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Taku River Sockeye Salmon Stock Assessment Review and Updated 1984-2018 Abundance Estimates

author Pestal, G.; Schwarz, C.J.; Clark, R.A.
published year 2020
species sockeye
location Taku River
subjects Transboundary Region, stock assessment, DNA analysis
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Fisheries and Oceans Canada, the Alaska Department of Fish and Game, and the Taku River Tlingit First Nation conducted a review of the Taku River Sockeye Salmon stock assessment program as directed by the Transboundary Panel of the Pacific Salmon Commission. The review was conducted over two years by a working group with representatives from each agency and capture-recapture specialists from both Canada and the U.S. The review focused on compiling, cross-verifying, and analyzing capture-recapture program data from 1984 to 2018.

Tagged fish dropping out of the study and capture gear selectivity were identified as sources of bias in estimating in river abundance, and adjustments were made to each historical annual estimate to account for these. Taku River Sockeye Salmon stock assessment operational plans were improved to minimize and account for these biases. Alternative means of estimating abundance were explored, but we recommend that capture-recapture continue as the primary assessment method. However, a ratio-based estimator using genetic stock identification was identified as having potential for post-season abundance estimates.