Genetic stock composition analysis of the Chinook salmon bycatch from the 2015 Bering Sea walleye pollock (Gadus chalcogrammus) trawl fishery

A genetic analysis of samples from the Chinook salmon (Oncorhynchus tshawytscha) bycatch of the 2015 Bering Sea-Aleutian Island (BSAI) trawl fishery for walleye pollock (Gadus chalcogrammus) was undertaken to determine the overall stock composition of the bycatch. Samples were genotyped for 43 single nucleotide polymorphism (SNP) DNA markers and results were estimated using the Alaska Department of Fish and Game (ADF&G) SNP baseline. In 2015, genetic samples from the Bering Sea were collected using a systematic random sampling protocol where one out of every 10 Chinook salmon encountered was sampled. Based on the analysis of 1,757 Chinook salmon bycatch samples collected throughout the 2015 BSAI walleye pollock trawl fishery, Coastal Western Alaska stocks dominated the sample set (40%) with smaller contributions from British Columbia (22%), West Coast U.S. (WA/OR/CA) (15%), and North Alaska Peninsula (11%) stocks. Analysis of temporal groupings within the pollock "A" and "B" seasons revealed changes in stock composition during the course of the year with lower contributions of Coastal Western Alaska, North Alaska Peninsula, and Upper Yukon stocks and higher contributions of West Coast U.S. (WA/OR/CA), British Columbia, NW Gulf of Alaska, and Coastal Southeast Alaska stocks during the "B" season. [doi:10.7289/V5/TM-AFSC-342 (http://dx.doi.org/10.7289/V5/TM-AFSC-342)] by C.M. Guthrie, III, Hv.T. Nguyen, A.E. Thomson and J.R. Guyon. "January 2017." System requirements: Adobe Acrobat Reader. Includes bibliographical references (pages 29-30). 2017 NMFS (National Marine Fisheries Service) AFSC (Alaska Fisheries Science Center) Submitted http://doi.org/10.7289/V5/TM-AFSC-342 Public Domain 1864