Genetic stock composition analysis of chum salmon from the prohibited species catch of the 2016 Bering Sea walleye pollock trawl fishery and Gulf of Alaska groundfish fisheries.

• Main Authors: Whittle, J. Jackie, Kondzela, Christine M., Nguyen, H. T. Hanhvan T., Hauch, K., Cuadra, D. Dione, Guyon, Jeffrey Robert
• Format: Text
• Language: unknown
• Published: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center 2018
• Subjects: Yukon; Bering Sea; Gulf of Alaska; Pacific; Keta; Alaska
• Online Access: https://dx.doi.org/10.7289/v5/tm-afsc-366; https://repository.library.noaa.gov/view/noaa/17119

A genetic analysis of the prohibited species catch (PSC) of chum salmon (Oncorhynchus keta) collected during 2016 from the federally managed walleye pollock (Gadus chalcogrammus) trawl fishery in the Bering Sea and from the federal groundfish fisheries in the Gulf of Alaska (GOA) was undertaken to determine the overall stock composition of the sample sets. Samples were genotyped for 11 microsatellite markers from which stock contributions were estimated using the current chum salmon microsatellite baseline. In 2016, one genetic sample was collected for every 30.6 chum salmon caught in the Bering Sea midwater trawl fishery. The evaluation of sampling in the Bering Sea based on time, location, and vessel indicated that the genetic samples were representative of the total chum salmon PSC in the Bering Sea. The majority of the 114 chum salmon samples from the A-season were from Northeast Asia (37%) and Eastern GOA/Pacific Northwest (PNW) (37%) stocks. Based on the analysis of 2,701 chum salmon collected throughout the B-season, the largest stock groups in the catch were Eastern GOA/PNW (35%) and Northeast Asia (31%), followed by Western Alaska (19%), Southeast Asia (9%), Upper/Middle Yukon (5%), and Southwest Alaska (< 2%) stocks. The chum salmon caught in the Bering Sea in 2016 shared general patterns of stock distribution with those from past years, but differed by some finer-scale spatiotemporal strata. Of the 473 chum salmon samples from the GOA groundfish fisheries, the highest proportion was from Eastern GOA/PNW (93%) stocks, similar to previous years.