Comparisons of Arctic Cod, Arctic Staghorn Sculpin, and Shorthorn Sculpin diets throughout the northeastern Chukchi and western Beaufort Seas

Abstract

Diet information for Arctic Cod (Boreogadus saida), Arctic Staghorn Sculpin (Gymnocanthus tricuspis), and Shorthorn Sculpin (Myoxocephalus scorpius) in the northeastern Chukchi and western Beaufort seas is mostly descriptive. In this study, I examined diet variability due to region, depth, and body size by quantitatively comparing these fishes' diet compositions. To accomplish this, I analyzed the stomach contents of 1,620 fishes collected over three summers in the northeastern Chukchi Sea (2010-2012) and one summer in the western Beaufort Sea (2011). In general, body size and region accounted for most differences in diets. As body size increased, each species consumed a more varied diet composed of larger prey. Additionally, each species consumed more benthic prey taxa in the northeastern Chukchi Sea than in the western Beaufort Sea. These findings indicate that a combination of both body size and region-specific oceanographic processes are likely driving the observed variability in these species' diets. Documenting this variability provides a better insight into the present relationships between these fishes and their prey over a large area and offers a benchmark for future diet analyses in the western Arctic.