The Natural History of Chessel Bay Local Nature Reserve, © Southampton Wildlife Link Chaimlan: Julian Crel110na B.Sc.. C. BioI.. F.R.E.S.. PGc.E. Supported by: Report First published January 1993 Produced by the Southampton Wildlife Link British Gas­ Southern The Southampton Wildlife Link is a voluntary body which meets monthly at the Civic Centre. It consists of representatives from the chiefecological and natural history groups in the area. Those groups are:

English Nature Southampton Schools Conservation Corps Southampton Natural History Society Southampton Commons and Parks Protection Society & IOW Wildlife Trust Royal Society for the Protection of Birds British Trust fOf Ornithology Broadlands Valley Conservation Group British Butterfly Conservation Society Hawthoms Wildlife Association Sholing Valleys Study Centre Association Friends of Shirley Pond ENVIRONMENT

Correspondence to the Hon. Sec. Mrs. P. Loxton. 3 Canton Street. Southampton

Also available is a Slide Pack. This consists ofapproximately 30 colour transparencies with notes describing the ecology of Chessel Bay CONSCIOUS

1 1 A Report on the Natural History of Chessel Bay Local Nature Reserve Southampton .

by

The Southampton Wildlife Link 1993 CONTENTS

Litter...... Aims . . 3 21 Introduction . 4 Bait digging . 21 Woodland . 5 Seaweed collection . 21 Pressures on the Woodland .. 6 Trawling . 21 Mudflats . 8 Planting in woodland . 21 Id' IM .. Macroalgae . 8 n ustna onttonng .. 21 Microalgae. . . 8 Promote responsibility-education . 21 Invertebrates . 9 Scientific monitoring . 22 Birds . 11 Appendix 1: Flora ofChessel Bay . 23 Shingle . 13 Appendix 2: Insects . 26 Appendix 3: Vertebrates . 28 Appendix 4: Mudflat Community . 29 Marsh ...... 16 Pressures on the Bay Shoreline .. 17 Appendix 5: Birds found around Chessel Bay 30 Development & Reclamation . 18 Results ofBird Counts . 31 Wave action and wash from boats . 18 Litter . 19 Bait digging . 19 Bird disturbance .. 19 Fishing from the shore . 20 Commercial trawling . 20 Oystercatcher Seaweed collections .. 20 Ships going aground on mud . 20 Nutrients and fertilisers . 20 Spillage from industry along river. . 20 Recommendations . 21 Formation ofbye laws . 21 Oppose any planning permission . 21 Encroachment by land reclamation . 21

SQuthampton Wddhfe Link 2 AIMS OF THIS REPORT

The principle aim of this report is to highlight the wildlife communities that exist in Southampton's first Local Nature Reserve and express their importance in the region. This inevitably raises the problem of pressures that are currently imposed on the organisms that inhabit the Reserve and we make recommendations that will help to maintain the Bay as a quiet backwater along the River Itchen.

This report is intended to assist:-

• Teachers - to help as resource material

• City Planners - when making future decisions

• The Public - to increase their interest in the Bay

Southampton Wildlife Link 3 INTRODUCTION

12% of the city of Southampton comprises river and tidal area. September 1991 the area was officially opened by Southampton They are as such an essential habitat. The River Itchen is of City Council as a Local Nature Reserve and is now a Site of international importance and used by Butcher (1933) as a type Special Scientific Interest (SSSI) along with the rest of the river of chalk. Within the City boundary the river has extensive upper Solent region. areas of intertidal mudflats but only one part is unaffected by seawalls and/or industrialisation. This single stretch of estuarine The Nature Reserve is now managed by a Management seashore and adjoining land has been referred to as Chessel Bay Committee which meets quarterly. Representatives come from since before the 18th century, when the Chessel House was various interested parties including the City Council (landscape built. It is located to the south ofNortham Bridge where the R. architect and ecologist), Southampton Wildlife Link, Itchen meanders to produce a very wide loop and is situated on Southampton Schools Conservation Corps, English Nature and the depositing side. Thus, not only sediment and shingle collects the Headmaster ofBitterne Manor Primary School. but also man-made debris most ofwhich is non-biodegradable.

The Reserve area is approximately 14 hectares and has been The principle ecological habitats within the reserve are protected from development in the past by the railway line that runs to the back ofthe Reserve and isolating it from the Chessel • Woodland estate. At either end of the Reserve there are industrial estates • Mudflat which, through land reclamation, have steadily encroached the • Shingle mudflats. These, along with the railway line, mark the • Saltmarsh boundaries of the Reserve. Not only is it the only semi-natural shore remaining on the R. Itchen but also because within its confines is the point where the Common Reed (Phragmites communis) merges into Cord Grass (Spartina sp.). This highlights the region at which freshwater changes into a saline habitat. Its importance lies not just as a local reserve but as part of a national picture. It represents a vital feeding and over­ wintering site for migrating waders and other seabirds. In

Southampton Wildlife Lmk 4 WOODLAND

Maps produced over the centuries have shown the extent of So, although tiny and isolated, the woodland at Chessel Bay is woodland to the north and east of Southampton, extending part of the original ancient woodland of several centuries ago, from West End down to the edge of at West Wood. and this is borne out by the quantity and variety of species Today the ancient woodland is fragmented, leaving small found there. remnants such as exist at Frog's Copse and Hum Hole. The woodland is ofoak/birch type, growing on a sandy/clay soil In 1910, the Chessel Estate (which, until 1923, was part of and the dominant tree is Pedunculate Oak (Quercus robur). The Bitterne Manor in the Diocese of Winchester) stretched from recent establishment ofbirch is by natural succession. The piece the River Itchen to Bitterne Road (Lance's Hill) and Peartree ofwoodland nearest to Quayside Road was used for allotments Avenue down to Chine Avenue in the area of what was once during the war and the oak trees here have regenerated. Since "The Copse". Chessel House was positioned where Nos 31 ­ that time, other oaks have been planted. This part of the 39 Chessel Avenue now exist. The woodland of the estate, woodland is more open with other species of trees present fragmented from ancient forest, grew on the sand and clay of including plum, apple and cherry. The plum trees have become the Bracklesham Beds. established from the days ofthe allotments as have possibly the apple and cherry, although both of these latter are associated A map of 1826 shows woodland stretching from Bitterne Road with oak woodland. to the Chessel Bay shore but the building of the Southampton to rail link severed this woodland, leaving the The presence of Cow-wheat (Melampyrum pratense) and the narrow strip oftrees along the Bay shore. diversity of other plant species such as Bluebell (Hyacinthoides non-scriptlls) and the Great Willowherb (Epilobium hirsutum), Part of this ancient woodland at Hum Hole ceased to be a Wood Spurge (Euphorbia amygdaloides) and the closely functioning ecosystem with the building of the Bitterne by-pass related trees, Whitebeam (Sorbus aria) and Mountain Ash and was reduced to virtually park status. This woodland was (Sorblls allcllparia), indicate that this wood was part of an the nearest habitat to Chessel Bay from which colonisation ancient woodland. could take place; with the demise of Hum Hole, dispersal of insects and seeds has slowed down to Chessel Bay. The ground flora has been eroded by the excessive use of bicycles amongst the trees. Many plants are known to have been present in quantity but now are only represented by small

