Concern for West Coast Vancouver Island (WCVI) natural Chinook currently limits PSC fisheries in Southeast Alaska, the Haida Gwaii recreational fishery and particularly the Area F troll fishery in northern British Columbia and troll fisheries and some recreational fisheries on the WCVI. Although the Burman River is enhanced, the population is of sufficient size to estimate the escapement with precision, and thermally marked otolith sampling provides an estimate of the naturally spawned fraction.
The program will estimate the escapement of adult Chinook salmon to the Burman River, a PSC Chinook escapement indicator, using both closed population and open population mark-recapture techniques refined between 2009-2014. The project will also quantify age, sex and origin compositions. Estimates of abundance of the thermally marked hatchery fraction combined with a precise escapement estimate will provide important information to verify and support the WCVI Aggregate ratio estimation project by providing an independent reference point (the Burman River Chinook hatchery fraction, independent of Robertson Creek Hatchery stock) in the northern WCVI area.