritima 10 < 1

Substrate 90

Boulders 5 Cobbles 75 Gravel 10

Description: Sparse cover of J.erardii - A. stolonifera dominated community on stop substrate. 3m. Gradin to Schoenus ni ricans flush vegetation on c. 45degree slope to c. 6m height, with Festuca rubra, Briza media, Succisaratensis, Juncus articulatus. Backing to Lolium erenne- Holcus lanatus - C nosaurus cristatus pasture.

18 0

Durnesh Lough 0

Site: Durnesh Lake Transect code: D Location: Sparse emergent stand Sample point1 Aquatic - 50m out 0 Sample area: 16m2 4x4 Substrate: Sand

Depth: 50 cm : 3 Salinit arts per thousand a NVC communit :----- Height cm Cover Total Plant 15 0 Hi her Plant 10

Potamo etonectinatus 30 10 0 Ruis s p. 15 < 1

Algae 5 0

Chara as era var. as era 5 5 0

Description: Sparse cover of fairly low growing aquatics. 0

0

0

0

a

0

0

0

0

0

0

0

19 Dumesh Lough

Site: Durnesh Lake Transect code: D Location: Sparse emergent stand Sample point: 2 Aquatic - 25m out Sample area: 16m2 4x4 Substrate: Sand

Depth: 40 cm Salinit : 3arts per thousand NVC communit :----- Height cm C over Total Plant 60 Higher Plant 50

Potamo etonectinatus 15 50 Ruis s p. 10 < 1

Algae 10

Chara as era var. as era 5 10

Description: Fairly high cover of low growing Potamo etonectinatus with freq uent charo h e and very sparse low growing Ruia. J

J

J

20 U

Durnesh Lough 0

Site: Durnesh Lake Transect code: D 0 Location: Sparse emergent stand Sample point: 3 Aquatic - 5m out Sample area: 16m2 4x4 Substrate: Sand 0 Depth: 30 cm Salinit : 3arts per thousand NVC communit :----- Height cm Cover 0 Total Plant 60 Hi her Plant 50 0 Potamo eton ectinatus 20 50 M rio h llum s icatum 10 < 1 0 Algae 10 0 Chara as era var. as era 6 10

Description: Fairly high cover of low g rowing Potamo etonectinatus with fre uent charo h e and very sparse low growin g Mrio h llum. 0

0 Site: Durnesh Lake Transect code: D Location: Sparse emergent stand Sample point: 4 Marginal Sample area: 25m2 (5x5 Substrate: Sand

Depth: 0 - 20cm Salinit : 3arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp 0 tabernaemontam sub-community Height cm Cover Total Plant 20 0 Hi her Plant 20

Schoeno lectus lacustris sstabernaemontani 80 15 0 Potamo etonectinatus 30 5 M rio h llum s icatum 10 < 1 0

Algae < 1 0 Chara as era var. as era 6 < 1

0 Description: Open Schoeno lectus swam with sparse aquatic associates. Grazed.8m 0

0

21 Durnesh Lough J

Site: Durnesh Lake Transect code: D Location: Sparse emergent stand Sample point: 5 Marginal J Sample area: 16m2 4x4 Substrate: Not known

Depth: ----- Salinit : -----

NVC communit : Undetermined Height cm Cover Total Plant 100

Juncuserardii 15 60 A rostis stolonifera 15 50 J Scir us maritimus 25 10 Potentilla anserma 6 5 Leontodon autumnalis 15 < 1

J Description: Species-poor J.erardii - A. stolonifera community with occasional young S. maritimus shoots. Grading to Irissuedacorus - Juncus eflusus freshwater flush community, 30m. Backing c.45 de gree slope to c.6m height with Schoenusni ricans flush vegetation (as Transect Q. Backing Lolium erenne - Holcus lanatus- C nosaurus cristatus pasture. J

J

ri J

22 11 L) U

Durnesh Lough 0

0

Site: Durnesh Lake Transect code: E

Location: Schoeno lectus swam Sample point: 1 Aquatic - 50m out 0 Sample area: 16m2 4x4 Substrate: Sand Depth: 50 cm Salinit 4arts per thousand 0 NVC communit :----- Height cm Cover Total Plant 35 0 Higher Plant 30

Potamo etonectinatus 25 25 0 Ruis s p. 10 5 M rio h llum s icatum 10 < 1 0

Algae 5 0 Chara as era var. as era 6 5

0 Description: Patch cover of dominant Potamo eton ectinatus with lowgrowing associates. 0

Site: Durnesh Lake Transect code: E 0 Location: Schoeno lectus swam Sample point: 2 Aquatic - 25m out Sample area: 16m2 (4x4 Substrate: Sand 0 De the 50 cm Salinit : 4arts per thousand NVC communit :----- Height cm Cover (% 0 Total Plant 60 Higher Plant 50 0 Potamo etonectinatus 30 50 Ruis s p. 10 < 1 0

Algae 10 0 Chara as era var. as era 6 10

0 Description: Potamo etonectinatus dominant, its cover increasing as Ruis cover decreases. 0

0 23 Durnesh Lough

Site: Durnesh Lake Transect code: E Location: Schoeno lectus swam Sample point: 3 Aquatic - 5m out Sample area: 16m2 4x4 Substrate: Sand

Depth: 50 cm Salinit : 4arts p er thousand NVC communit :----- Height cm Cover Total Plant 75 Higher Plant 70

M Potamo eton ectinatus 30 70 U Algae 5

Chara as era var. as era 6 5

Description: Potamo eton cover increasing. Ruis now absent. Char o h e cover more or less constant.

