Radio Telemetry Investigation to Test Closure Assumptions Underpinning Escapement Estimates for the Harrison Stock (Fraser River Fall-run Age 0.3 Stock Group)

Canadian Department of Fisheries and Oceans (CDFO) Fraser Stock Assessment have been delivering a high-precision Chinook salmon mark-recapture program on the Harrison River since 1983. The Harrison River mark-recapture project is the escapement indicator stock for the Fraser River Fall stock group. Program staff also conduct a SSP mark recapture on Chilko River and annual mark-recapture programs on the Lower Shuswap, Middle Shuswap and Nicola rivers; which generate highly precise (CV < 15%) escapement estimates by age, sex, and hatchery contribution. CDFO staff have considerable expertise in the delivery of telemetric assessments of fish behaviour to determine whether or not assumptions of distribution and closure have been met. Fraser Stock Assessment staff have successfully conducted similar telemetry studies on the Lower Shuswap, Middle Shuswap and Chilko rivers.
The Chilliwack River exploitation rate indicator stock is used to represent the distribution of the Harrison Chinook stock. The mortality distributions from the CTC exploitation rate analysis, shows that the stock occurs mainly in the West Coast Vancouver Island (WCVI) aggregate abundance based management (AABM) fishery and US and Canadian individual stock based management (ISBM) fisheries. The stock has high fishery management importance because of its large exploitation in the WCVI AABM, US ISBM and Canadian ISBM fisheries and large abundance.