10 Nov One Fish, Two Fish, Red Fish, Kokanee
As fall comes to an end, so does our season of monitoring Shore-Spawning Kokanee (SSK) Salmon at our restoration site. We had another awesome year and we are looking forward to monitoring in the new year.
Kokanee Salmon & Why They Are in Decline
Shoreline Spawning Kokanee numbers in the West Arm are declining (Province of British Columbia, 2021). “Martin (1979) and Andrusak and Northcote (1989) suggest it is attributed to changes in the hydrograph due to hydroelectric operations” (Irvine, Andrusak and Andrusak 2012, p.5). Shore-spawning Kokanee redds become dewatered as lake levels are lowered in early spring, fatally stranding fry on shore.
About the Project:
The Shore-Spawning Kokanee Habitat Restoration & Research Project is a multi-year restoration initiative that takes place on Kootenay Lake. The overarching goal of this project is to reduce the extent of SSK redds and fry that become dewatered each spring due to the drawdown of Kootenay Lake. In September of 2020, we deposited gravel at McDonalds Landing Regional Park in attempt to encourage spawning Kokanee to lay eggs at lower elevations. Throughout the fall, Ministry of Forests, Lands, Natural Resource Operations & Rural Development (FLNRORD) staff monitored spawning Kokanee numbers and behaviour. We later installed egg capsules containing Kokanee eggs at varying elevations within the study and control site. The egg capsules tell us if the gravel is capable of providing suitable habitat for kokanee to develop from egg to fry.
The data we collect is uploaded to the open-sourced Columbia Basin Water Hub, which is accessible to the public. Anyone can access the data to gain a better understanding of local SSK populations and how they change over time.
When we removed the egg capsules in February 2021, we found high egg mortality, indicating that the modified egg capsules disallowed adequate oxygen diffusion. We conducted a dewatered redd survey in March with the ministry of FLRNORD fisheries staff at the restoration site as well as at other spawning sites in the 6-mile area. 80-90% redd dewatering was observed at all sites, except the restored site contained an estimated 70% dewatered redds. Gravel maintenance was performed in April where gravel was raked smooth to reduce clumping and pushed deeper into the water. This reduced gravel pileup on the shoreline and should result in less dewatered redds in 2022. FoKLSS staff and Ministry of FLNRORD fish biologists monitored the restoration site from Sep-Oct, counting the number of spawning kokanee and the number of redds both above and below the low water mark. Seepage metres were placed within the gravel at the study site and tested in preparation for our groundwater monitoring study that will take place over the winter of 2021/22. At the beginning of November, we installed more egg capsules at McDonalds Landing, which will be removed in February 2022 to assess egg-to-fry survival.
2021 was a peak spawning year for Kokanee Salmon. As a result, we noticed a higher number of spawning fish than the previous year. The gravel maintenance completed in the spring has improved the habitat, which was great to see. Redds were easier to spot this year due to sediment deposition and we could clearly see cleaned areas. Spawners appeared to be utilizing the installed/restored substrate even at its lowest depths which is great! It was helpful that the water levels on Kootenay Lake were purposely kept low this year in attempt to benefit spawners (to lessen dewatered redds this upcoming spring).
How You Can Support Local Kokanee Populations:
There are two things you can do to support local Kokanee Salmon populations: become a member of FoKLSS and keep an eye out for redds on the shoreline. When you become a member, you are directly supporting stewardship programs, such as the one above, that enable our staff and team of volunteers to monitor Kokanee populations each year. If you spot spawning Kokanee on the shoreline of Kootenay Lake, let us know by submitting your observations to our Lake Watchers Program.
Read more about how to identify spawning kokanee, where to look, and more here.
Irvine, R.L., G.F. Andrusak, and H. Andrusak. 2012. Assessment of Lake Levels and their Variation on the
Recruitment of Shore Spawning Kokanee Fry within the West Arm of Kootenay Lake. Report prepared for
Columbia Operations Fisheries Advisory Committee.
Province of British Columbia (2021). Kootenay Lake Kokanee Recovery Update.
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