CWT monitoring - Pacific Salmon Commission

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.

The Atnarko River was identified as a potential escapement and exploitation rate indicator for Central BC early summer Chinook, and in 2009 the Atnarko River Chinook stock was proposed as an exploitation rate indicator. It was funded under the Coded Wire Tag (CWT) Improvement program, and the purpose of the five-year mark-recapture program was to improve escapement estimates for early summer Chinook.
Since then, the program has met the data standard of a coefficient of variation (CV) of 15% or less. Continued mark-recapture estimates on the Atnarko River will build on the information thus far. The project will estimate the escapement of Chinook salmon and generate estimates such that the fraction of CWT fish is known relative to the wild and/or unmarked escapement, and this data is essential for Chinook run reconstruction calculations. This program is part of a comprehensive group of programs on Atnarko River Chinook salmon that includes the production of Chinook fry and CWT application (under separate submission to the Northern Fund) and terminal fishery monitoring.