Southampton Wildlife Link 5 samples such as the Bluebell, Wood Sage (Teucrium PRESSURES ON THE WOODLAND scorodonia) and Wood Anemone (Anemo11e 11emorosa). It is The site lies close to a residential part of Southampton. hoped that these and others will recolonise in greater densities Although the mudland benefits from being relatively when remedial work to the banks has been carried out. inaccessible, the linear woodland receives high usage from local people in relation to its small size. This has resulted in Erosion of soil under the mature trees has reduced the a variety ofproblems: quantities ofleaflitter and associated invertebrates. In the dense cover of the scrub, decaying organic matter is protected and • Vandalism and fire. Since the introduction of the path and insects are prolific in the late spring and early summer. directed access the incidence of vandalism seems to have Ichneumon wasps are abundant including the largest species subsided somewhat although some damage has occurred to which hunt the larvae ofbutterflies and moths. The rotting fruit the wooden rails ofthe observation platform. Bonfires have from the plum trees attract a wide range of insects and several for many years caused damage to trees, particularly those large, uncommon hoverflies, e.g. Volucella zOllaria, take refuge next to the shingle habitat. Drift wood was collected, piled here. Their larvae are parasitic on wasps and hornets. Wood up below the base of the trees and set alight. With the boring beetles disperse by flight and these are seen during early formation of the Nature Reserve this has become a rare summer evenings flying along the railway and around the wood. sight. The regular litter picks organised by the Management The Stag Beetle (Lucallus cervus) is now a declining species Committtee remove much of the combustible materials and and limited to southern England but is fairly abundant, most thus reduces this hazard yet further. years, in the Bitterne area. The larvae feed for up to four years inside a variety oftrees and it is certain that the trees ofChessel • Increasing access and footpaths. The wooded region has for Bay are important in this respect. many years been dissected by a multitude ofpaths which has led to excessive erosion ofthe soil beneath the oaks and on Roe deer are frequent visitors to the Bay, using the railway line the, now, gravel banks. Within the first year of the Nature as a passageway between habitats. The quiet wetland and scrub Reserve designation the Management Committee arranged area between Gainsford Road and the railway is often used as a the closure ofthe side paths and the production of a single, feeding place for several mammals including deer and foxes. main path through the wood. This is gravelled to reduce wear. The desired effect seems to have worked and access has been directed to limit the trampling. It is surprising by how much an area ofhabitat is reduced when constructing a path and this one was reduced to the minimum possible. It

Southampton Wildlife Lmk 6 has been suggested that this could be widened to create a Emeromorpha imestillalis cycleway. This would not only cause a devastating effect on the wetJand but also remove twice the area of the existing path from the habitat.

• Erosion of woodland banks. At the edge of the woodland, the land drops away on to the strandline of the seashore. Erosion on the upper areas was due, in the past, to young people swinging on ropes fixed around the upper branches of the trees. The lower parts of the slopes are almost certainly being eroded through action of the tides. Severe undercutting ofseveral mature trees has taken place.

• Railway. The railway in the past has probably been a saving Estuarine fucoids Diatoms grace for the Bay helping to isolate it from development. The present threat is from the cutting back of trees and vegetation within 25 feet of the track.

Fig. 1 Seaweeds from '!le mud and shingle Top. two green algal species, ElIleromorpha intestinalis & U/va lac!uca (the Sea Lettuce) Bottom left. a brown alga, f'1fClIS sp. Bottom right: the diatom Pleuroslgma (magnified 400x)

Southamplvn W,ld" re Lonk 7 MUDFLATS depositing seashore, are the most prolific in life because oftheir property ofretaining water. Diatoms live within the surface film Macro Algae In late spring and summer the casual visitor obtaining sunlight and they photosynthesise. This is the basis of might be excused for thinking the upper mudflats are green one ofthe food webs within the mudflat community. meadows. The river water contains nitrates, principally derived from fertiliser sources. Coupled with other eutrophication Diatoms are dependent on nutrients, such as silica, arriving with nutrients this leads to the growth of extensive swards of green the tide. Coupled with warmer conditions and increased light algae, primarily E11leromorpha intestinalis and some Sea there is a bloom ofdiatoms in the spring. After a slight dip there Lettuce (Ulva lactllca). The former is able to regulate the ionic is usually a second but smaller rise in numbers in late August concentration of its cells under variable salinities and and September. Twenty-one different species of diatoms have consequently does well in the bay. This mass of green algae is so far been found although several genera dominate these food for the small pulmonate mollusc Hydrobia ulvae which is blooms e.g. Pleurosigma, Navicula and Nitzschia. These tend extremely abundant during some seasons. to be quite mobile species, moving around within the watery spaces, coming to the surface to reach the light. The former two Other than a few species of brown algae, associated more with genera also release mucilage to reduce desiccation. The sliding the shingle because of their requirement of a hard substrate for diatom is a particularly spectacular species to be found in the attachment, there are very few macro-algae species. mud. A careful study of the diatom species could reveal information on possible pollutants in the bay. Micro Algae The principle algal species are represented by the microscopic diatoms which are seasonally very abundant. Microscopic algae are not the only vital producers to maintain These minute plant-like organisms live within the spaces the communities within Chessel Bay. Bacteria are essential. At between the silt and mud particles; as these inorganic grains are high tide the shallow waters within the wide sweep of the bay so small the spaces are equally microscopic. Thus at low water deposit fine particles of organic matter. This is derived from they tend to hold the moisture and drainage is minimal. This is both freshwater and marine sources. Along with faecal material the opposite to sand which tends to dry out as the tide recedes. produced by the animals buried in the mud, the organic matter On a sunny day the mud is very reflective at Chessel Bay feeds the bacteria. The origin of some of the organic matter is confirming the presence of water. Human activity centres from the marshes around the bay, particularly the Phragmites around sandy beaches because of its cleanliness. Dry sand does and Spartina. These plants have stems and leaves which are not encourage life. Mudflats, out ofall the various types of high in sclerenchyma. These highly-fibrous cells reduce damage

