Tag Archives: Stikine River

Mixed Stock Analysis of Districts 106, 108 and 111 Sockeye

Sockeye runs from the Stikine and Taku rivers in Southeast Alaska are harvested in Canadian aboriginal, recreational, and commercial gillnet fisheries, and in US subsistence, personal use, and commercial gillnet fisheries. In the US, commercial gillnet fisheries in Districts 106 and 108 harvest wild stocks of sockeye salmon bound for Southeast Alaska island and mainland lakes, and for lakes and tributaries in the Stikine, Nass, and Skeena River drainages, while fisheries in District 111 harvest wild stocks of sockeye primarily bound for systems in the Taku River or to Crescent and Speel lakes in Alaska. Significant numbers of enhanced sockeye salmon bound for release sites in the Stikine and Taku rivers or to Snettisham Hatchery are also caught in these fisheries. Catches of Stikine and Taku river sockeye salmon stocks in Districts 106, 108 and 111 gillnet fisheries and the U.S. Stikine subsistence fishery are subject to a harvest sharing agreement outlined in Annex IV of the Pacific Salmon Treaty, in which the US is allowed 50% of the Total Allowable Catch of Stikine River and a variable proportion of Taku River sockeye salmon depending on the return of enhanced fish. Stock contribution estimates are critical to document compliance with the harvest sharing agreements, reconstruct runs of wild stocks, estimate the return of enhanced fish, forecast upcoming returns, and support sustainable management.
Genetic stock identification (GSI) is the preferred method for estimating stock contributions in fisheries in and near the Stikine and Taku rivers, and has been in use for transboundary management since 2011. GSI has improved estimates compared to past methods (scale pattern analysis), and is less logistically complex, less labor intensive, less expensive, more accurate, and delivers more timely results at a finer resolution.
This project has been conducting GSI analysis on sockeye salmon tissue samples collected from commercial gillnet fisheries in areas in and near the Stikine and Taku rivers in Southeast Alaska since 2012. The analysis will be focused on tissue samples collected in Districts 106, 108, and 111.

Transboundary Sockeye Thermal Mark Recovery (ADFG Mark, Tag & Age Lab Support)

The Thermal Mark Laboratory at the ADF&G Mark, Tag and Age (MTA) Laboratory is responsible for examining sockeye salmon otoliths recovered from commercial fisheries in southeast Alaska for thermal marks indicating hatchery origin, and for making the associated data available to biologists for management of sockeye from the transboundary Taku and Stikine Rivers.



Mixed stock analysis of districts 108 and 111 chinook fisheries

The Stikine and Taku rivers in Southeast Alaska (SEAK) support Chinook salmon runs important for various commercial, aboriginal, and recreational fisheries in both the United States (U.S.) and Canada. Included in these are U.S. commercial gillnet fisheries in Alaskan Districts 108 and 111, as well as sport fisheries near Wrangell, Petersburg, and Juneau. U.S. fisheries in these areas harvest stocks of Chinook salmon bound for SEAK and for tributaries in the transboundary Stikine and Taku rivers. Catches of Stikine and Taku river Chinook salmon stocks are subject to a harvest sharing agreement, in which the U.S. and Canada are each given an Allowable Catch specified by the Pacific Salmon Commission, and this relies on catch, escapement, recruitment information, and stock composition estimates to forecast indices of abundance. Until recently, stock composition of harvests was estimated primarily using coded-wire tags, which provided good estimates for marked stocks. However, expansions of these estimates could be uncertain due to a lack of coded-wire tags on all stocks contributing to the fishery, incomplete tagging of index stocks, and in some instances poor estimates of escapement or terminal run size. Genetic stock identification (GSI) provides a complementary set of accurate and reliable stock composition estimates necessary to meet the directives of abundance-based management of Chinook salmon, and is currently used to recalculate actual contributions of above-border Stikine and Taku Chinook salmon to the Districts 108 and 111 sport and commercial fisheries.