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Kootenay kokanee stocks in decline

Viral influences are adding to woes for iconic fish

Derek Kaye

Castlegar News contributor

 

Government biologists from the Fish and Wildlife Branch of the Ministry of Forests Lands and Resources have met twice in Castlegar with the West Kootenay Fly Fishing Club three months ago and last week with the Wildlife Club to discuss the decline of Kokanee fish stocks in the Kootenay and Arrow Lakes. The Castlegar News caught up with fly fishing guide Rod Zavaduk who has attended both meetings and although not a trained biologist, has an expert understanding of the local fish life cycles, habitat, and feeding characteristics.

Although the kokanee decline, which is caused by a virus, will be an issue for two or three years before a hopeful recovery, his concerns include the passing of the virus into the rainbow trout population which eat kokanee and the potential for the virus to travel from Kootenay Lake into Kootenay River and eventually the Columbia River where Rod Zavaduk does the majority of his guiding. Kokanee are land-locked sockeye salmon which with the start of dam construction on the Columbia and Kootenay rivers trapped a formerly ocean maturing fish into the Kootenay and Arrow Lakes systems. Kokanee have adapted, to live their entire lives in these fresh water bodies and others such as Okanagan Lake. However, they still live on a two-year life cycle returning to spawn in headwater creeks and rivers that flow into the aforementioned lakes just as sockeye return to spawn every two years on un-dammed ocean flowing rivers.

Rod Zavaduk explained that, “They will make their own recovery when the infected ones die off. As that cycle of infected fish dies off and as long as they do not pass the...virus... to their fry, then the population will rebound.” Because the zooplankton that kokanee eat are mostly  found in lakes and not rivers, kokanee most often remain in that habitat. Not all of the kokanee spawn after two years but some miss their cycle and continue to grow into much larger fish and they advance from zooplankton for food to insects, fish fry and smaller fish.

An interesting development to this story – as the Columbia River Treaty is presently in negotiations for renewal and has the potential for changes and amendments, local Indian bands on both sides of the border are calling for the development of strategies to restore salmon spawning once again in the headwater rivers and creeks of the Columbia River Basin. The technology now exists to allow salmon to continue their upstream movement through the dam system. However, the BC Provincial Government has expressed opposition to this item being on the table in the treaty negotiations. Polling on both sides of the border, however, shows strong interest in favour of salmon once again occupying their historic runs and spawns into this river system.