DISTRIBUTION, POPULATION-STRUCTURE AND DIET OF SILVERY POUT (GADICULUS-ARGENTEUS-THORI SCHMIDT,J.), POOR COD (TRISOPTERUS-MINUTUS-MINUTUS (L)), 4-BEARDED ROCKLING (RHINONEMUS-CIMBRIUS (L)), AND VAHLS EELPOUT (LYCODES-VAHLII-GRACILIS REINHARDT) IN THE NORWEGIAN DEEP

Populations of some small, demersal roundfish in the Norwegian Deep of the northeastern North Sea were analysed. Data were collected on 3-4 bottom trawl surveys each year in four years. Both silvery pout, four- bearded rockling and Vahl's eelpout were moderately abundant in parts of the Norwegian Deep. The area is deeper than the normal range of dis tribution of poor-cod and this species only occurred along the edges o f the deep-water area. The abundance of silvery pout increased towards the northwest, whereas four-bearded rockling and Vahl's eelpout were more abundant in the Skagerrak. There were some indications of seasona l or ontogenetic migrations. Only 2-3 age groups were present at a tim e in the silvery pout and four-bearded rockling populations, whereas s even age groups of Vahl's eelpout were recorded. Pelagic or benthopela gic crustaceans formed important parts of the diets of all the four sp ecies considered. In addition, poor-cod and four-bearded rockling prey ed on polychaetes, whereas Vahl's eelpout ate ophiurids. Interspecific differences in diet composition were found and the similarity of nich e characteristics were relatively low.