Kokanee headed upstream to spawn and die

The annual migration of Okanagan Lake kokanee into the streams of their birth has begun, but it's not forecast to be a stellar run.

Two kokanee swim upstream to spawn in Mission Creek's spawning channel

Two kokanee swim upstream to spawn in Mission Creek's spawning channel

With a flip of his scarlet tail he launched himself out of the boiling water below the low waterfall and landed with a smack in the still pool above.

He gave himself a shake, fanned his tail for a minute or so, then slowly continued his odyssey upstream.

Behind him, a fellow traveller, also scarlet red with an upcurved green snout, made an attempt at jumping over the falls, but fell back and was carried several yards downstream by the flow of the water.

Eventually he slowed, then reversed and began to work his way back upstream, joined by other spawning kokanee who were on their way from Okanagan Lake up Mission Creek to lay their eggs before dying.

It’s many kilometres of sometimes treacherous water from the lake where they lived and grew for the past three and a half years, up the creek to clean gravel beds where they can lay their eggs to incubate over winter.

In spring, those eggs will turn into small fry that will make the journey in the opposite direction to begin a new life in the big lake, dodging larger fish and other perils to survive.

Kokanee are a land-locked sockeye salmon—a freshwater salmon—and like the saltwater salmon, they spend their adult lives in big bodies of water before returning to the site of their birth to lay their eggs and die, completing their life cycle.

On both trips, upstream as adults and downstream as fry, they are exposed to a variety of hardships, from shallow water, to water that’s too warm; from ducks and osprey to raccoons and bears.

Even as adults in Okanagan Lake, the 20-year Okanagan Lake Action Plan uncovered a myriad of issues that make life difficult for the kokanee, from habitat destruction to nutrient levels in the lake and competition for groceries from an introduced shrimp called Mysis Relicta.

The tiny opossum shrimp were introduced to many interior fishing lakes as feed for trout, but ended up as competition for young kokanee since both feed on the same zooplankton.

The action plan to restore kokanee populations got underway in 1996, following closure of the recreational fishery for kokanee in Okanagan Lake in 1995 to conserve stocks, because of a crash in their populations.

Although efforts to pursue the action plan came to a halt half-way through, a number of changes had been made by then to balance lake levels and improve habitat, as well as reduce mysis populations, and kokanee numbers had gone up enough that a recreational fishery was re-opened last year.

However, early indications are that this may not be a stellar year for the beleaguered fish.

Provincial stock assessment biologist for this region, Paul Askey, says high water temperatures likely stalled some returning kokanee from entering streams as early as in some years, but there is more water than some years in Mission Creek (the largest single producer of stream spawning kokanee for Okanagan Lake), which helps to keep water temperatures cooler and improves habitat for spawners.

This year, he says there appear to be more kokanee returning to the side-channel built for spawning kokanee in 1988, than to the main stem of the creek, perhaps for the first time since it was constructed.

In the past four years, there have been an average of 20,000 returning, although 2009 was a low year, with fewer than 19,000 returning to streams and 140,000 to spawn on shore.

Because that would have been the year this year’s spawners were eggs, it means there’s little likelihood of a large run this year.

It will be another month or so before this year’s shore spawning kokanee begin to head to the stretch of shore where they were born, so Askey had no numbers yet for them.

He said he has heard anglers have been catching big kokanee in Kalamalka Lake this year.

A counting fence has been erected in Middle Vernon Creek to monitor the numbers of kokanee returning from Wood Lake this fall, after a crash in their numbers in 2011 that resulted in a ban on fishing for kokanee in that lake, although there was a six-week opening this summer.

Members of the Oceola Fish and Game Club are helping with that count during the day while contractors continue the task overnight, he said.

He’s optimistic things should improve for Wood Lake anglers by 2016.

Wood Lake is a nutrient-rich little lake, which makes it good fish habitat, but Askey explains it overdid it in 2011 and the decomposing algae ate all the oxygen in the lake, leaving little for fish.

Because kokanee are entering Okanagan streams for their annual migration back to the site of their birth, interpretive programs are offered Saturdays and Sundays at both Hardy Falls Regional Park in Peachland and Mission Creek Regional Park in Kelowna by the Central Okanagan Regional District.

Parks interpreters will be at both parks from noon to 4 p.m. this weekend.





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