Feeding of larval walleye pollock (Theragra chalcogramma) in the oceanic domain of the Bering Sea

Abstract

Feeding of larval walleye pollock was examined with respect to abundance and distribution of prey at six depths in the oceanic domain of the Bering Sea in April 1992. Walleye pollock larvae and copepod nauplii distribution peaked at 30 m depth. Among copepod nauplii, walleye pollock larvae selected for Metridia sp. and Microcalanus sp., but against Oithona similis, even though the latter were the most abundant prey taxon. In addition, the larvae selected for larger nauplii and tended to consume stages I and II Oithona similis and stages lll-V calanoid nauplii. Larvae at 30 m depth had the highest incidence of feeding and number of prey items ingested. Although the 30 m depth stratum provided best physical and foraging conditions, the overall low percentage of feeding larvae and low numbers of prey consumed, suggest that foraging conditions for larval walleye pollock at the time of sampling were below saturation feeding levels.