Southampton Wlidhf. Lmk 8 to themselves caused by the scouring effect of the water but in in the form of birds which are resident in the Bay and others turn are virtually inedible by the animals living there. It is only which visit. with the gradual breakdown by the mudflat micro-organisms that they slowly release their stored nutrients and become Four forms of energy are therefore at the basis of any food edible. This is just one of the many examples in the Bay where webs present in the bay. one small habitat depends on another. In this way the Bay marshes help to supply the mud with decaying particles of • macro algae organic matter (termed detritus) which in turn will feed the • micro algae invertebrates. • bacteria • detritus Below the surface, the mud changes colour from brown to black. The latter indicates the sulphide layer which develops The feeding relationships that associate with these sources are because of the lack of oxygen. The sheltered conditions which therefore complex and vary dramatically with the seasons. The give rise to Chessel Bay do not provide for a high level of community ofanimals living within the mud in Chessel Bay is a dissolved oxygen, more typical of rough water. As a distinct community ofendemic littoral invertebrates which is consequence the diffusion of oxygen from the surface into the unaffected by the problems which occur with the Solent e.g. hot mud is minimal. Invertebrates living within the mud therefore water and chemical effluents. The species diversity is not require some form of contact with the surface, such as a particularly high, essentially because ofthe twice daily variation burrow, to obtain oxygen from the air. in salinity. Organisms that possess mechanisms that can cope with their bodies being inundated by freshwater have therefore Invertebrates Many people see the mudflats as the least become established. The crab Carcinus maenas is the only interesting of the habitats and commenting on the "smelly" British species capable ofpumping excess water out ofthe body nature of the mud. But it is the very fact that it is "dirty" with whilst the ragworm Nereis diversicolor is able to tolerate, for a organic matter that makes this ecologically so important number of hours, the presence of water as it bloats the cells. compared to clean sand which is little short of being a desert. Once the tide brings back seawater the freshwater leaves the The apparent lack of life on the surface ofthe mudflat is due to cells. With such adaptations, species that can become the burrowing nature of the invertebrates, avoiding the established in such inhospitable conditions then have minimal desiccating conditions when the tide recedes. Most of the competition and their density will be high. The tiny snail animals spend their entire life buried, never venturing above the Hydrobia will, by autumn, reach densities of around half a surface. The only sign of life beneath is the wealth of predators million per metre square. It is at this time that they migrate and

Southampton Wildlife Lmk 9 disperse across the mud by floating on mucus rafts as the tide Digging (other activities discussed in the section on pressures) comes in. This results in a large build up of Hydrobm around will of course affect other burrowing invertebrates, especially the high-water mark but does enable the snail to maintain its those with poor mobility. The Sand Gaper, Mya arenaria, is a numbers across the Bay large bivalve mollusc that has a thin shell and lives in a mix'ture of mud and sand. Like all bivalves it has two tubes or siphons The variation in salinity along the Bay produces a mild example that connect the animal with the surface. One brings in water of zonation in several shrimp-like crustaceans, particularly ladened with detritus and oxygen, whilst the other discharges Gammartls dl/eheni and G. zaddachi, each having its own waste. The siphons of Mya are fused together in a thick degree of tolerance to freshwater. These smaller crustaceans, muscular extension from the body. As the animal grows the along with the crabs, scuttle across the mud at high tide, siphon becomes longer and the body goes deeper into the mud. sheltering under the wreckage, flotsam and weed when the flats Bivalves are wholly dependent on the surface for all of their are uncovered. needs and any disturbance in the mud will reduce that contact. Mya is unable to reburrow itself if exposed by bait digging and Corophium vO/lllator is a near relative ofGammarlls but lives in will be picked off by birds. Likewise, if it is buried by such a small U-shaped burrow in the mud, where it feeds on the digging it will be unable to re-establish itself and will asphyxiate bacteria and detritus. When the mud is uncovered at low tide in the deoxygenated mud. they can be seen crawling over the mud surface and leaving a trail behind. They pull themselves along by their very long The two bivalves, Peppery Furrow Shell, Scrobicularia plana, antennae, as the legs are used for drawing water into the and the Baltic Tellin, Macoma balthica, have a well developed burrow. Some years the numbers of these in estuaries can reach muscular foot and separate siphons. These allow them the very high densities. This has not be seen in recent years at chance to re-establish their position in the mud as long as they Chessel Bay, as requires sheltered and relatively undisturbed are not picked offby predators before they can burrow. mud. Living within the top few centimetres of the mud, it is very susceptible to bait digging. Corophium is one of the prime The ragworm, Nereis dilJersicolor, thrives in the type of invertebrates which links the bacteria/detritus with the wading conditions that occur in Chessel Bay. It spawns along the south birds such as the Redshank. Another isopod crustacean is coast during February. Around this time the bodies of the Cyathllra carlllata, rather more cylindrical in shape than organism are very vulnerable to disturbance. The females Corophium. Unfortunately this rarer species has not been release their eggs by the disintegration of the body wall and as a reported seen in the bay within the last five years and may have consequence, die shortly after. Prior to this both sexes are very disappeared through some heavy bait digging seasons. fragile and disturbance to the mud could cause premature

S~uthamp\'m WoIJI,r, I.mk 10 rupturing resulting in infertile eggs and dead adults. In addition beneath the surface. The choice of food depends very much on to this, unlike most marine animals which have a planktonic the length of the bill and, to a lesser extent, the legs. The larva, the young stay within mud of the adult burrow where invertebrates live at different depths and so the length ofthe bill they develop. Disturbance of mud will further disrupt the determines the depth to which the bird can reach into the mud ragworm life cycle. and collect prey. The Purple Sandpiper that rarely visits the Bay may even plunge the head into the mud. Fig. 2 (overleaf) There are animals that move with the tide, such as the illustrates the range of bill sizes and the types offood present in swimming crustaceans. Opossum shrimps move on to the Bay the mud. This variation in the length of bill reduces possible at high tide to feed. These attract fish which, in turn, draws the competition between the waders. Some, like the Redshank, attention ofcormorants. have an average size bill which permits access to a more varied diet. In addition, Redshank selection depends on temperature: it switches from Corophium to Macoma and Nereis below scc. Birds These are the most recognised of the animals which The end of the winter is when prey is at its least dense but at its are found in Chessel Bay and were one of the reasons for the maximum size. Waders feed, throughout the year, at night as desigantion of Local Nature Reserve status. The two principle well as by day, their feeding rhythm governed by the tides. groups of birds to be seen are those which are residents in the Night feeding uses tactile senses. The bill is very sensitive and area and those on passage migration. The latter use the Bay as a those which are very long, e.g. Curlew, have a prehensile tip stopping-off post when migrating North-South in autumn and which opens under the mud. spring. It is an essential stage in the refuelling of their energy reserves by spending a period of time feeding on the wealth of Gulls, particularly the Black-headed Gull, may roost in large invertebrates living in the mud. This applies mainly to the numbers along the shoreline. Their principle breeding site is at wading birds such as Dunlin which arrive in small flocks. It Needs Ore, on the entrance to the . Like could be compared to a motorway service station en route rush-hour traffic they can be seen moving up the along the M6 except the number of these natural staging posts river in large numbers soon after dawn and follow the river back is steadily becoming fewer as the land is infilled. to the sea just before dusk.

