en :z: c::> I­ <I; (!) Ma";n~ f(luna of Colinty~Wexford,lreIQnd: t",e FCI,un':' I­ "" ',' " , " " en ....... >­ .. ot:Rock.yShor:es.~nd Sandy Beac.hfls :z: en ....... c:: ....... \, c::> :z: en ....... c:: ....... en 3!: ....... :z: Irish Fisheries Investigations (New Series) No.2 - 1998 MARINE FAUNA OF COUNTY WEXFORD, IRELAND: THE FAUNA OF ROCKY SHORES AND SANDY BEACHES by BRENDA HEALY AND DAVID MCGRATH . I Dublin The Marine Institute, 80 Harcourt Street, Dublin 2 Copyediting and technical typesetting by Mayo Editorial Services ISBN 0-7076-2300-6 CONTENTS ABSTRACT 1 INTRODUCTION 1 THE WEXFORD COASTLINE 3 ENVIRONMENTAL FACTORS 5 METHODS 6 Rock surfaces 7 Cryptofauna of rocky shores 7 Boulder shores 7 Sandy beaches 8 RESULTS 8 Description of rocky shores at Carnsore 8 Faunal records for rock and boulder shores 9 The exposed shore at Carnsore Point 9 I Description 9 Rock surfaces 10 Cryptofauna 12 Pools. 14 Dynamics of the exposed shore community 15 IIi The sheltered shore at Carnsore point 16 I Description 16 Rock surfaces 16 The sublittoral fringe 16 I Cryptofauna 16 Pools 17 The rocky shore at Forlorn Point 17 I The rocky shore at Hook Head 18 The rocky shore at Cahore Point 18 Faunal studies on boulder shores in SE Wexford 19 Reproduction and population dynamics of dominant rocky shore species 19 Semibalanus balanoides 23 Chthamalus montagui and C stellatus 23 [dotea granulosa 26 [dotea pelagica 27 Palaemon elegans 27 Porcellana platycheles 27 Patella vulgata 27 Patella ulyssiponensis (syn. P. aspera) 29 Helcion pellucidum 30 Gibbula umbilicalis 30 Gibbula cineraria 32 Monodonta lineata 32 Littorina littorea 33 Littorina neglecta 35 Melarhaphe neritoides 35 Nucella lapillus 35 Mytilus edulis agg. 36 iii Lasaea rubra 37 Depositing shores 37 Faunal records 37 Sandy beaches 38 Kilmore Quay beach 41 Camsore beach 41 Came beach 42 Rosslare Harbour beach 43 Rosslare Point beach 43 Coombe beach 44 BannowBay 44 Other beaches 44 Mud flats and salt marshes 44 Strandings 44 Observations on some amphipods of sandy beaches 45 Methods 45 Results 45 Bathyporeia spp. at Came and Camsore 45 Haustorius arenarius 47 Discussion 47 DISCUSSION 48 ACKNOWLEDGEMENTS 51 REFERENCES 51 I I j 1 <! j j I ! I, iv -------"~-----------, MARINE FAUNA OF COUNTY WEXFORD, IRELAND: THE FAUNA OF ROCKY SHORES AND SANDY BEACHES BRENDA HEALyl AND DAVID MCGRATH2 iDepartment of Zoology, University College, Dublin 2Department of Life Sciences, Galway-Mayo Institute a/Technology and Department a/Zoology and Animal Ecology, University College, Cork ABSTRACT Infonnation accumulated during 20 years of investigations on the coast of County Wexford is summarised. Topics include shore descriptions, faunal records, transectal surveys on rocky shores and sandy beaches, cryptofaunal studies on rocky shores, and ecology, reproduction and population dynamics of many of the dominant species. Studies were mainly carried out on exposed and sheltered rocky shores in the region of Camsore Point, Forlorn Point and Hook Head, and sandy beaches at Kilmore Quay, Camsore, Came, Rosslare Harbour and Rosslare Point, but some collections were made in a wide range of habitats throughout the county. A total of 484 taxa were recorded. Carnsore is the type locality for four species of oligochaete and two more are yet to be described. The fauna lacks some of the elements of west Irish coasts but is richer than on the mid~eastern coast owing to the presence of southern species. Differences in species abundance and population structure on south and east coasts are described, and possible reasons for the differences are discussed. Key Words: marine, intertidal fauna, distribution, life histories INTRODUCTION In 1976, the Electricity Supply Board commis­ thus been accumulated. Some of the faunal sioned a baseline survey of the littoral fauna at records have already been published (McGrath Carnsore Point, at that time the proposed site for a and O'Sullivan, 1977; Healy, 1979a; O'Connor, nuclear power station. Prior to this survey, there 1980; 6'Ceidigh and McGrath, 1981; Healy and were no published accounts of shore communities' McGrath, 1982; McGrath, 1984;'Healy and Mc­ in Co. Wexford and few records of marine fauna. Grath, 1988; O'Connor, 1988; Healy, 1996a), the A list of Crustacea in the National Museum (O'Ri­ ecology, reproduction and popUlation dynamics of ordan, 1969), for example, lists only three species a few of the species have been described (Healy from Wexford localities, one of which was from and O'NeiU, 1984; McGrath and 6'Foighil, 1986; the sublittoral. Southward and Crisp (1954) gave McGrath, 1992; Myers and McGrath, 1993; Hea­ quantitative estimates of some rocky shore species ly, 1996b; McGrath, 1997), and some information (mainly barnacles and top sheUs) at 11 Wexford and species records have been published as part of localities and Bracken and Kennedy (1967) re­ studies with a wider scope (O'Connor and Mc­ corded ten