The Diet of Grey Seals Around Orkney and Other Island and Mainland Sites in North-Eastern Scotland

Abstract

Almost 1000 faeces were collected in February, June, August and November 1985 in order to quantify the diet of grey seals around Orkney; 82% of these contained fish otoliths. Diet composition, by weight, was assessed by identifying and measuring otoliths from the faecal material and correcting for reduction in otolith size as a result of digestion using experimentally derived species-specific digestion coefficients. Sandeels accounted for almost half the fish consumed, by weight. The rest of the diet was composed mostly of gadids (particularly cod), flatfish (particularly plaice), and sculpins