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Fraser River Sockeye Fisheries and Fisheries Management - Cohen ...

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Appendix I Methods of In-season Stock Assessmentby the Pacific Salmon Commission.Pacific Salmon Commission600 - 1155 Robson StreetVancouver, B.C.V6E 1B5(604) 684-8081(604) 666-8707 (fax)To: Mike LapointeFrom: Jim CaveDate: December 7, 2010Re: Methods of In-season Stock Assessment: Test fishing CPUE <strong>and</strong> catchability.As requested, I am summarizing the methods for In-season Stock Assessment. Theseinclude run-reconstruction <strong>and</strong> run-size estimation based on test fishery catch-per-uniteffort,(CPUE) data <strong>and</strong> estimates of catchability. Note that I am not including catchestimation, stock identification or hydroacoustics methods as these are the subject ofdiscussion in other documents.OverviewRun-size estimation for <strong>Fraser</strong> <strong>River</strong> sockeye (by stock group) <strong>and</strong> pink salmonhistorically was based primarily on catch, effort, escapement <strong>and</strong> racial composition.Traditionally, most of these data for Summer <strong>and</strong> Late-runs come from commercialfisheries. However, limited commercial fishing in recent years has reduced theavailability of this source of data. Test fishing catch <strong>and</strong> CPUE data are now used moreextensively in assessing sockeye <strong>and</strong> pink salmon abundances than in previous years.These data are analyzed using a cumulative-normal model, which is described inpreviously published reports (PSC 1995, 1998). Since 2001, a Bayesian “Box-Car” orI-1

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