Waders like the Curlew and Redshank are residents to the Kingfishers are seen hunting along the shoreline in the autumn region and can be seen feeding at low tide on most days during when the migrants arrive e.g. Brent Geese. These feed through the year. The waders receive their name by the fact that they the winter on the green algae, Enferomorpha and Ulva, which move around in the mud searching for invertebrates buried grow on the mud surface in the summer months.

Southampton Wildlife Link 11 godwit sander1ing curlew redshank knot ringed plover

Corophium 5

Tellina ID

Scrobicularia

l 15 e -(') '::"""; )." 3

Nereis Arenicola

Mya

Fig. 2 A comparison of different wading bird bills with potential prey items in the mud

Southampton Wildlife Link 12 SHINGLE Gravels and pebbles are limited to the upper shore and These brown algae, growing up to a third of a metre in length strandline areas. Here the spaces between the stones have not have a far from ideal habitat in which to live. They are limited been filled with sediment and small animals can gain some near the upper shore by the desiccation and lower down by the protection. Most protection, however, is afforded by the larger dominance of the mud which covers the shingle. Deposition of algal species such as the Bladderwrack (Fucus vesiculosus). silts on the fronds will also cause a limited light intensity, This species is very widespread on British seashores and is used reducing photosynthesis and further restricting growth. as a type indicator species. It is a very adaptable seaweed, being able to tolerate a wide variation in environmental stress e.g. These clumps of seaweed are a vital micro-habitat along the turbid and brackish water. Under the latter condition the fronds upper shore as they provide a safe haven for a number of become curled and with fewer bladders. It can also hybridise important crustaceans. The older, and therefore larger, with the, truly, brackish alga, the Horned Wrack (Fucus Common Shore Crab (Cardnus maenas) for example scurry ceranoides). as the name suggests, the ends of the brown, between the fronds. The smaller individuals gain some photosynthetic fronds are branched into a pair of horn-like protection, even though the herons have been seen to turn over processes. This seaweed is found along the Solent but typical the fronds in search of the softer young. These crabs, unlike examples are not seen at Chessel Bay. Possible hybrids are other British species, have the ability of regulating their water present. content using a gland at the base of their antenna. In this way they can cope with the low salinity present around Chessel Bay To make identification ofthese brown algae even more complex caused by the freshwater of the R. Itchen. They are an is the further hybridisation with a third upper shore seaweed, important scavenger of the habitat and will feed on virtually the Spiral Wrack (Fuells spiralis), which has the added anything, dead or alive. An adaptation that helps them in this advantage of being more tolerant to desiccation than the other existence is their ability to breath oxygen from the air as well as two species. Unlike true plants, all three seaweeds do not that dissolved in the water. Hence, they are active even at low possess roots and therefore require a hard substrate on to which tide when most other animals are seeking protection from the they can attach their holdfast. this is a round disc of cells which drying effect. The crab is an intermediate in the food webs that in these conditions are fairly weak attachments. It is the larger exist here, linking the smaller invertebrates to the predatory pebbles amongst the shingle that can therefore provide a gulls and Heron. suitable substrate.

Southampton W,ldlife Lmk 13 Gammarids Ligia oceanica Sandhoppers (Orchestia gamerella) can reach very high densities under the protective fronds ofthe seaweeds. Flattened from side to side they either swim off sideways when disturbed or can jump free of possible predators. These are the principle prey ofthe Turnstone, a black and white bird which occasionally visits the bay from Weston Shore where it is more abundant. The Sea Slater (Ligia oceanica) is a crustacean that also reaches a high density but is limited to the strandline. They look like giant woodlice but unlike these counterparts, they are predators not scavengers. They live amongst the litter and plant debris washed in by the tide but will leave this under the cover Estuarine erabs Mierofauna of night, to move down on to the upper shore as the tide recedes.

Fig. 3 Animals of the mudflats and shingle Top left: A sandhopper (Gammams sp.) with, top right, the Sea Slater (Ligia oceanica) found on the upper shore under debris. Bottom left: the common estuarine crab (Carcinus maenas) Bottom right: the shell ofthe microscopic Foraminifera; the amoeba-like animal lives inside. (magnified 100x) Brent Goose

Southampton Wildlife Link 14 CARNIVOROUS INSECTS e 9 Sal(lula

LEAF EATING lINSECTS

DETRITUS AND SAC rERIA/Flln\jlls \ I / [ROOTED SALT ·MARSH PLANTS I

Fig 5. A simplified food web of salt marsh

--_. ~_.-J. FURROW SHELL TELL~ti BALTIC_ MICRO­ CRUSTACEANS .. ---_.-

[ PROTOZOA I I

IDIATOMS I IDETRITUS AND BACTERIA I

Fig. 4 A simplified food web

Southampton Wildlife Link 15 MARSH extensive root systems of this grass normally provide sufficient The saltmarsh within the Bay is the smallest habitat area and anchorage in the depositing silts to build up extensive beds of perhaps the most sensitive to change. However, it is the only marsh. Then, through a process of ecological succession, other vegetation of its type in the confines of Southampton. The communities of vegetation become established in the significant aspect of this marshland is that it marks the increasingly stable conditions. Within Chessel Bay the point of transitional stage where Spartina gives way to Phragmiles in Spartina colonisation is on the river bend where the mudflats the River Itchen. As the seawater from the Solent is are probably at their most vulnerable to water movement and progressively diluted by the freshwater from the river a series of the deposition of silt is transitory. Over a year there is a brackish zones are produced along the estuary. These are not substantial change in the levels of accretion and movement in static and fluctuate hourly according to the state ofthe tide. For the small developing, water run-offchannels. This instability has example, the less dense river water will float above the more caused some problem to the Spartina in maintaining any degree dense salt water as the tide moves up the estuary. The overall of community and the number of individual plants varies from picture is one ofvarying salinities and this salt factor segregates year to year. Where the Spartina, in the past, has achieved the the vegetation so that at the Northam end the dominant marsh greatest growth is around the stable area at the end of Hazel species is the Common Reed (Phragmites) and at the seaward Road. Illegal dumping has all but wiped out this community. It end, Cord Grass (S'partina). is here that the saltmarsh community developed most fully with Sea Aster(Aster tripolium), Common Saltmarsh Grass The reedbeds, such as those at Redbridge on the R. Test, are (Puccinella maritima) and the Orache (Atriplex hastata). part of the Lower Nature Reserve and are Seeds from these dicotyledonous plants have established a substantially greater in area than those at Chessel. The limited number of individuals along the stone causeway, next to the reedbed at Chessel Bay maintains a relative paucity of animal railway line. species. For example, it is too small an area to be useful for breeding birds, such as reed warbler, not least of all because of Overall, the marsh within Chessel Bay is very limited. It is, the problem of disturbance from the public. Sedges and rushes however, important for the maintenance of the Bay that the grow around this marsh area increasing the diversity ofspecies. marsh continues. The leaves from these grasses, particularly Spartina, are tough to withstand the scouring effects ofthe silty On the seaward end of the Bay the vegetation becomes more tide and when alive offer little nutrient value to the animals. It is typical of saltmarsh with the colonisation by the Spartina. The during the autumn and winter that the dietary significance

