Habitat selection and competition amongst 0-group gadidae off Mid-Norway

Abstract

Juvenile gadids and other co-occurring fishes were collected during August in the years 1981 to 1983 at the Møre coast (Mid-Norway). The gears used were pelagic trawl, bottom trawl, Danish seine and beach seine. All species collected were indentified and counted. Saithe and pollack were never observed in the pelagic hauls. Cod were abundarit pelagically in 1981, but had already settled in 1982 and 1983. Haddock and whiting were caught both pelagically and at the bottom during all years. Saithe, pollack and partly cod therefore seem to settle before August, while the other species are settling during this month. Cod settled mainly in shallow sheltered areas and were absent at the most exposed locations and in deep water. Haddock generally settled at greater depths and in more exposed areas than cod, but were also observed in the fjords. Saithe were caught mainly at exposed littoral locations, and pollack were found in shallow water both in exposed and sheltered areas. Whiting were less abundant than the others, but were found pelagically mostly inshore all over the area studied. Single specimens of settled whiting were found in the sheltered littoral and sublittoral. Although the distribution to some degree overlapped, it seemed that differences in distribution and size reduced competition between the juvenile gadids. In the beach seine hauls about 30 other species occurred, and some of these may compete with cod for food.