Northwest Fisheries Science Center

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Document Type: Report
Center: NWFSC
Document ID: 6924
Title: Genetic estimates of stock compositions of 1983 Chinook salmon harvests off the Washington Coast and the Columbia River
Author/Editor: Fred M. Utter, David J. Teel, George B. Milner, D. McIsaac
Year: 1986
City: Seattle
Institution: Report of the Coastal Zone and Estuarine Studies Division, Northwest and Alaska Fisheries Science Center, National Marine Fisheries Service and the Washington Department of Fisheries
Date: 1986

Allele frequency data for 17 polymorphic protein coding loci from 88 populations of chinook salmon between British Columbia, Canada and California, U.S.A. were used to obtain maximum likelihood estimates of contributing populations to fisheries off the coast of Washington, U.S.A.  Data were available for the commercial troll fishery of May 1982 and for commercial, Indian, and sport fisheries during spring and summer 1983.  The major contributing group to May troll fisheries of both years was that segment of fish returning to areas of the lower Columbia River in fall.  Estimated contributions of this group (collectively called "tules") to this fishery were 76.5% in 1982 and 54.9% in 1983.  The estimated proportion of fall run fish destined for areas of the upper Columbia River (collectively called "upriver brights") was low (less than 5%) in both years, although these runs are known to make substantial contributions to more northern fisheries of Canada and Alaska.  A considerable difference for each year occurred in the estimated proportion of California fish (2.8% in 1982 and 18.7% in 1983).

Differences occurred among the fisheries and areas sampled in 1983.  Larger estimates for Canadian and Puget Sound (Washington) fish occurred in fisheries of northern areas; the largest was 41% for the Indian fishery in the Strait of Juan de Fuca.  A greater proportion of California fish in any particular area was taken in sport fisheries.  The subset of tule populations returning to the Kalama and Cowlitz River drainages was harvested at a higher rate in sport than in commercial fisheries.  This study demonstrates the capabilities of the involved procedures for generating timely and reliable estimates of stock composition and serves as a starting point for more detailed understandings of the oceanic distribution of chinook salmon populations.