Introductions of sockeye salmon into the Okanagan Basin began with the first capture of wild adults for hatchery brood stock in the taking place in the fall of 2003 and hatchery fry intorductions into Skaha Lake have occurred in most years since 2004. The first major introduction of hatchery-origin Sockeye fry (750,000) into Okanagan Lake occurred in spring 2017.
Hatchery-origin adult Sockeye Salmon originating from the spring 2017 introduction returned in small numbers (a few hundred) as adults aggregating below Okanagan Lake Dam in Penticton in 2019 and larger numbers (several thousand) are expected in 2020. Significant numbers of adult returns are also expected in 2021-2022. The Okanagan Lake Dam at Penticton is a barrier to fish passage. The current dam was constructed in 1953 and included a fish-way. However, except for a brief trial period in 2019 the fish-way has never been operated. The effectiveness of the fish-way in supporting adult fish passage remains unknown.
A controlled, trial operation of the fish-way in the Okanagan Lake Dam will be attempted in the fall of 2020 given the expected return of increasing numbers of adult Sockeye in this and subsequent years.
A step-wise approach has been initiated to provide fish passage at Okanagan Lake Dam. The Fish Passage Team/ COBTWG – a tripartite table consisting of the Department of Fisheries and Ocean Canada (DFO), the Okanagan Nation Alliance (ONA) and the Province of British Columbia – approved the project in 2019.
Investigation of Okanagan Lake Dam fish passage options and testing of the fish-way began last fall. Activities proposed for 2020 include: (1) activation of the fish-way to test whether salmonids, including adult salmon, can effectively navigate the ladder and access Okanagan Lake; (2) installation of a trap at the lake-side of the fish-way to control the number and species of fish entering Okanagan Lake; and (3) tagging of 100 adult Sockeye salmon for release into Okanagan Lake. Tagged fish will be monitored and provide information on spawning-site selection, spawn-timing, and interactions with resident stocks. All adult, hatchery-origin Sockeye salmon that are surplus to both brood stock or monitoring needs will support food, social and cultural (FSC) harvest by ONA member nations.
This controlled approach minimizes biological risk to aquatic ecosystems, and provides Provincial, Federal and ONA fisheries staff with data that will inform future management decisions regarding potential impacts to or opportunites for recreational fisheries. Information garnered from fish-passage trials will also inform dam-management and fishway operations by Okanagan Lake Regulation System staff.