Site: Durnesh Lake Transect code: E n Location: Schoeno lectus swam Sample point: 4 Marginal u Sample area: 100m2 10x10 Substrate: Sand Depth: 50 cm Salinit : 4arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp tabernaemontani sub-community Height cm Cover Total Plant 100

Schoeno lectus lacustris ss tabernaemontani 180 90 Potamo etonectinatus 50 30

J Description- Tall dense single species S. lacustris swam for 30m,with frequent Potamo eton ectinatus the only aquatic associate.

24 U

Durnesh Lough

Site: Durnesh Lake Transect code: E Location: Schoeno lectus swam Sample point: 5 Marginal Sample area: 100m2 10x10 Substrate: Sand

Depth: 50 cm Salinit : 4arts p er thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp- S.lacustris ssp tabernaemontani sub-community Height cm Cover (% Total Plant 30 Higher Plant 25

Schoeno lectus lacustris ss tabernaemontani 180 10 Potamo eton ectinatus 60 15

Algae 5

Chara as era var. as era 6 < 5 Chara his ida var. major 30 < 5

J

Description: Open Schoeno lectus swam for 20m, with P.ectinatus sparse but dominant in aquatic zone over associated charo hes.

Site: Durnesh Lake Transect code: E Location: Schoeno lectus swam Sample point: 6 Marginal Sample area: 100m2 10x10 Substrate: Sand

Depth: 50 cm Salinit : 4arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontaniswamp -S.lacustris ssp tabernaemontani sub-community Height cm Cover (%) Total Plant 100

Schoeno lectus lacustris sstabernaemontani 180 90 Potamo etonectinatus 50 30

Description, Tall dense single species Schoeno lectus swam for 10mwit h P.ectinatus the only aquatic associate.

25 J

Durnesh Lough J

Site: Durnesh Lake Transect code: E Location: Schoeno lectus swam Sample point: 7 Marginal Sam le area: 100m2 10x10 Substrate:Silt (de-oxygenated)

Depth: 20 cm Salinit : 3arts per thousand NVC community: S20 Schoenoplectus lacustris ssp tabernaemontani swamp -Agrostis stoloru'fera sub-community Height cm Cover Total Plant 100

Schoeno lectus lacustris sstabernaemontani 180 100 A rostis stolonifera 30 20 J Description: Tall dense S. lacustris swam for 50m with frequentA rostis. 7 t__1

J Site: Durnesh Lake Transect code: E Location: Schoeno lectus swam Sample point: 8 Marginal Sample area: 16m2 8x2 Substrate: Not known

J Depth: ----- Salinit : ----- NVC communit :Undetermined Height cm Cover Total Plant 100

Juncuserardii 15 50 A rostis stolonifera 15 50 Potentilla anserina 6 10

7 Description: Dense cover of species-poor Juncuserardii - A. stolonifera community. 3m. lJ Grading to Schoenus ni ricans flush vegetation (as Transect Q,10m on c.15 degree slope. Backing to line of trees 10m width on c.40 degreeslope to c.5m bank height - Prunus s inosa, Cratae us monona, Salix cinerea.

Backing Lolium erenne - Holcus lanatus - C nosaurus cristatus pasture.

7 Lj

n 26 UI u

Durnesh Lough G

0

Site: Durnesh Lake Transect code: F Location: Tha swam Sampleoint: I Aquatic - 2m out - grapnel 0 Sample area: Grapnel only Substrate:Silt

Depth: 80 cm + : 2 Salinit arts per thousand 0 NVC communit : ----- Height cm Cover 0 Potamo eton ectinatus Ruis s p. a Enteromor ha a Description: a

0 Site: Durnesh Transect code: F Location: Tha swam Sample oint: 2 Marginal 0 Sample area: 100m2 10x10 Substrate: Silt (de-oxygenated)

Depth: 80 cm Salinit : 2arts per thousand NVC communit :S 12 T ha latifolia swam - Tha latifolia sub-communit 0 Hei ht cm Cover Total Plant 100 0 T ha latifolia 200 100 0

Description: Tall dense single species Tha swamp. 20m. 0

E

0

0

0

a 27 J

Dumesh Lough J

Site: Durnesh Lake Transect code: F Location: T ha swam Sample oint: 3 Marginal Sample area: 100m2 10x10 Substrate: Silt (de-oxygenated)

