The Skeena River Aggregate Coho Salmon Escapement Estimator project is in it’s second year and funded by the Pacific Salmon Commission northern fund. The project is being developed in collaboration with neighboring nations and DFO stock assessment with the primary objective to create a robust watershed-wide escapement estimator for the Skeena River aggregate coho salmon population using genetic tools. To do so, tissue samples are collected from coho caught at the Tyee Test Fishery. Tissue samples are genotyped and assigned to their respective coho population, which allows an estimate of the relative proportion of each population represented in the Tyee Test Fishery sub-sample. The estimate coho escapement from one of these populations, the Bulkley River uses data associated with the existing coho mark-recapture (MR) program at Wiset Canyon. The Bulkley River MR escapement estimate in conjunction with the proportion of coho genotyped at the Tyee Test Fishery assigned to the Bulkley River population may be used to produce an expanded escapement estimate for the Skeena River aggregate coho population.
To improve the use of this approach, GWA has been involved in updating the coho genetic baseline for the Skeena River by increasing the sample size for populations where data is currently insufficient or absent. This will support geneticists at the DFO-Pacific Biological Station update the current baseline to a higher resolution single nucleotide polymorphisms (SNP) baseline, which allows for greater resolution in distinguishing individual populations. In 2019 and 2020 we have made significant progress in closing the gap for the middle and Upper Skeena coho populations with collection made in areas shown on the following map.