Southampton Wildlife Link 16 develops. The micro-organisms across the mud slowly rot the improvement in the area of marsh would improve and stabilise material down, producing essential nutrients that enter the the community. faecal soup. It is through the decomposition of the saltmarsh plants that rich foodstuffs then become available to the wealth ofinvertebrates which, in their turn, become the dinner table for PRESSURES ON THE BAY SHORELINE the seabirds, particularly the winter migratory birds. Situated within the confines of one of the largest cities in A number ofalgal species become wrapped around the stems of southern England it is inevitable that a large number of human the marsh vegetation e.g. Enteromorpha and Viva. This can activities will affect the Nature Reserve. It is essential that these lead to a better stability of the silts and give some minor should be identified and any adverse actions stopped to preserve protection from the wave action. A few algae, particularly the the habitats. In recent years the following have been perceived microscopic forms, live specifically here and are only limited by as the main pressures on Chessel Bay. the amount oflight passing through the tall plants. Vlothrix can become very prolific, reaching its peak in spring before it is • Development in any form within the Bay shaded out. • Wave action caused by the prevailing winds. • Wash from boats Animal life within the marsh habitat is very limited, mainly due • Litter to the paucity of consumable vegetation. The essential factor • Bait digging that the plants provide is one of shelter. Animals like the • Boats going aground on the mud Saltmarsh bug (Saldllla palllstris) used to be seen scurrying • Fishing from the shore across the mud in search of insects, caught on the exposed • Commercial trawling surface, and then running back amongst the grasses. With the • Encroachment by land reclamation and dumping decline in the marsh at the Woolston end these have now • Seaweed collections disappeared. Colonisation is principally by the crustaceans such • Nutrients and fertilisers from river as sandhoppers and sea slaters which move between the • Spillage from industry along the river strandline and upper shore scavenging in search offood. When Chessel Bay received its reserve status Bay the City Generally, the habitat has become too sparse to support the Council arranged for a Management Committee to be usual community of animals found on southern marshes. Any established with the objectives of handling the problems of the Bay as well as being in an advisory position to the Council. The

Southampton Wildlife Lmk 17 pressures, outlined above and identified from various sources cut through the Reserve drastically reducing the area of are discussed at the quarterly meetings. The particular problems natural habitat and causing untold disturbance to feeding are outlined below. birds.

1. Development & encroachment by land reclamation All habitats have a minimum area below which the balance This century there has been extensive in-fil1ing of the is lost and the community can no longer maintain itself This mudland at Chessel Bay, both from the Hazel Road and has already been displayed with the problems facing the Bitterne Manor Industrial Estates. Even during 1992 the sea saltmarsh. Any further reduction and there will be a wal1 in the latter area has been extended. Infilling is significant decline in the species diversity. It would singularly the prime activity that has robbed the UK of its certainly lose the variety of invertebrates that would then natural mud and saltmarsh. With the designation of the restrict the bird and fish populations. Nature Reserve and SSSI status this should theoretical1y cease. However, il1egal dumping at the end of Hazel Road continues to cause concern about the survival of what 2. Wave action & wash from boats remains of the saltmarsh. It was the dumping over the last Reduction in the marsh, particularly the Phragmites decade that caused this to decline. reedbed, has varied considerably over the last decade and loss has been attributed to water disturbance around the Development does not just refer to the erection of buildings root systems. With the dislodgement of silts and muds from but to the creation ofroads and pavements. Chessel Bay has these roots the stability has been lost and the plants died. been the subject of applications for such development. As The cause of the wave action may be due to the swash part of the recently completed management plan a footpath created by the boats as they pass although this seems to be has been established through the woodland, based on the fairly negligible. Large boats move slowly and even at high original path. This then allowed the various side routes to be tide the waters are shal10w preventing all but the smallest closed, thus increasing the amount of natural acreage. Any boats to come close enough to the shore. further path development would be seen as detrimental to the Reserve. A cycleway was proposed some years ago, The most likely cause is the natural wave action that occurs including the development of a causeway across the mud, in the spring and autumn during gale force conditions. At and the threat is stil1 present. This was put forward as part this time the wave action can be seen to be quite severe for of a general cycle route from Mansbridge through to an inland waterway such as the R. Itchen. Woolston. The proposed route from Northam Bridge would

Southampton Wildlife Link 18 3. Litter At times the litter problem along the strandline can be seen Furrow Shell (Scrobicularia plana), is a fairly active animal as a major problem. The source of the litter has been with the ability to reburrow once disturbed. Their densities attributed to several sources but the bulk is most certainly have decline in recent years but not so disastrously as the from boats and probably arrives on the incoming tide from Sand Gaper (Mya arenaria). This is a species that goes the Solent. deeper with age such that an older individual once uncovered cannot reburrow and dies. The main problem with litter is the aesthetic one. Certain items of litter, especially wood, acts as a protective agent 5. Bird disturbance both for invertebrates and to the plants. In the latter case The Bay is an important feeding post for migratory birds some litter around the base of the Phragmites does afford across Southern England as well as for the resident some protection from wave action. However it will cut back population. Waders feeding at low tide will be affected by on light reaching the algae and diatoms, reducing human interference. Most people remain in the path region photosynthesis. not venturing out on to the soft mud. Bait diggers are the most serious threat causing such disturbance. This is a 4. Bait digging particular problem in the winter months when the greatest During late autumn and late winter the Bay looks like a concentration ofwaders arrive. battlefield with large craters pitting the surface of the mudland. There may only be four to six diggers but in some 6. Fishing from the shore cases they are professional bait diggers who sell on the As yet this is not seen as a major problem particularly as worms to shops in the area. They are known to cause most anglers are responsible individuals. No record has been considerable problems on other seashores in the Solent made of broken line being found and with the replacement region e.g. Hillhead. The turn over ofmud not only removes of lead weights with suitable alternatives the only possible the ragworm but seriously damages the habitat structure. problem is one of disturbance. There have been reports of The ragworms form an important intermediary food item in some anglers lighting small bonfires. the reserve foodweb. Recovery of ragworm populations back to the original density has been shown, in other estuaries, to take several years. Of equal concern is reduction in population densities of other invertebrates affected by the digging disturbance. The bivalve, Peppery

