2017 Genetic Stock Composition Analysis of the Chinook Salmon Bycatch from the Bering Sea Trawl Fisheries

June 05, 2017

Pacific salmon (Oncorhynchus spp.) are prohibited species in the federally managed Bering Sea groundfish fisheries, which are subject to complex management rules (NPMFC 2017a) that are in part designed to reduce prohibited species catch, hereafter referred to as “bycatch”. It is important to understand the stock composition of Pacific salmon caught in these fisheries, which take place in areas that are known feeding habitat for multiple brood years of Chinook salmon (Oncorhynchus tshawytscha) from many different localities in North America and Asia (Myers et al. 2007, Davis et al. 2009). Chinook salmon are economically valuable and highly prized in commercial, subsistence, and sport fisheries. Determining the geographic origin of salmon caught in federally managed fisheries is essential to understanding the effects that fishing has on Chinook salmon stocks, especially those with conservation concerns (NPFMC 2017a). This report provides genetic stock identification results for the Chinook salmon bycatch samples collected from the U.S. Bering Sea walleye pollock (Gadus chalcogrammus) trawl fishery. National Marine Fisheries Service (NMFS) geographical statistical areas (NMFS area) associated with the Bering Sea groundfish fishery (NMFS areas 509-524) and Alaska Department of Fish and Game (ADF&G) statistical areas1 are shown in Figure 1 and are used later in the report to describe the spatial distribution of the Chinook salmon bycatch and genetic samples.