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 ove rlaps within layers were low (D<0.25), white the between layer food overlap was moderate (D=0.25-0.74) to high (D>0.74) using Schoener's index. Select ion of prey was density dependent. However, prey size also played an import ant role. The diet of whiting shifted from amphipods and mysids to fish wit h increasing predator length, and the length of prey consumed increased sig nificantly with length of whiting. The fact that the stomach contents diffe red between the feeding groups demonstrates the need for a sampling design that includes both pelagic and demersal habitats when trying to quantify th e diet of whiting. (C) 1999 The Fisheries Society of the British Isles.