The Skeena Fisheries Commission (SFC) is made up of five First Nations who do fisheries work within their respective traditional territories in both the Skeena and Nass Watersheds. They include the Gitxsan, Gitanyow, Wet’suwet’en, Lake Babine Nation and Lax Kw’alaams. Currently, both the Gitxsan and Gitanyow conduct annual coho coded-wire tag (CWT) projects in the Skeena Watershed to monitor coho abundance, estimate smolt production, fisheries exploitation and to determine Skeena coho ocean survival. These programs are important because the information collected improves fisheries managers’ abilities to manage coho salmon stocks in the Skeena River by better understanding exploitation rates in U.S. and Canadian fisheries. It also allows managers to determine ocean survival rates for upper and middle Skeena coho stocks because both the Gitxsan and Gitanyow programs accurately enumerate all marked and unmarked returning adult coho annually (fence operations), something that is often not available in many other CWT programs in BC.
SFC is requesting funds from the PSC Northern Fund to purchase CWT equipment. SFC will retain ownership of the equipment in the event that it is decided by SFC commissioners/technical experts that the equipment could be put to better use within one of the other areas where our signatory First Nations conduct works. Any decision to move the equipment for use in another part of the watershed would be done in consultation with the GFA.
Provisions of the 1999 Pacific Salmon Treaty (PST) specify abundance-based 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.
Since 1982, scale pattern analysis (SPA), sometimes in conjunction with other biological markers, has been used to survey the weekly catch of Northern Boundary and Transboundary sockeye salmon stocks in Southeast Alaska fisheries. However, problems in accurately estimating stock-specific catches and total returns of sockeye salmon in the early years of the Pacific Salmon Treaty resulted in an extensive investigation, and it was concluded that improved stock identification techniques, such as genetic stock analysis, were needed to accurately evaluate effectiveness and improve, if possible, existing run reconstruction methods. Two blind tests of scale analysis vs. genetic analysis demonstrated that, while both techniques were accurate, the genetic analysis had higher precision and could also often identify many specific stocks, while scale analysis is limited to identifying a few stock-groups. Neither technique can identify enhanced fish where the brood stock came from wild stocks that are also present in the mixed stock fisheries; thus, otoliths are used in annual stock composition estimates and run reconstructions.
ADF&G proposes to continue collecting weekly otolith, tissue, and scale samples of sockeye from the Southeast Alaska commercial harvest in the District 101 gillnet and District 104 purse seine fisheries, among other districts and fisheries for projects that complement this program. Stock identification analysis using age composition, thermal mark presence, and new, more stock-discrete DNA techniques will be conducted at NOAA’s Auke Bay Laboratory. This project also complements the continuing work by DFO in Areas 3, 4 and 5.
Annual stock-specific run reconstructions (catch plus escapements) are required to accurately estimate relative contribution of each stock caught in Northern Boundary Area fisheries. Estimates of national origin of contributing stocks provides the most reliable information currently available to complete these run reconstructions, and are used to evaluate stock-specific productivity and revise pre-season forecasts. While the catch of Nass and Skeena sockeye salmon is only subject to treaty harvest-sharing annexes in the Alaska District 101 gillnet and Alaska District 104 purse seine fisheries, the harvest of these stocks in all fisheries, and their escapements, needs to be estimated in order to calculate the total run and the percentage caught in the annexed fisheries.
This project will complete genetic stock identification (GSI) analysis on sockeye salmon tissue samples collected from the 2016 commercial purse seine fisheries in Districts 101, 102, and 103 in Southeast Alaska. This project is a complement to the ongoing project at the Auke Bay Laboratory for Northern Boundary Area sockeye salmon GSI in Districts 101 and 104, and continuing work by DFO in Areas 3, 4, and 5; and will allow for complete assessment of the catches of Nass and Skeena sockeye salmon in all major Northern Boundary Area fisheries for run reconstructions. Estimates will be provided for up to 3 time strata in District 101, up to 3 time strata in District 102, and over the entire season in District 103, for a total of 1,500 samples analyzed.