Genetic stock composition analysis of the Chinook salmon bycatch in the Gulf of Alaska Walleye pollock (Gadus chalcogrammus) trawl fisheries, 2013

The genetic stock composition of Chinook salmon (Oncorhynchus tshawytscha) samples from the 2013 U.S. Gulf of Alaska (GOA) trawl fishery for walleye pollock (Gadus chalcogrammus) was prepared to estimate stock-specific harvests. Genetic samples were collected in 2013 from Chinook salmon taken as byc...

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Bibliographic Details
Main Authors: Guyon, Jeffrey Robert, Munro, A. R., Jasper, J.
Format: Text
Language:unknown
Published: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center 2015
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Online Access:https://dx.doi.org/10.7289/v50r9mb1
https://repository.library.noaa.gov/view/noaa/4851
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Summary:The genetic stock composition of Chinook salmon (Oncorhynchus tshawytscha) samples from the 2013 U.S. Gulf of Alaska (GOA) trawl fishery for walleye pollock (Gadus chalcogrammus) was prepared to estimate stock-specific harvests. Genetic samples were collected in 2013 from Chinook salmon taken as bycatch in this fishery predominantly from NMFS statistical areas 620, 630, and 640. Samples were genotyped for 43 single nucleotide polymorphism (SNP) DNA markers and the results were estimated using the available coastwide baseline of SNP markers for Chinook salmon. While sample sizes varied widely and did not achieve the 10% target used to sample bycatch in the Bering Sea, by using a stratified estimator weighted by stratum-specific bycatch, it was possible to estimate the stock composition of the by catch with acceptable accuracy and precision for NMFS statistical areas 620, 630, and 640, areas which comprised 84% of the bycatch in 2013. Based on the analysis of 693 Chinook salmon bycatch samples, the proportions of reporting groups were determined to be as follows: British Columbia ( 43%), U.S. West Coast (42%), coastal Southeast Alaska (11%), Northwest GOA (3%), and others (< 1%). No stock composition estimates are provided for statistical areas 610 or 649 due to the small size of the bycatch or the limited number of available genetic samples.