Southampton Wlldltfe Link 19 7. Commercial trawlint:: The wealth of invertebrate animal life encourages a large of tugs but produced considerable movement and population of flatfish e.g. flounder. This has lead to a disturbance ofmud. steady increase in commercial trawling. Although it is illegal to trawl this far up the R. Itchen, upwards of six separate 10. Nutrients and fertilisers from river trawlers have been seen at anyone time on the mudflats at Nitrates, dissolved in the river water, vary across the high water. As well as the removal of these mobile animals seasons but have reached levels of 300 ppm during 1992. the main concern is the amount of damage that these trawls This, along with other minerals, increases the amount of make on the mud. The principle food source to the animals certain algae and diatoms. The affect of this is unclear in the mud is the faecal soup which forms on the surface. although at some periods of the year the Biochemical This is removed with the trawling as well as several inches Oxygen Demand is high. Organic matter and detritus arrives depth of mud with the accompanying animals. Long ruts on the mud from both sea and river environments. From the criss-crossing the surface can be clearly seen at low water. latter the material can often be identified because of the The marks left by a week's trawling are still identifiable short time period between removal and deposition; almost a month later. decomposition has rarely started let alone completed. Much of this is derived from broken fragments of aquatic 8. Seaweed collections Ranunculus species, (Water Crowfoot). Gardeners have removed the brown algae from the shore for many years, for fertilising their allotments off Athelstan 11. Spillage from industry along the river Road. Although this does not seem to be done by more than Saltmarshes and mudflats have been affected by oil and a few people the amount is significant as there is a limited other spillages around the Solent region. Although Chessel population density in the first place. Removal of this micro­ Bay is well clear of the major industrial areas, minor habitat reduces the micro-communities dependent on the problems could occur from small businesses in the form of protection and food. light oils and fuel.

9. Ships going aground on the mud Several times a year ships of around 2000 tons fail to negotiate the long bend in the river at Chessel Bay and as a consequence run aground on the lower shore. On one occasion during 1992 the ship was removed with the help

Southampton Wildlife Link 20 RECOMMENDATIONS • Seaweed collections • Formation of Bye Laws Bye laws help to stop bait digging it should include all Bye laws could ban the destructive bait digging that occurs. organisms, including the removal of seaweed. At the present time there is no legal way of stopping the practise or the removal of any of the organisms. Possibly, • Trawling bye-laws could prevent trail bikes from using the area The Port Authorities must continue to stop such illegal although this problem appears to have been eradicated by activities and infringement should involve prosecution. the erection offencing around the entrance. • Planting in woodland to reduce bank erosion • Oppose any Planning Permission for the Bay The erosion of the banks in the wooded areas is severe. We must ensure that no development, particularly the Work is necessary to restore the correct topsoil and soil proposed cycleway, is allowed. In this way no more natural structure. A possible way of stabilising the area would be to area will be reduced. place logs at intervals down the slope to reduce soil creep. This could be given a chance to become established but • Encroachment by land reclamation and dumping planting this with seedlings, selected from the more lush Vigilance needs to be exercised to identify possible illegal areas of the woodland, would help the colonisation as well tipping as maintaining the local gene pool.

• Litter • Industrial monitoring This is a never-ending problem but kept in check by regular By monitoring the various industries and any potential litter picks organised by the council and Southampton outfall along the banks ofthe River Itchen the possibility of Schools Conservation Corps. The Harbour Master is any toxic spillage would be reduced. responsible for the prevention ofsea and river borne litter. • Promote responsibility - educational use • Bait digging Through education the public, particularly children, can be This must be outlawed or stopped. The erection of signs made aware of the ecological importance of the site. would help in this matter. Bitteme Manor Middle School is involved with the Management Committee but other schools should be targeted. The Southampton Wildlife Link have produced a

Southampton Wildlife Lmk 21 slide pack, with educational material and notes, to help teachers and other interested groups interpret the ecology.

• Scientific monitoring The pressures on the Bay that have already been identified should be carefully monitored along with potentially new ones. Surveys, possibly as part oflocal schools field study in Key Stage 4, could continue to monitor the abundance of and diversity ofthe organisms. This is particularly important with regard to the mudflat community. However, before any such surveys commence, English Nature should first be consulted.

The visiting waders are of international importance and must be monitored with regular counts to establish any fluctuations in density. Records must be maintained and use could be made of the City Council computer database although Societies and Groups within the Link already have well organised schemes ofmonitoring.

Southampton Wildlife Lmk 22 APPENDIX 1: FLORA OF CHESSEL BAY Capsella bursa-pastorlis Shepherd's Purse Cardamine flexuosa Wood Bittercress Carex acutiformis Lesser Pond sedge Acer campestre Field Maple Carex otrubae False Fox Sedge Acer pseudoplatanus Sycamore Carex ovalis Oval Sedge Achillea millefolium Yarrow Carex remota Remote Sedge Aethusa cynapium Fool's Parsley Cerastium glomeratum S. Mouse-ear Chickweed Agrimonia eupatoria Agrimony Cerastium vulgare Mouse-ear Chickweed Agropyron pungens Sea couch-grass Chenopodium album Fat Hen Agropyron repens Couch-grass Cirsium arvense Creeping Thistle Agrostis canina Brown bent-grass Cirsium vulgare Spear Thistle Agrostis tenuis Common Bent-grass Conium maculatum Hemlock Aira praecox Early hair-grass Conopodium majus Pignut Allium vineale Crow Garlic Convolvulus arvensis Bindweed Alnus glutinosa Alder Crataegus monogyna Hawthorn Alopecurus pratensis Meadow Foxtail Crepis taraxifolia Beaked Hawk's beard Anagallis arvensis Scarlet Pimpernel Dactylis glomerata Cock's Foot Anemone nemorosa Wood Anemone Daucus carota Carrot Anisantha sterilis Barren Brome Deschampsia flexuosa Wavy hair-grass Anthoxanthum odoratum Sweet Vernal Grass Endymion non-scriptus Bluebell Armoracia rusticana Horse Radish Epilobium hirsutum Great Willowherb Arrhenatherum elatius Oat grass Equisetum arvense Common Horsetail Artemisia vulgaris Mugwort Euphorbia amygdaloides Wood Spurge Aster tripolium Sea Aster Euphorbia helioscopia Sun Spurge Atriplex hastata Hastate Orche Fagus sylvaticus Beech Atriplex littoralis Shore Orache Festuca ovina Sheep's Fescue Ballota nigra Black Horehound Festuca tenuifolia Fine-leaved Fescue Bellis perennis Daisy Fumaria officinalis Fumitory Beta maritima Sea Beet Galeopsis tetrahit Hempnettle Betula pubescens Birch Galium aparene Cleavers Brachypodium sylvaticum Slender false-brome Geranium dissectum Cut-leaved Cranes-bill Calystega sepium Large Bindweed Geranium molle Dove's foot Cranes-bill

