Pollock Conservation Cooperative Research Center
2009 Awarded Research Projects
Project Title: Feeding patterns, prey selection, and potential dietary overlap of age-0 pelagic juveniles of walleye pollock (Theragra chalcogramma) and Pacific cod (Gadus macrocephalus) during a cold summer in the eastern Bering Sea
Principal Investigator: Nicola Hillgruber
Award: $56,394
Abstract
The goal of this study is to examine feeding patterns of pelagic late larval and early juvenile walleye pollock (Theragra chalcogramma) and Pacific cod (Gadus macrocephalus), collected in early summer of an exceptionally cold year (2008) on a large scale station grid ranging from Unimak Pass to the vicinity of St. Lawrence Island in the eastern Bering Sea. Previous studies have found that growth, and thus feeding success, during the first summer of marine fishes are important conditions for overwinter survival and, subsequently, recruitment success. This proposed study will benefit greatly from available data on summer zooplankton abundance, composition, and biomass, and on fish energy content, which were collected as part of the Bering Ecosystem Studies (BEST) and the Bering Sea Integrated Research Project (BSIERP), respectively; however, to date no funding is available to examine the feeding patterns of these co-occurring, economically and ecologically important groundfish species. The proposed study will form the basis for a M.S. thesis at the School of Fisheries and Ocean Sciences. As such, the proposed study will directly follow the PCCRC guideline by supporting research and education on pollock and other groundfish species; specifically, we will address priority 2 Alaska pollock Stock Dynamics by examining the relationship of secondary production on pollock (and cod) recruitment. Results from this study will provide first insight into resource allocation and the potential for dietary overlap and may allow the assessment of the probability of food competition between early pelagic life stages of walleye pollock and Pacific cod in early summer during an exceptionally cold year in the eastern Bering Sea.
