Diet comparison between pelagic and demersal whiting in the North Sea

demersal whiting preyed upon (demersal) Norway pout and herring. Values of diet breadth were low for both feeding groups using Levin's index. Diet overlaps within layers were low (D0.74) using Schoener's index. Selection of prey was density dependent. However, prey size also played an important role.

The diet of whiting shifted from amphipods and mysids to fish with increasing predator length, and the length of prey consumed increased significantly with length of whiting. The fact that the stomach contents differed between the feeding groups demonstrates the need for a sampling design that includes both pelagic and demersal habitats when trying to quantify the diet of whiting. (C) 1999 The Fisheries Society of the British Isles.