Southampton WIldlife Lmk 23 Glaux maritima Sea Milkwort Petasites fragans Winter Heliotrope Hedera helix Ivy Phalaris arundinacea Reed-grass Heracleum sphondylium Hogwecd Phragmites communis Common Reed Hieracium perpropinqullm Hawkweed Plantago lanceolata Ribwort Plantain Ho1cus lanatus Yorkshire Fog Plantago major Greater Plantain Hordeum murinum Wall Barlev Plantago maritima Sea Plantain Hypericum pcrforatlll11 St. John's Wort Poa angustifolia Fine-leaved Poa Hypochoeris radicata Cat's Ear Poa annua AnnualPoa Hex aquifolium Holly Poa compressa Flattened Poa Iris pseudacorus Iris Poa nemoralis Wood Poa Juncus effusus Soft Rush Poa trivialis Rough-stalked MeadowGrass Juncus gerardii Mud Rush Polygonum aviculare Knotgrass Juncus maritimus Sea Rush Polygonum persicaria Persicaria Lactuca serriola Prickly Lettuce Potentilla sterilis Barren Strawberry Lamium purpureum Red Dead Nettle Prunus avium Wild Cherry Leontodon autumnalis Autumnal Hawkbit Prunus (domestica) sp. Plum Limonium vulgare Sea Lavender Prunus spinosa Blackthom Lolium perenne Rye grass Pteridium aquilinum Bracken Lonicera periclymenum Honeysuckle Quercus robur Pedunculate Oak Luzula campestris Field Woodrush Ranunculus acris Meadow Buttercup Luzula pilosa Hairy Woodrush Raphanus raphanistrum Wild Radish Luzula forsteri Forster's Woodrush Rosa arvensis Field Rose Lycopus europaeus Gipsy-wort Rosa canina Dog Rose Lysimachia vulgaris Yellow loosestrife Rubus fruticosus Bramble Malus (domesticus) sp. Apple Rubus idaeus Raspberry Malva sylvestris Common Mallow Rumex crispus Curled Dock Medicago arabica Spotted Medick Rumex obtusifolius Broad-leaved Dock Melica uniflora Wood Melick Sagina procumbens Pearlwort Melampyrum pratense Cow-wheat Salix cinerea Grey Willow Misopates orontium Lesser Snapdragon Salix fragilis Crack Willow Molinca caerulea Purple Moor-grass Sambucus nigra Elder Oenanthe crocata Hemlock Water-dropwort Sarothamnus scoparius Broom

Southampton Wildlife Link 24 Scirpus maritimus Sea Club-rush Teucrium scorodonia Wood Sage Senecio jacobaea Ragwort Trifolium dubium Lesser Trefoil Senecio vulgaris Groundsel Trifolium pratense Red Clover Sinapus arvensis Charlock Trifolium repens White Clover Sison amomum Bastard Stone Parsley Ulex europaeus Gorse Sisymbrium officinale Hcdge Mustard Urtica dioica Nettle Solanum dulcamara Bittersweet Veronica arvensis Wall Speedwell Solidago virgaurea Golden rod Veronica chamaedrys Germander Speedwell Sonchus arvensis Field Milk-thistle Veronica filiformis (alien) Creeping Speedwell Sonchus oleraceus Sow-thistle Veronica hederifolia Ivy-leaved Speedwell Sorbus aria sp. Whitebeam Veronica persica Large Field-speedwell Sorbus aucuparia Mountain Ash Vicia cracca Tufted Vetch Spartina townsendii X Cord Grass Vicia hirsuta Hairy Tare Stellaria holostea Greater Stitchwort Vicia sativa Common Vetch Stellaria media Chickweed Vicia tetrasperma Smooth Tare Symphoricarpus civularis Snowberry Viola riviniana Common Violet Tamus communis Black Bryony Vulpia bromoides Barren Fescue Taraxacum officinale Dandelion

Southampton Wildlife Link 25 Appendix 2: INSECTS Neuroptera: lacewings, etc. For some ofthe species an attempt has been made to produce some Chrysopa septempunctata (A) lacewing scale ofabundance. (A) abundant; (0) occasional: (R) rare but has been recorded Mecoptera: Panorpa communis (0) scorpion fly Please note that this is not an exhaustive list ofthe insects found at Chessel Bay but represents records available to date. Orthoptera: grasshoppers & crickets Chorthippus brunneus (0) Common Field Grasshopper Collembola: springtails Chorthippus parallelus (A) Meadow Grasshopper Entomobryoidea (0) Pholidoptera griseoaptera (0) Dark Bush-ericket Poduroidea (0) Tetrix sp. (R) Ground-hopper

Dermaptera: earwigs Diptera: true flies Forficula auricularia (A) Tipula maxima Crane fly Nephrotoma sp. Hemiptera: true bugs Bibio sp. St. Mark's Fly Amblytylus nasutus (A) Rhagio scolopacea Anthocoris nemorum (R) Bombylius major (0) Bee-fly Blepharidopterus angulatus (A) Bombylius minor (0) Bee-fly Cercopis vulnerata (0) Eristalis tenax (0) Drone Fly Jasid bugs/leafhoppers (A) Eristalis arbustorum Hover Fly Pentatoma shield bugs (A) Platychirus sp. Hover Fly Philaenus spumarius (0) Helophilus pendulus Saldula palustris (R) Volucella zonaria Volucella inanis Odonata: dragonflies Volucella bombylans Aeshna cyanea (0) southern aeshna Catabomba pyrastri Cordulegaster boltonii (0) gold-ringed dragonfly Rhingia campestris Libellula depressa (0) broad bodied libellula Trypetid spp. Picture-wing Fly Coenagrion puella (0) blue coenagrion damselfly Calliphora vomitoria Blow Fly Pyrrhosoma n}111phula (0) large red damsclfly Lucilia sp. Green Bottle Sarcophaga sp. Grey Flesh Fly

Southampton Wildlife Link 26 Hymenoptera: bees & wasps Gatekeeper (0) along railway line Bombus lucorum bumble bee Bombus lapidarius bumble bee Hesperidae Bombus terrestris bumble bee Large & Small Skippers in rough grass areas Apis mellifera honey bee Andrena sp. mining bee Lvciaedae Halictus sp. mining bee Small Coppers common in grass areas Vespa crabro hornet Purple Hairstreak (0) Vespula vulgaris common wasp Holly Blue (A) Chrysis ignita ruby tail wasp Common Blue (A) various species of ichneumons Ophion sp. Nymphalidae Andricus kollari gall wasps Small Tortoiseshell (A) Andricus fecundator Peacock (0) Neuroterus quercusbaccarum spangle gall wasp Comma (0) Biorrhiza pallida oak apple gall Painted Lady (0) in autumn Nematus ribesii sawfly Red Admiral (0) common on plum trees