Depth: 0 - 50 cm Salinit : 0arts per thousand NVC communit :S 12 Tha latifolia swam - Alisma lanta o-a uatica sub-community Height cm Cover Total Plant 100

T ha latifolia 200 100 Alisma lanta o-a uatica 70 < 1 Lemna minor < 1 J Description- Tall dense Tha swam with sp arse freshwater associates. 10m J Backing to Lolium erenne - Holcus lanatus - C nosauruscristatus grassland, 15m on c.15 degree slope. Grazed. Backing line of trees, 10m on c.35 degree slope toc.6m height - Co lus avellana Prunus s inosa, Crataes monona. Backing Lolium - Holcus - C nosaurus pasture.

Site: Durnesh Lake Transect code: G Location: Freshwater inflow Sample point:1 Aquatic - 2m out - grapnel Sample area: Grapnel only Substrate: Silt

Depth: 70 cm + Salinit : 0arts per thousand J NVC communit :----- Height cm Cover

Potamo eton ectinatus Potamo eton c.f obtusifolius M rio h llum s icatum Callitriche sta nalis

Enteromor ha

7 lJ Description'.

28 U

Durnesh Lough 0

0

Site: Durnesh Lake Transect code: G Location: Freshwater inflow Sample point: 2 Marginal 0 Sample area: 100m2 10x10 Substrate: Silt

Depth: 30 - 70 cm Salinit : 0arts per thousand NVC communit :S4 Phra mites australis swam - Phra mites australls sub-community 0 Height cm Cover Total Plant 100 0

Phra mites australis 270 100 Lemna minor 30 0

Description: Dense Phra mites swam for 30m with Lemna coverincreasing to landward. 0

0

0 Site: Durnesh Lake Transect code: G Location: Freshwater inflow Sample point: 3 Marginal 0 Sample area: 100m2l Ox 10 Substrate: Silt

Depth: 0 - 20cm Salinit : 0arts per thousand NVC communit :S4 Phra mites australis swam - Galium alustre sub-community c Height cm Cover Total Plant

Phra mites australis 270 100 Nasturtium officinale 15 60 0 Lemna minor 30 M osotis scoioides 10 5 Galium alustre 20 < 1 0 E uisetum fluviatile 50 < 1 0 Description: Dense Phra mites swam with Roria dominant amon st species- poor understore of freshwater species. 15m. C

C

0

0 29 J

Durnesh Lough J

Site: Durnesh Lake Transect code: G Location: Freshwater inflow Sample point: 4 Marginal Sample area: 100m2 10x10 Substrate:

Depth: 0 cm Salinit : -----

NVC communit : S4 Phra mites australis swam- Galiumalustre sub-community Height cm Cover J Total Plant 100

Phra mites australis 180 80 E uisetum fluviatile 40 75 Nasturtium officinale 15 5 Fili endula ulmaria 120 5 Galium alustre 30 < 1 L hrum salicaria 60 < 1 Mentha a uatica 20 < 1 A rostis stolonifera 20 < 1

Description: Reduced Phra mites cover with E uisetum dominant amongsts pecies-poor fen vegetation. 20m. Grading to willow can strip 30m width - Salix cinereadominant, average height c. 5m, with epiphytic mosses and lichens. E uisetumfluviatile dominant below. Backing to public road.

J

J

J 30 u

Durnesh Lough 0 20.3.4 Evaluation 0 `Valuable'

This large site was surveyed by transects only. Therefore, theinformation available 0 upon which to make this assessment is limited compared tomost other sites. Seven transects were carried out. 0 Chara canescens was found growing fairly sparsely in the vicinityof the outlet pipe. This rare charophyte was previously recorded from six Irish sitessince 1970. Its presence at Durnesh is reason enough to regard the siteas valuable. 0

Chara aspera var. aspera was found at five transect sites,indicating a wide distribution. 0

Chara hispida var. major was found growing with C.aspera var.aspera in an area of C open water in a Schoenoplectus swamp.

Ruppia was found at five transect sites, which indicatesa wide distribution here. 0 Dense patches occur near the outlet pipe. Elsewhere Ruppia wassparse or found by grapnel survey only. It is notable that both R.cirrhosaand R.maritima occur here. 0

Potamogeton pectinatus occurred in all seven transects. Dense stands ofthis species were found at two of these sites. 0

Litorella uniflora was found at the two northernmost transect sites.Myriophyllum spicatum occurred at two sites in the southern half ofthe lake. 0

Potamogeton c.f. obtusifolius and Callitriche stagnalis occurred with P.pectinatus and Myriophyllum spicatum at the major freshwater inflow. 0

Marginal vegetation shows little variation. Phragmites and Schoenoplectusswamps are extensive in places and Typha latifolia is locally dominantin the southern half of 0 the site, indicating the lower salinities here. The surveyedopen shores were dominated by a Juncus gerardii- Agrostis stolonifera community. 0 Salinity levels were low at time of survey, varying from0 parts per thousand at the freshwater inflow in the south to 5 partsper thousand around the outlet pipe in the north.

