Summer diet of grey seals (Halichoerus grypus) in Faroese waters

Summary

The ecological role of grey seals (Halichoerus grypus) as predators in Faroese waters was evaluated, based on reconstruction of the diet composition from stomach contents obtained from animals taken for scientific purposes in three main sampling areas during the summer in 1993-1995. Gadoids, sandeels (Ammodytes sp.) and catfish (Anarhichas lupus) dominated the seal diet. Some regional variations were found in the grey seat diet, where gadoids and sandeels were most important in the Svinoy area, catfish and gadoids were most important in the Sandoy area, and sandeels and gadoids were most important in the Northwest area. Regional variations in diet may reflect variations in the abundance and availability of potential prey. Grey seals of different ages were found to have somewhat different feeding habits. Juveniles fed most frequently on sandeels, pre-adults fed on sandeels and saithe (Pollachius virens) and adults fed on cod (Gadus morhua) and catfish. Adults also fed on larger prey than the younger seals. The grey seals in Faroese waters were only observed to feed on fish, generally smaller than 30 cm in length, but the size range differed among prey species.