Coleoptera: beetles Pieridae Lucanus cervus Stag Beetle Large White (A) Dorcus parallelopipedus Lesser Stag Small White (A) Crioceris aspargi Asparagus beetle Green-veined White (0) Agonum assimile Ground beetle Brimstone (A) Pterostichus madida Ground beetle Orange-tip (0) In spnng Carabus violaceous Violet ground beetle Sphingidae Carabus arvensus Lime Hawk Moth (R) Melalontha melalontha Cockchafer Poplar Hawk Moth (R)

Lepidoptera: butterflies and moths Arctiidae Satyridae Cinnabar Moth (0) Speckled Wood (A) throughout wooded area Satyrnidae Meadow Brown (A) in rough area near Hazel Rd BuffTip Moth (0)

Southampton \Vi Idlife Link 27 APPENDIX 3: VERTEBRATES

Reptiles Slow-worm Common Lizard Grass Snake

Mammals Hedgehog Common Shrew Pipistrelle Bat Fox Roe Deer Wood Mouse House Mouse Brown Rat

Southampton Wildlife Lmk 28 APPENDIX 4: MUDFLAT COMMUNITY

Algae Green alga Entcromorpha intestinalis an amphipod crustacean Gammarus duebeni Sea lettuce Ulva lactuca Bladdcrwrack Fucus vesiculosus FISH: Spiral wrack Fucus spiralis 3 - spined stickleback Gasterosteus aculeatus 15 - spined stickleback Spinachia vulgaris At leat 21 different species ofdiatoms including pipefish Syngnathus acus • Pleurosigma Flounder Platichthys flesus • the Sliding Diatom • Euglena

MICROFAUNA • rich variety of zooplankton including copepods and ciliates • in mid summer dense population of foraminiferans • nematodes

INVERTEBRATES: Nemertine worms Lineus sp. Ragworm Nereis diversicolor Sand gaper Mya arenaria Peppery furrow shell Scrobicularia plana Baltic tellin Macoma balthica Laver spire shell Hydrobia ulva Common shore crab Carcinus maenas Sea slater Ligia oceanica Sandhoppers Orchestia gammarella an isopod crustacean Corophium volutator an isopod crustacean Cyathura carinata

Southampton Wildlife Link 29 APPENDIX 5: BIRDS FOUND AROUND Redshank CHESSEL BAY Curlew Oystercatcher Lesser black back Woodland Greater black back Kestrel Herring gull SparrO\vhawk Robin Common gull Wren Ring plover Dunnock Turnstone House Sparrow Mute swan Blue tit Merganser, Red-Breasted Great Tit Mallard Blackbird Moorhen Song Thrush Coot Mistle Thrush Rock pipit Redwing Grey wagtail Goldfinch Pied wagtail Chaffineh Carrion crow Grey heron Shoreline Common sandpiper Cormorant Grey plover Little grebe Black head. gull Brent geese Dunlin

Southampton Wildhfe Link 30 RESULT OF BIRD COUNTS date 6.11.88 20.11.88 27.1.92 29.1.92 15.2.92 i pied wagtail 2 1 2 Table 1 Winter day counts 1988 & 1992 carnon crow 1 5 grey heron 1 date 6.11.88 20.11.88 27.1.92 29.1.92 15.2.92 common 1 sandpiper birds in bav Igrey plover 1 cormorant 12 2 3 4 6 little grebe 2 2 black head. gull 226 410 342 278 480 total count 565 867 531 496 642 brent geese 9 11 16 dunlin 131 320 136 145 76 tide state rising rising rising low low redshank 20 28 5 8 9 curlew 7 3 4 5 1 oystercatcher 30 4 13 14 11 lesser black back 2 greater black 3 1 back herring gull 4 5 9 4 12 common gull 2 6 4 ring plover 40 60 2 1 turnstone 40 4 9 18 16 mute swan 4 2 6 merganser, Lb. 1 mallard 31 15 moorhen 2 coot 2 rock pipit 3 1 I.grey wagtail 4 I

Southampton Wildlife Link 31 Table 2 Half Hourly Counts October 1992 Table 3 Half Hourly Counts November 1992 Count 1 Date: 26th October 1992 time: between Count 2 Date: 21 st November 1992 time: between 3:15 & 5: 15 pm 11 :45 & 1:45 pm

Bird Species 3: 15 3:45 4: 15 4:45 5: 15 max Bird Species 11 :45 12: 15 12:45 1: 15 1:45 max Cormorant 1 4 3 3 3 4 Cormorant 1 3 3 2 3 3 Mute Swan 2 1 1 2 Mute Swan 4 7 7 6 8 8 Mallard 7 9 2 2 2 9 Brent Goose 34 45 42 34 22 45 Oystercatcher 15 16 2 1 1 16 Mallard 4 2 16 6 7 16 Ringed Plover Little Grebe 3 3 3 3 3 3 Redshank 14 30 21 22 30 Coot 1 1 1 1 Curlew 1 2 1 1 2 2 Oystercatcher 5 7 11 4 11 Black Headed Gull 110 215 255 285 295 295 Ringed Plover 2 2 Common Gull 2 2 Tumstone 6 6 1 6 Herring Gull 7 7 6 1 7 7 Dunlin 33 55 68 5 25 68 Great Black-Back Gull 1 1 Redshank 16 15 16 9 14 16 Grev Wagtail 1 1 1 1 Curlew 1 2 3 3 3 3 Kingfisher 1 1 1 Black Headed Gull 125 200 235 180 230 235 Common Gull 1 1 1 Low Tide at 5: 15 pm Total Herring Gull 6 2 5 1 6 Count: 370 Great Black-Back Gull 1 1 1

Low Tide at 1:15 pm Total Count: 425

Southampton WIldlife Link 32 \

ACKNO\VLEDGEMENTS

Members of the Wildlife Link were the principle individuals responsible for collecting the data used in this report. In particular the following Mary Smith and Pat Loxton for the flora of the woodland & marsh. Philip Budd, Julian Cremona and Chris Piatkiewicz for the invertebrates ofthe woodland. Bird Counts made by Philip Budd, Chris Bou[en, Julian Cremona and other committee members. Julian Cremona for invertebrates and algae of mudflats. We would like to thanks British Gas for helping to finance this report and the conservation at Chessel Bay.

Cover Photographs (by Julian Cremona)

Front Cover: An aerial view of Chesscl Bay. looking south-west across to Southampton City Centre

Back Cover: Top left - the mud surface, magnified 200x. showing diatoms Top right - the crustacean, CorophiuJII, in its burrow Bottom left - the Ringed Plover. whieh feeds on Corophiu/l1 & Hvdrobia Bottom right - a closeup of the head of the Common Shore Crab. Carein us JIIaenos