Durnesh Lake is regarded as a good representative ofa low salinity lagoon, with 0 high species diversity and a species composition and distribution whichreflect the spatial variation in conditions from freshwater to brackish. 0 Further survey is recommended. C

0 31 J

J Durnesh Lough

20.4 ECOTONAL COLEOPTERA

J.A. Good Ph.D MIEEM FRES J Terrascope Environmental Consultancy, Riverstick, Co. Cork

20.4.1 Site Description

Large coastal brackish lake in drumlin landscape, with sand dunebarrier with artificial J outflow/inflow channel, and small sandflat between beach and dunes. Extensive Schoenoplectus lacustris stands (Plate 1) and large areas of marshand reedbeds on lakeshore.

Subsites (see 20.4. 1)

1. Schoenus margin (G 871696) Due to high water levels at the time of sampling,an upper shore zone above the flooded area was sampled, characterised by Schoenus nigricans, Filipendula ulmeria, Parnassius palustris, Briza media, Centuarea nigra, etc. It is assumed thatwater margin species migrated into this flooded grassland zone with rising water. Salinityof flood water was 5%o (I 5 viii 1996).

2. Iris/grass mar in (G 872697) J Iris/grass on sandy loam grading into Schoenoplectus lacustris in floodedstanding water (similar to above), behind dune barrier. After spring tide, salinitywas 19%o (26 ix 1996).

3. Sandflat (M 254117) Unvegetated aerobic sandflat beside outflow pool on beachside of sanddune barrier.

20.4.2 Methods

Site Rating using Indicator Species Species rarity or community typicality are the most frequently usedcriteria for rating sites for their biological conservation value. The approach inthis Coleoptera survey is to use selected species to indicate that sitesare ecologically well- developed with relatively undisturbed natural processes still operating. In particular, it is assumed that this is shown by the presenceof assemblages of species which have specialised habitat requirements for habitat features created by physical processes (e.g. aerobic sandflat, washed peat slopes) or biotic responses(algal growth, Scirpus monoculture) to these processes.

As a consequence, the rating is intended to be ofmore general ecological value (i.e. indicating ecotonal soil biota), than purely indicating the presence ofrare beetles. Indeed, in one case, a rare species has been excludedas an indicator because it lacks a specific requirement for habitats created in the lagoonsites.

Therefore, species were selected as indicators of conservation value if:(1) they have a restricted habitat preference to a specific type of microhabitat associatedwith the lagoon

32 0

0

0

0

0

0

p i 0 H 0 loom 0

0

0

0

D

0

Fig. 20.4.1 Map of sampling sites (Carabidae and Staphylinidae) atDurnesh Lake, Co_ Donegal. a

I- Pitfall traps, S-vac 2 - Pitfall traps 0 3 - Ground search

0

0 J

J Durnesh Lough

margins; and, (2) they are reported in the literature asbeing local or rare, from which it is assumed that they are less likely to survive in historicallydegraded ecosystems.

J Interpretation of Indicator Species Sites were not rated simply on the number of indicatorspecies, but the following considerations were also taken into account: (1) Whether the indicatorspecies was likely to originate from the habitat associated with the lagoonor a surrounding habitat (see Lough Aconeera, for instance), taking into account thenumber of individuals of the species present (singletons are often vagrant); (2)The habitat requirements of the non-indicator species, if they indicated an anthropogenically disturbed habitat (see Bridge Lough, for instance) ; (3) Whetherthe habitat feature might be uniquely created by the lagoonal conditions (see LoughTanai, Section 14, for instance).

Sites were rated into four categories of conservation value: (1)No recorded value; (2) low value; (3) average value; (4) exceptional value. Itwould be difficult to defend a categorization of sites into any finer categories thanthis (see Foster et al. (1992), for instance). Sites were not rated of average valueif there were less than two indicator species present (see argument in Good and Speight1992).

J Limitations of Ratings The site ratings are based on recorded data using standardisedsampling methods. The ratings refer to the terrestrial/ecotonal soil assemblages, and donot represent the aquatic/ecotonal assemblages (e.g. aquatic Coleoptera, etc.) or herbivorous assemblages (e.g. Lepidoptera). Different indicator species are likely to occurin spring, but it is assumed that the relative number ofindicator species would not differ significantly. The number of indicator species and their relativeinterpretation is based on a reasonably standard sampling effort at eachsite. Greater sampling effort will probably result in higher numbers of indicator species,but it is assumed that this will not affect the relative rating of sites.

