The long-term impacts of fisheries on epifaunal assemblage function and structure, in a Special Area of Conservation E.M.A. Strain a, ⁎, A.L. Allcock b , C.E. Goodwin c , C.A. Maggs a , B.E. Picton c , D. Roberts a a Queen's University Belfast, School of Biological Sciences, Medical Biology Building, 97 Lisburn Road, Belfast BT7 1NN, UK b Department of Zoology, Ryan Institute, National University of Ireland Galway, University Road, Galway, Ireland c Department of Natural Sciences, National Museums Northern Ireland, 153 Bangor Road, Cultra, Holywood, County Down BT18 0EU, UK abstract article info Article history: Received 1 June 2011 Received in revised form 2 September 2011 Accepted 8 October 2011 Available online 17 October 2011 Keywords: Long-term Fishing Impacts Epifaunal Community Marine Protected Areas Fisheries can have profound effects on epifaunal community function and structure. We analysed the results from five dive surveys (1975–1976, 1980, 1983, 2003 and 2007), taken in a Special Area of Conservation, Strang- ford Lough, Northern Ireland before and after a ten year period of increased trawling activity between 1985 and 1995. There were no detectable differences in the species richness or taxonomic distinctiveness before (1975–1983) and after (2003–2007) this period. However, there was a shift in the epifaunal assemblage between the surveys in 1975–1983 and 2003–2007. In general, the slow-moving, or sessile, erect, filter- feeders were replaced by highly mobile, swimming, scavengers and predators. There were declines in the frequency of the fished bivalve Aequipecten opercularis and the non-fished bivalves Modiolus modiolus and Chla- mys varia and some erect sessile invertebrates between the surveys in 1975–1983 and 2003–2007. In contrast, there were increases in the frequency of the fished and reseeded bivalves Pecten maximus and Ostrea edulis, the fished crabs Cancer pagurus and Necora puber and the non-fished sea stars Asterias rubens, Crossaster papposus and Henricia oculata between the surveys in 1975–1983 and 2003–2007. We suggest that these shifts could be directly and indirectly attributed to the long-term impacts of trawl fishing gear, although increases in the supply of discarded bait and influxes of sediment may also have contributed to changes in the frequency of some taxa. These results suggest that despite their limitations, historical surveys and repeat sampling over long periods can help to elucidate the inferred patterns in the epifaunal community. The use of commercial fishing gear was banned from two areas in Strangford Lough in 2011, making it a model ecosystem for assessing the long-term recovery of the epifaunal community from the impacts of mobile and pot fishing gear. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Marine ecosystems are subject to an increasing number of anthropo- genic stressors (Halpern et al., 2008). One of the most conspicuous stressors is the worldwide increase in the use of mobile fishing gear including beam and otter trawls, seine nets, drags, ticklers and dredges (Collie et al., 2000; Crowder et al., 2008; Watson et al., 2006). Mobile fishing gear can have major impacts on benthic assemblage function and structure (de Juan et al., 2007; Kaiser et al., 1998; Tillin et al., 2006). However, in many ecosystems assessing and predicting the effects of mobile fishing gear on the benthic community are difficult because the impacts can vary through time, between habitats, and with the intensity of fishing effort and type of fishing gear used (Bradshaw et al., 2001; Kaiser et al., 2006; Veale et al., 2000). Repeated monitoring of benthic communities is one approach used to examine the long-term effects of mobile fishing gear on ecosystems (e.g. Bradshaw et al., 2002; Callaway et al., 2007; Frid et al., 2000; Hill et al., 1999; Kenchington et al., 2007). This approach requires the use of historical data from periods before widespread use of the gear. Often these data have a number of limitations in assessing impacts, because of variable taxonomic expertise, sampling biases and/or changes in methodology (Bradshaw et al., 2002; Callaway et al., 2007; Frid et al., 2000). In many ecosystems it can also be difficult to distin- guish the long-term impacts of fishing from other stressors, such as eutrophication, climate change and pollution (Callaway et al., 2007; Hill et al., 1999; Reisen and Reise, 1982). Despite these limitations, repeated historical surveys have provided valuable insights into the long-term effects of mobile fishing gear in the Bay of Fundy, Canada (Kenchington et al., 2007), English Channel (Callaway et al., 2007; Hill et al., 1999), Irish Sea (Bradshaw et al., 2002; Frid et al., 2000), Foveaux Straits, New Zealand (Cranfield et al., 2003; Hill et al., 2010) and Wadden Sea, Germany (Reisen and Reise, 1982). In these studies, analyses of changes in community assemblage, biological traits and the abundance or frequency of indicator species are three key approaches which have made useful contributions to Journal of Sea Research 67 (2012) 58–68 ⁎ Corresponding author. Tel.: + 44 2890975787; fax: + 44 2890975877. E-mail address: strain.beth@gmail.com (E.M.A. Strain). 1385-1101/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.seares.2011.10.001 Contents lists available at SciVerse ScienceDirect Journal of Sea Research journal homepage: www.elsevier.com/locate/seares