This project will provide funding to purchase and apply 15,000 coded wire tags (CWTs) to Zymacord River coho smolts currently being produced by the Northwest Watershed Enhancement Society at the Eby Street Hatchery in Terrace, BC. Tags will be recovered through existing programs in Alaska and northern BC, and analysis and reporting will be provided by DFO’s North Coast Stock Assessment staff.
Coho CWT and exploitation indicators play an important role in our understanding and management of coho in the northern boundary area. The lower Skeena coho have a distinctly different timing (mid-September) compared to the middle and upper Skeena coho (peak August 5th). There is considerable information from previous middle and upper Skeena coho CWTprograms (Babine, Toboggan, Slamgeese and Kitwanga), but there have been no previous CWTprograms for the lower river late-timed stocks. We currently assume the lower Skeena stocks have similar distribution and harvest impacts as the former Lachmach (outside Area 3) and current Zolzap (lower Nass River tributary) stocks.
This project is intended to define harvest patterns of Zymacord River coho in Alaskan and Canadian fisheries that have CWT recovery programs. The program will not include the determination of CWTs in the escapement, and so will not directly provide exploitation rates. However, given the long history from the Skeena and Area 3 and 6 historic and current exploitation rate indicators, the timing and distribution of the harvest CWT recoveries alone are expected to be adequate to define the harvest impacts.