Sampling Strategy At each site representative marginal areas were sampled, including vegetationdominated by Scirpus maritimus, Juncus maritimus, Juncus gerardi and grasses, as wellas bare or poorly-vegetated areas of sand, silt or peat. Particular emphasis wasgiven to habitat associated with the sedimentary barrier and areas of highest salinity,since much of the habitat associated with freshwater inflows to the interior of thelagoons would contain a soil fauna not dependent on coastal lagoons.

Sampling Techniques The sampling methods used are listed in Table 20.4.1. Foreach site, a Stilil® BR 400 suction apparatus, mounted on the operator's back, was used. Thismachine (referred to hereafter as 'S-vac' to distinguish it from the 'D-vac' suctionsampler) has a suction pipe of 58 mm diameter (0.0026 m2 surface area). Six subsamples (transects)of 100 x 1.5 sec. 'sucks' per subsample were taken at each site, resulting ina total area of 1.56 m2 covered. Because the hand-held pipe was shaken when the apex ofthe pipe was in the vegetation, a J

33 u

Durnesh Lough 0

larger area (c. 2 m2) was effectively sampled. Sets ofsix pitfall traps with undiluted 0 ethylene glycol (commercial anti-freeze) preservative were also dug into thesoil at each site. Because many of the species expected to occur insuch a habitat are adapted to climbing during flooding, these traps were fitted with funnels cutand shaped (with tape) 0 from the same type of plastic cups that were usedfor the traps themselves.

0

TABLE 20.4.1. Details of sampling methods. 0

0 Method Details No. replicates Sampling period, etc. per unit sample a Suction sampler Stihl suction sampler 6 100 x 1.5 sec 0.026 m2 Pitfall traps Plastic cups with ethylene 6 30 days glycol preservative and 0 plastic funnels; collars used where cattle/horses occur Cobble samples Cobbles turned 0.5 - 2 m 30 0 from water margin Flotation Samples taken where 24 5 cm x 10 cm x 5 cm 0 depth burrow casts observed; agitated soil floated in water 0 Ground search Search of bare soil (< 50% 1 1 hour vegetation cover) during warm weather without rain 0

Habitat features associated with the sedimentary barrier, such as shinglecobbles on finer 0 substrate, bare or poorly vegetated sand, and peat cliffs, werealso sampled if they occurred to a sufficient extent (> several m2) at the site.Sampling involved a fixed time ground search (1 hour) during warm dry weather, or a fixednumber of cobbles turned (n = 30) or 0 cliff sods (8 subsamples of 5 x 5 x 10cm) extracted by flotation in a bucket of sea or brackish water. Sampling was carried out during late summer and early autumn (late July to early October), with some sites visited in June. This was unavoidable, anddue to time constraints associated with the survey, but it is assumed that thespecies occurring during this period 0 are representative of the sites, even if spring species maybe absent.

hariety of sampling techniques 0 Several techniques will always give a more robust picture ofthe fauna of a site, because any weather- or site-affected bias in one technique willbe compensated by other sampling methods. Some sites did not possess suitable habitat(peat cliffs, 0 bare sand, cobbles on sediment, etc.) for flotation, ground searchor cobble search. This is regarded as an absence of habitat, rather thanan unavailable sampling 0

34 Durnesh Lough opportunity. That some sites, therefore, had more sampling effort usingthese additional methods is not regarded as sampling bias, but agenuine reflection of the habitat diversity of the site.

Flooding of pitfall traps Flooding is a problem for sampling lagoon sites using pitfalltraps, especially as it is difficult to visit sites twice between spring tides to placeand lift traps. Altogether, about 80 traps were flooded due to water level changes;these were not included in the survey. However, this was planned for, and three sets(6 traps each) were placed at all sites (four sets at some sites), ofwhich two were sorted. There was only one site (Aughinish which has a spring/neap water levelvariation of >I m) where flooding limited trap results to only one set.

Weather conditions and sampling The suction sampler is very efficient in grass, rush andsedge swards which are dry, but useless if they are even slightly wet, because thesampling pipe and net becomes wet. The priority for sampling therefore was to visit sitesin response to dry weather forecasts, thus all sites were successfully sampled using thistechnique. However, as a result of this strategy, the period thatpitfall traps were placed varied from site to site. This is not regarded as biasingresults to any great extent, however, as much of the trap sample appears to beobtained in the first two weeks.

Quality control. identification Voucher specimens of indicator species have been retained and willbe deposited in the National Museum of Ireland, and specimens of many of theother species have been retained in the author's collection.

References Foster, G.N., Nelson, B.H., Bilton, D.T., Lott, D.A., Merritt, R.,Weyl, R.S. and Eyre, M.D. (1992) A classification and evaluation of Irish water beetleassemblages. Aquat. Conserv.: Mar. Freslnv. Ecosyst. 2: 185-208. Good, J.A. and Speight, M.C.D. (1991) Sites of international andnational importance for invertebrate fauna - a definition proposed for use in site surveys. Bull. Ir. biogeog. Soc. 14: 48-53.

