Provisions of the Pacific Salmon Treaty specify harvest sharing arrangements of Nass and Skeena River sockeye salmon returns for the U.S. and Canada. The United States is allowed to harvest a fixed percentage of the Annual Allowable Harvest of Nass and Skeena sockeye stocks in Alaska’s District 101 gillnet and District 104 purse seine fisheries. Accurate estimates of the stock-specific catch in commercial fisheries of each nation are required to estimate the total return of these stocks and the percentage of each stock caught in treaty-limited fisheries. Annual catches over or under the agreed percentage are made up for in subsequent years.
Until recently, the Alaska Department of Fish and Game (ADF&G) used scale pattern analysis successfully to estimate contributions of Nass, Skeena and Southeast Alaska sockeye stocks to fisheries in southern Southeast Alaska. From 2006-2015, the Auke Bay Laboratories used genetic analysis for the Northern Boundary sockeye fisheries. Results from comparisons between stock composition using scales and genetic analysis show both methods provide accurate estimates of stock composition, although DNA analysis is able to discriminate stocks at a finer resolution than scales. An additional advantage of the DNA technique is that it does not require annual sampling to re-establish the escapement baseline.
The purpose of this project is to continue the genetic stock identification of the commercial sockeye catch in ADF&G District 101 gillnet fishery and District 104 seine fishery using the baselines developed by the ADF&G.