Regional patterns of continental shelf polychaete diversity: examples for the North Sea, English Channel, Irish Sea and Outer Bristol Channel areas

Polychaetes are a well-represented group in most marine and estuarine environments, both in terms of number of individuals and species; they typically constitute a significant percentage of the total macrofaunal diversity. The aim of our analyses was to characterise the biodiversity and regional distribution patterns of polychaete assemblages from the continental shelf (0-200 m) of the North Sea, English Channel and Irish Sea. Variations in depth and local distribution of sediment types, amongst other environmental factors, are the main factors affecting the pattern of distribution of benthic polychaetes. Here we applied and compared different approaches to draw the diversity pattern of this marine invertebrate group on a regional biogeographical scale, and to identify the main factors structuring these patterns.