Methods used at this site

Carabidae and Staphylimdae (Coleoptera) were recorded from :

(1) Schoenus margin - S-vac suction sampler (26 ix 1996), c.2 m2- (2) Schoenus margin - 6 plastic pitfall traps with funnels andethylene glycol preservative (15 viii - 26 ix 1996); (3) Sandflat - flotation (c. 0.09 m2 x 5 cm depth,15 vi 1996); (4) Sandflat - 1 h ground search (15 vi 1996); (4) Iris /grass margin - 6 pitfall traps (26 ix -17 x 1996).

Species were selected as indicators of conservation value if: (1)they have a restricted habitat preference to a specific type of microhabitat associated withthe lagoon margins;

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Durnesh Lough 0

and, (2) they are reported in the literature as beinglocal or rare, from which it is assumed that they are less likely to survive in historically degradedecosystems. 0

0 20.4.3 Results

Eight species of carabid and twenty-nine species of staphylinid wererecorded, three species 0 of which are regarded as indicator species (Table 20.4.2).

The separation of the two species of Diglotta has heretoforebeen confused by incorrect 0 species concepts (J. A. Good, in preparation). Diglotta submarina mayyet prove to be an indicator species for this site, but its distributional status isnot clear, so it has been omitted. 0

Myllaena infuscata is generally local in Europe and occurs inmarshy meadows, ditches, alder carr, etc. (Horion 1967), rather than on lake shores.While it can be regarded as 0 stenotopic (e.g. Koch 1989), it could occur inland of DurneshLake, and is not likely to be dependant on shore habitats created by coastal processes. It hasnot therefore been selected as an indicator species. 0

There are few Irish records of Philonthus furcifer, a speciesnot recorded from Great Britain (Lott and Foster 1990, Lott and Bilton 1991). Itis rare in Europe, and occurs on 0 marshy shores including those on sea coasts (Horion 1967).

There are three pevious Irish records of Stenus lustrator (Anderson1984), which appears 0 to be local in Europe (Horion 1963). The species istyrphophilous (associated with peat), but also occurs on marshy shores and flood meadows, accordingto Koch (1989). The Irish 0 records are from bogs (Anderson 1984), and the species wasalso recorded at Faranamanagh Lake and Lough Aconeera in this survey, both ofwhich posess peat margins or adjacent bog. 0

Schistoglossa gemina is widespread but local in Great Britain (Hymanand Parsons 1994), and widespread but rare in Central Europe and Scandanavia (Benickand Lohse 1974, Palm 0 1970). It has been recorded previously from Ireland (O'Mahony 1929).The habitat of the species is marshy lake shores, wet meadows and marshes includingwet ditches in sand 0 dunes (Koch 1989, Hyman and Parsons 1994). 0

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a 36 J Durnesh Lough

J

TABLE 20.4.2.Carabidae and Staphylinidae (Coleoptera) recorded from Durnesh Lake. Nomenclature follows Lucht (1987) and Lohse & Lucht (1989), with the exception of Diglotta which follows Good (in preparation).

Species No. individuals

Carabidae

Agonum fuliginosum (Panz.) 4 Agonum pelidnum (Payk.) 7 Bembidion mannerheimi Sahib. 8 Bembidion pallidipenne (Ill.) I 1 Dromius linearis (01.) 2 Leistus terminatus (Hellw.) I Pterostichus niger (Schall.) 11 Pterostichus nigrita (Payk.) I

Staphylinidae

Anotylus maritimus Thoms. Anotylus rugosus (F.) I J Atheta amplicollis (Mull. Rey) I Atheta vestita (Grav.) 3 Bledius fergussoni Joy 18 Bledius subniger Schneid. 3

Carpelimus corticinus (Grav.) 1 Cypha laeviuscula (Mannh.) 4 Diglotta submarina (Fairm. Lab.) I Drusilla canaliculata (F.) 2

Euaesthetus ruficapillus Bois. Lac. 1 Gyrohypnus angustatus (Steph.) 2

A yllaena infuscata Kr. 1 Ocvpus olens (Mull.) 8 Oxvpoda elongatula Aubd 2 Philonthus furcifer Renk.2 Indicator species Phvtosus balticus Kr. I

Quedius fuliginosus (Grav.) 1

Quedius nigriceps Kr. I

Schistoglossa genuna (Er.) 1 Indicator species

Sepeclophilus nigripennis (Steph.) I Staphylinus dimidiaticornis Gemm. 1 .Stenus brunnipes Steph. 2 Stenus fuscipes Grav. 6 Stenus juno (Payk.) 2 Stenus lustrator Er. 2 Indicator species Stenus nitens Steph. 4 Stenus ossium Steph. I Tachinus signatus Grav. 3

