BIOM6R1: Benthic Biodiversity in the Southern Irish Sea.

As Marine Recorder I am always interested to hear that major marine benthic surveys are carried out by commercial companies or other organisations as these are a potentially valuable source ofbiogeographical data for the Society's Census schemes. However I am also frequently frustrated by the fact that the results are never published or that release of data is 'difficult' for commercial reasons. It is, therefore, a delight to see the results of a comprehensive survey published in full.

The publication of this first Biomor report marks the completion of a significant phase of research in the marine areas around Wales. Two surveys of benthic invertebrates in the southern Irish Sea were carried out in 1989 and 1991 during which some 1030 species were recorded. The area is important as it has a fauna reflecting its position as a boundary between 2 biogeographical provinces (the Boreal province of the north and the Lusitanian to the south) and yet large parts of the Irish Sea were and still are poorly known. The sampling programme consisted of dredged and grabbed stations to obtain biological material for taxonomic investigation, determination of faunal composition and diversity of assemblages, and eventual integration into the Museum's reference collections An important feature of this survey was that the samples were sieved over a 0-5 mm mesh sieve rather than the conventionally used 1 mm or 2 mm mesh. In addition, sediments were collected for analysis and seabed photography enabled still visual images to be obtained.

The integration of all this primary data has enabled the production of a substantial, comprehensive and highly informative report. Chapters on Historical Perspective, Sampling Methods and Treatments, and The Study Area precede the body of the report which describes the Benthic Macrofauna. Annelids dominate the fauna which is 80 infaunal and 20 epifaunal. The second and third largest groups were Crustacea and Mollusca. Each of these major groups is discussed in a separate section and new problems with taxonomy are addressed. This has resulted in the recognition of synonymies as well as descriptions of new species. Altogether, seven sections within the Macrofaunal chapter have been contributed by experts.

One of the great strengths of this report is the inclusion of a chapter dealing with Classification and Ordination. In this chapter the statistical methods used to define communities and assemblages are outlined, discussed and compared. The chapter is extensively illustrated with graphs and tables to depict the techniques and individual tests used and show the results. For completeness, all the raw data are included in the report as a set of Appendices enabling the reader to analyse the results for himself.

Final chapters describe the macrofaunal assemblages recognised by integrated analysis of the data and also identify species diversity using diversity indices. An Overview summarises the findings within 3 concise pages. An extensive bibliography and over 100 pages of appendices appear at the end of the report.

Members of this Society will be interested in the molluscan data which is discussed in a section contributed by lan Killeen. Over 150 species were found alive (77 bivalve and 61 gastropod species). Amongst these data arc many new, and updated from shell only, Sea Area records, particularly for S21 and S22. Many of these are for the smaller species such as Dikoleps nitens and Caecum glabrum, elements that are frequently missed by sieving over too coarse a sieve. So-called northern species such as Emarginuta crassa or Pulsellum lofotense were found living in deep water whereas previously recorded southern species such as Galeodea rugosa and Callista chione were not found. It is especially pleasing to see that the Caudofoveates and Solenogastres were collected and identified. Eight species were found, considerably increasing our knowledge of their distribution and ecology in British waters. Four of the mollusc species are illustrated including a very useful drawing of a juvenile Lutraria lutraria.

The report is published as a high quality A4 paperback and contains numerous figures and tables. The faunal distribution and facies maps are clear with the clever use of a limited range of grey and blue shades. Perhaps the use of more colours would have rendered the distributions more distinctive although this would have increased the production costs significantly. As it is, the sponsorship of the Marathon Oil Company has enabled a thorough record and elegant presentation of the research cruises and their results.

To call this publication a 'report' is to undersell its potential use and application. It sets a new benchmark for its genre. The comprehensive coverage of all aspects of the 2 surveys - it stops short of outlining the menus that were available to the crew and scientists aboard! - means that it is a useful text for students and workers in marine sciences and for benthic ecologists and serves as a model for others contemplating similar surveys.