Publication Abstract

The distribution, structure and diversity of fish assemblages in the Irish Sea

S.I. Rogers, M. Armstrong, J.R. Ellis, and M. Service

The fish assemblages of the Irish Sea are described from annual otter and beam trawl surveys. Data from otter trawls indicated that four fish assemblages were present in the Irish Sea. The inshore waters of the western Irish Sea were characterised by a high abundance of herring and sprat, whereas Norway pout, witch and long-rough dab were characteristic of the Nephrops fishing grounds west of the Isle of Man. Several flatfish species, including plaice and dab, dominated the inshore grounds of the eastern Irish Sea, whereas various elasmobranchs (e.g. spotted and cuckoo rays), and red gurnard were more abundant on the coarser offshore grounds in the central Irish Sea. Data from beam trawl surveys indicated that three demersal fish assemblages were present. No major dichotomy between the inshore waters of the eastern and western Irish Seas was observed, and sole, plaice and dab dominated beam trawl catches in both these areas. Once again, the grounds west of the Isle of Man were distinguished by a greater abundance of witch, a species known to favour muddy substrates, and the coarser offshore grounds of the eastern Irish Sea had a diverse ichthyofauna. The diversity of these fish assemblages is discussed in relation to natural and anthropogenic factors, and in relation to the historical faunal lists for the area.

Reference:

S.I. Rogers, M. Armstrong, J.R. Ellis, and M. Service. 2003.The distribution, structure and diversity of fish assemblages in the Irish Sea. Marine biodiversity in Ireland and adjacent waters (J.D.Nunn, ed.). Ulster Museum, Belfast, 93-114.