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Durnesh Lough 0

20.4.4 Evaluation 0 Of average conservation value for terrestrial ecotonal community. (Rating categories : None, low, average, exceptional] 0 Scientific Argument for Rating E The presence of three indicator species (Table 20.4.2) indicatesan ecologically well- developed system. However, all indicator species plusa further one which was excluded as inappropriate can breed in freshwater wetlands, and theiroccurrence at this site may be due 0 to the large acreage of reedbeds and marshes adjoining thelake (e.g. towards Rossnowlagh). 0

20.4.5 References 0 Anderson, R. (1984) Staphylinidae (Coleoptera) in Ireland- 3: Stemnae. Ir. Nat. J. 21: 242-251. 0 Benick, G. and Lohse, G.A. (1974) Staphylinidae 11 (Aleocharinae, Callicerini).In: Freude, H., Harde, K. W. and Lohse, G.A. (eds). Die KaferMitteleuropas. 5. Goecke & Evers, Krefeld. pp. 72-220. 0 Horion, A. (1963) Faunistik der Mitteleuropdischen Kdfer. IX. Staphylinidae: Micropeplinae bis Euaesthetinae. Feyel, Uberlingen-Bodensee. Horion, A. (1967) Faunistik der Mitteleuropdischen Kdfer. XI. Staphylinidae: 0 Habrocerinae bis Aleocharinae (Ohne Subtribus Athetae). Feyel, Oberlingen- Bodensee. Hyman, P. S. and Parsons, M.S. (1994) A review ofthe scarce and theatened Coleoptera of 0 Great Britain. Part 2. UK Nature Conservation Series No. 12,Joint Committee for Nature Conservation, Peterborough. Koch, K. (1989) Die Kdfer Mitteleuropas. Okologie. 1. Goecke &Evers, Krefeld. 0 Lohse, G.A. and Lucht, W.H. (1989) Die Kdfer Mitteleuropas.12. 1. Supplementband mil Katalogteil. Goecke & Evers, Krefeld. Lott, D.A. and Bilton, D.T. (1991) Records of Coleoptera fromIrish wetland sites in 1989. 0 Bull. Ir. biogeog. Soc. 14: 60-72. Lott, D.A. and Foster, G.N. (1990) Records of terrestrial Coleopterafrom wetland sites in 1987, including Stenus glabellus Thomson (Staphylinidae)new to the British Isles. 0 Ir. Nat. J. 23: 280-282. Lucht, W.H. (1987) Die Kdfer Mitteleuropas. Katalog. Goecke & Evers,Krefeld. 0 O'Mahony, E. (1929) Coleoptera. In: Praeger, R.L. (ed.) Reporton recent additions to the Irish fauna and flora. Proc. R. Ir. Acad. 39(B): 22-36. Palm, T. (1970) Skalbaggar, Coleoptera. Kortvingar: Staphylinidae. Underfam. 0 Aleocharinae(Atheta). Svensk Insektfauna no. 52: 117-296.

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Plate 1 Schoenoplectus lacustris stands at Durnesh Lake, Co. Donegal a ran

do so Durnesh Lough

20.5 SUMMARY AND EVALUATION

Durnesh Lough is a large (c. 70 ha), natural sedimentarylagoon and is therefore of international importance based the Habitats Directive although its outletis artificial.

The lough lies within a proposed NHA (Site 138).

Ornithologically, the lake at times holds internationally important numbers of wintering Scaup and White-fronted Geese and nationally important numbers of swans.

The following table shows the conservation value of the lakebased on the four main criteria of the survey. The values given are modifiedfrom the original rating system which varied for each criterion

Geomorphology High Aquatic Fauna High Vegetation High Ecotonal Coleoptera Average

Geomorphology

Durnesh Lough is a large natural sedimentary lagoon, separated fromthe sea by a sand dune barrier and by poorly drained farmland fronted bycobble barriers. It lies J in an area of drumlins which underlie the barrier. Seawaterenters the lough through an artificial sluiced channel, mainly during spring tides, but thesalinity in the lough did not exceed 5%o during the survey except near theoutlet. The lake is shallow and the bed mainly sandy.

As a good example of a natural sedimentary lagoon witha dune barrier, the lake is rated as of high conservation value in spite of itsartificial outlet.

Aquatic Fauna

Among 46 taxa recorded, 43 were identified to species andthree are lagoonal specialists. The aquatic faunal assemblage included a high proportion offreshwater insect species. Corixids (7 spp.) and beetles (13 spp.) wereparticularly diverse. The fauna typified an isolated lagoon with persistently low salinityand restricted access for both seawater and colonists from the sea.

The loughis notable for the abundance of Gammarus chevreuxi for whichthere are only two previous records in Ireland. The species iswidespread in Europe in brackish habitats and is listed as a lagoonal specialist inBritain, but it was abundant in 0%o in this lake. Trout, Salmo trutta,were only recorded at this site and at L.

