The Williston Reservoir was created in 1968 following the construction of the WAC Bennett Dam and impounding the Peace River in the canyon near Hudson’s Hope, BC, for hydroelectric generation. With a surface area of 1,779 km2, the Williston Reservoir is the largest lentic freshwater system in British Columbia. A native population of Kokanee, the non-anadromous form of Sockeye Salmon, was found in the Williston Reservoir after completion of the dam. To facilitate the expansion of Kokanee into tributaries of the Williston Reservoir that were more accessible to anglers and provide a prey source for large piscivorous fish species, a stocking program was initiated using fish from the Columbia River. Our analysis revealed that native Williston Reservoir Kokanee diverged from only one of the headwater lake populations and there was no indication of past or current introgression with the introduced Columbia fish. We identified that all spawning Kokanee in tributaries to the reservoir, however, were introduced Columbia-origin fish. As native Williston Kokanee have not been sampled from the reservoir in survey efforts since 2000, it is likely that this population has been extirpated from the reservoir perhaps through competition with the introduced Columbia-origin lineage.

The Natural Resources & Environmental Studies Institute (NRESi) at UNBC hosts a weekly lecture series at the Prince George campus. Anyone from the university or wider community with interest in the topic area is welcome to attend. Presentations are also made available to remote participants through Zoom Webinar. Go to http://www.unbc.ca/nres-institute/colloquium-webcasts to view the presentation remotely.

Past NRESi colloquium presentations and special lectures can be viewed on our video archive, available here.