Distribution and trophic ecology of some gadoid fish of the Norwegian deep

As part of a comprehensive study of fish assemblages of the deep-water area of the northeastern North Sea and Skagerrak called the Norwegian Deep, information was gathered on the ecology and biology of selected gadoid fish species, i.e. saithe (Pollachius virens), cod (Gadus morhua), whiting (Merlangius merlangos), blue whiting (Micromesistius poutassou), pollack (Pollachius pollachius), ling (Molva molva), blue ling (Molva dipterygia), tusk (Brosme brosme) and hake (Merluccius merluccius). Data were collected on trawl surveys in winter, summer and autumn of the years 1984–1987. The distribution, abundance, size and age composition and diet of each species were described and intraspecific differences in diet and distribution were considered. The entire Norwegian Deep, but particularly the western and southern slopes, serves as feeding area for all the nine gadoids considered and most of the species utilize the area as late juveniles and adults, some also as young juveniles. Blue whiting and saithe are the two more abundant gadoids and both are dominant species in the area. All the species are benthopelagic and epibenthic predators on fish and crustaceans.