39 u

Durnesh Lough 0

Gill during the survey. This was also the only lagoonvisited in 1996 in which the 0 brackishwater hydroid Cordylophora caspia was found although the species has been reported from Lady's Island Lake and was found duringthis survey at Rostellan Lake. 0 The aquatic fauna is rated as of high conservation valuefor its high diversity of insects, the presence of seven species not recorded elsewhere, andthe abundance of 0 Gammarus chevreuxi.

Vegetation 0

This large site was surveyed by transects only. Therefore, theinformation available upon which to make this assessment is limited compared withmost other sites. 0

Ruppia was widely distributed but sparse with dense patches nearthe outlet pipe only. It is notable that both R.. cirrhosa and R..maritima occurred here. E Potamogeton pectinatus also occurred widely, sometimes in dense stands. 0 Chara canescens was found growing fairly sparsely in the vicinityof the outlet pipe. This rare charophyte was previously recorded from six Irishsites since 1970. Its presence at Durnesh is reason enough to regard thesite as valuable. Chara 0 aspera var. aspera was found at five transect sites, indicatinga wide distribution. Chara hispida var. major was found growing with C.aspera var.aspera in an area of open water in a Schoenoplectus swamp. 0

Potamogeton c.f obtusifolius and Callitriche stagnalis occurred with P. pectinatus and Myriophyllum spicatum at the major freshwater inflow. Litorella uniflorawas 0 found at the two northernmost transect sites. Myriophyllum spicatum occurredat two sites in the southern half of the lake. 0 Marginal vegetation showed little variation. Phragmites and Schoenoplectus swamps were extensive in places and Typha latifolia was locallydominant in the southern half of the site, indicating the lower salinities here.The surveyed open 0 shores were dominated by a Juncus gerardii - Agrostis stoloniferacommunity.

Durnesh Lough is regarded as a good representative of alow salinity lagoon, with 0 high species diversity and a species composition and distribution whichreflect the spatial variation in conditions from freshwater to brackish. For thesereasons, and E the presence of Chara canescens, the site is rated asof high conservation value. Further survey is recommended. 0 Ecotonal Coleoptera

Eight species of carabid and twenty-nine species of staphylinid wererecorded, three species 0 of which are regarded as indicator species.

The separation of the two species of Diglotta has heretoforebeen confused by incorrect 0 species concepts. Diglotta submarina may yet prove to be anindicator species for this site, but its distributional status is not clear, so it hasbeen omitted. 0

40 0 Durnesh Lough

Myllaena infuscata is generally local in Europe and occurs inmarshy meadows, ditches, alder carr, etc. rather than on lake shores. While itcan be regarded as stenotopic, it could occur inland of Durnesh Lake, and is not likely tobe dependent on shore habitats created by coastal processes. It has not therefore been selected asan indicator species.

There are few Irish records of Philonthus furcifer, a speciesnot recorded from Great Britain It is rare in Europe, and occurs on marshyshores including those on sea coasts.

There are three previous Irish records of Stenus lustrator whichappears to be local in Europe. The species is tyrphophilous (associated with peat), but alsooccurs on marshy shores and flood meadows. The Irish records are from bogsand the species was also recorded at Faranamanagh Lake and Lough Aconeera in this survey,both of which possess peat margins or adjacent bog. J Schistoglossa gemina is widespread but local in Great Britain andwidespread but rare in Central Europe and Scandinavia It has been recordedpreviously from Ireland The habitat of the species is marshy lake shores,wet meadows and marshes including wet ditches in sand dunes.

The presence of three indicator species indicates an ecologically well-developedsystem. However, all indicator species plus a further one which wasexcluded as inappropriate can breed in freshwater wetlands, and their occurrence at this sitemay be due to the large acreage of reedbeds and marshes adjoining the lake (e.g. towardsRossnowlagh). The site is therefore rated as of average conservation value for ectonal Coleoptera.

Summary

Durnesh Lough is a large, natural sedimentary lagoon, separated fromthe sea by a sand dune barrier, but its present brackish nature may beentirely due to the presence of the artificial outlet.

The aquatic fauna typified a low salinity lagoon with littlecontact with the sea. The assemblage is rated highly for its high diversity of insects,the presence of seven species not recorded elsewhere during the survey, and the abundanceof the rare amphipod Gammarus chevreuxi. 7 The lake holds internationally important numbers of wintering Scaup andWhite- Li fronted Geese and nationally important numbers of swans.

The vegetation is regarded as being representative of a lowsalinity lagoon, with high species diversity and a species composition and distribution whichreflect the n spatial variation in conditions from freshwater to brackish. For thesereasons, and the presence of Chara canescens, the site is rated highly. J The presence of three indicator species of ecotonal Coleoptera indicatesan ecologically well-developed system. All can, however, breed in freshwater wetlands thereforethe site is rated as of high, but not exceptional, conservation value.

41 Durncsh Lough a

Overall, Durnesh Lough is rated as of high conservation valueas large 0 sedimentary lagoon containing a high diversity of aquatic fauna and vegetation and some rare species. Its designation as a proposedSAC is recommended. 0

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