Harp seal (Phoca Groenlandica) invasions in north Norwegian coastal waters: A preliminary report on age composition and feeding habits
Original version
This report is not to be cited without prior reference to the authorsAbstract
Since 1978 large numbers of harp seals (Phoca groenlandica) have
invaded areas of North Norway in winter and spring. In 1987 and
1988 dramatic increases occurred both in magnitude and geographic
extent of these seal invasions, and it is suggested that the
collapse of the Barents Sea capelin stock in 1985/1986 may have
been a contributory factor to this. Sampling of stomach contents
for food analyses and of teeth for age determinations was carried
out from harp seals taken as bycatch in Norwegian gill-net
fisheries in 1986 and 1988. It appears that the seal herds
comprised both immature and mature animals. The stomach analyses
suggested that feeding was opportunistic, with a variety of fish
(in particular the gadoid species cod, saithe, haddock and Norway pout, and the pelagic shoaling species herring and capelin) being
taken as prey. Prawns and squid were also consumed, but in
considerably lower quantities than fish.