Quantifying biodiversity is an important function in these days of climate change and species extinction. Surprisingly, we know relatively little of the diversity and distribution of the animals inhabiting the seabed off our coasts.

The macrofauna of the seabed mainly comprise the polychaetes (bristleworms), molluscs (shells and slugs), crustaceans (including shrimps, prawns and crabs) and echinoderms (starfish, sea urchins, sea cucumbers). These animals together form an important component of food webs and their activities within the sediments contribute to the health of the marine environment — for example, through sediment turnover and the processing of organic matter. The majority of species are essentially sedentary, and therefore changes in their community structure and diversity can be examined in relation to natural and human-related disturbance.

We have been actively exploring the seabed animals of the Irish Sea and Bristol Channel for over 20 years. These investigations are published in the BIOMÔR Reports series and additionally provide much of the material used for taxonomic study. In addition, we have carried out comparable surveys in other climates, particularly sub-tropical Hong Kong and tropical Seychelles. The information acquired from these will help us to better understand differences in marine biodiversity worldwide.