species of fish taken in beach seines on Grath, 1978; Healy, 1979b; Ottway et al., 1979; a number of beaches. A few other species records Wilkins and O'Regan, 1980; McGrath, 1982, are contained in publications of a more general na­ 1985; McGrath et al., 1988; CosteUo et al., 1989; ture. Algae were recorded by Tighe (1803), Healy, 1990; O'FarreU and Fives, 1990; McGrath Parkes and ScanneU (1969), and Norton (1970). and King 1991, 1992). Other contributions to our knowledge of the Wexford coastline during this Between March 1976 and December 1978, the period include records of 17 species of Halacarina area was visited monthly and we had an opportu­ (Somerfield, 1988) from Carnsore Point and Hook nity not only to carry out detailed studies at the Head, and three species ofTalitridae (Hudson and Point but also to visit other shores in the area. The Reynolds, 1985). Algal records are given by information coUected in this period has been sup­ Guiry et at. (1979), and Whelan and CuUinane plemented by records obtained during occasional (1979). As yet, there has been no attempt to de­ visits in subsequent years and by data from more scribe the shores or their communities, or to char­ detailed studies of some of the more abundant spe­ acterise the region in terms of environmental cies. A considerable amount of information has influences. Irish Fisheries Investigations New Series, No.2 (1998) r ------ Irish Fisheries Investigations (New Series) No.2 (1998) The Wexford coastline comprises a wide range of south-west, west, and north-east where the rich landforms and habitats. The area is chiefly known faunas of regions such as Lough Hyne, Clare Is­ for its birds, the inlets, lagoons and sloblands at­ land and Strangford Lough are relatively well tracting large numbers of wintering waterfowl, in­ documented. The information provided in this pa­ cluding species of national and international per thus helps to contribute to our knowledge of importance (Merne. 1974; Sheppard, 1993), but the Irish marine fauna. the dune systems are also valued and have attract­ ed the attention of geomorphologists as well as This paper brings together information on intertid­ botanists. The sand and gravel barriers of the al fauna accumulated over 20 years of investiga­ south and east coasts are the most impressive in tions on the coast of Co. Wexford. It describes the Ireland (Ruz, 1989), while the two large lagoons, main features of the Wexford coastline between Lady's Island Lake and Tacumshin Lake, con­ Pollshone and Hook Head and provides details of tained behind the southern barrier, are among the rocky shore communities, chiefly in the region of best examples of percolating lagoons in western Carnsore, including summary accounts of repro­ Europe (Orford and Carter, 1982). In contrast, the duction and population dynamics of most of the intertidal zone presents no special features or hab­ dominant species. A brief account of the main itats likely to contain a rich invertebrate fauna characteristics and faunO! composition of some such as rapids, sea loughs and protected shores on sandy beaches is also given, and some records for the open coast, and the region has not, therefore, mud flats and salt marshes are listed. Non-tidal attracted collectors. Consequently, the intertidal brackish waters (lagoons and artificial impound­ fauna of this section of the Irish coastline is poorly ments) are not included and accounts of these may known by comparison with parts of the be found in Healy et al. (1982), Norton and Healy , , II'I' Ii Ii! " (' , ," Greenore Point Forlorn Point Carnsore' Point ~ Hook Head f7 Saltee Is. 10km Figure 1. Co. Wexford. 2 - ----- -~~~~~~~~- B. Healy and D. McGrath: Marine Fauna of County Wexford, Ireland (1984), Galvin (1992), Hurley (1997), and Healy our own field and laboratory notebooks. Together (1997). Some of the observations have already they provide a description of the shores and their been published (see above) but most of the data inhabitants, which allows comparison with simi­ are derived from unpublished reports, especially lar habitats elsewhere and highlights the predom­ Healy and McGrath (1986), student theses, and inant environmental influences in the area. THE WEXFORD COASTLINE The coastline of Co. Wexford is dominated by stone occur along the shore near Rosslare Har­ barrier systems, interrupted by rocky headlands bour. From Rosslare a long sand spit, bordered to representing the resistant outcrops of SW-NE the east by an exposed sandy beach, extends trending Palaeozoic rocks, and two major embay­ northwards to Rosslare Point. This stretch has ments, Wexford Harbour and Bannow Bay. There been starved of sand following construction of the are few lengthy outcrops of rock and the only Rosslare Harbour }lier and continues to erode, in large islands are the two Saltee Islands lying 7 km spite of a series of wooden groynes and several south of Kilmore Quay (Figs. I, 2).