Abstract

ABSTRACT The area off the Scottish east coast and around Orkney and Shetland has previously been identified as the single most important area for seabirds at sea in summer in the North Sea. Both colony studies and longterm observations during extensive surveys off the British east coast have shown that sandeels (Ammodytidae) are critical prey for most piscivorous species in the area, but also that foraging is restricted largely to a zone c. 80 km wide along the coast.This paper summarises the results of ten extensive cruises and reports on species composition, foraging distribution and interannual variations within the northwest North Sea.ince the late 1970s and early 1980s, seabirds at sea have been studied in the North Sea in a much more systematic way than previously. Computers were essential to process the (literally) millions of bird records obtained during many thousands of kilometres steamedin the area, and enabled complex distribution patterns to be analysed with ease. An early analysis by the European Seabirds at Sea database group (a network of institutes and individuals from all countries around the North Sea which collected data in a standardised way andstored the information in a single joint database) revealed species-specific, broad-scale distribution patterns for the entire North Sea area (Skov et al. 1995; Stone et al. 1995). It was shown that by far the most important area for seabirds in summer was situated in the northwest, off the Scottish east coast and around Shetland and Orkney, areas where many of Britain's largest seabird