Recruitment of cod (Gadus morhua), whiting (Merlangius merlangus) and pollack (Pollachius pollachius) in the Risør area on the Norwegian Skagerrak coast 1945 to 1985. In: Flødevigen rapportserie no 1, 1990

Abstract

0-group gadoids and other fishes from the shallow water zone were sampled with a beach seine at 22 fixed localities in the Risør area at the Norwegian Skagerrak coast. A series of 41 years (1945 - 85) has been analysed. Cod, whiting and pollack showed great variation in 0-group abundance, but no consistent trend over the period studied. There was a slight positive correlation between 0-group abundance of cod and pollack. Whiting showed no correlation to the others. There was a good correlation between the 0- and 1-group cod of the same year-class in the beach seine in the area. The catches of 0- and 1- group cod showed also a good correlation to the whole Norwegian Skagerrak coast, and two very good year-classes never followed each other. The Risør area was divided into six subareas, and the abundance in these subareas was closely correlated for cod and pollack, but only weakly for whiting. Cod and whiting were most abundant in protected areas, while pollack was most abundant at exposed stations. All species generally had an increase in mean length at increased exposure. There was no correlation between size and abundance, although the five smallest year-classes of cod and pollack had a lower mean size than average. There was no correlation between the abundance of any of the gadoids and of the other species studied.