2016 Genetic stock Composition Analysis of the Chinook Salmon (Oncorhynchus tshawytscha) Bycatch from the Bering Sea Walleye Pollock (Gadus chalcogrammus) Trawl Fishery

Amendment 91 to the North Pacific Fishery Management Council Fishery Management Plan for groundfish of the BSAI Management Area was enacted in 2010 and included retention of the all salmon caught in the pollock fishery. In 2011, a systematic random sampling design recommended by Pella and Geiger was implemented by the Alaska 2 Fisheries Science Center’s Fisheries Management and Analysis North Pacific Groundfish and Halibut Observer Program (Observer Program) to collect genetic samples from one out of every 10 Chinook salmon encountered as bycatch in the BS pollock fishery.

In 2016, genetic samples were collected by the Observer Program from the Chinook salmon bycatch of the BS pollock fishery by using the systematic sampling protocols recommended previously. The number of available samples and the unbiased sampling methodology facilitated the extrapolation of the sample stock composition to the overall Chinook bycatch from the BS pollock trawl fishery in 2016. Stock composition analyses were performed using the single nucleotide polymorphism (SNP) baseline provided by the ADF&G, the same baseline that was used previously to estimate stock composition of samples from the 2005-2015 Chinook salmon bycatch.