Kokanee salmon rebound from dismal numbers in Yukon lake

Staff at Kluane National Park in southwest Yukon are astounded and thrilled by a big rebound in the number of Kokanee salmon in the Park's Kathleen Lake system.

But they're not sure what led to the turn around and are looking for answers, according to biologist Carmen Wong, the ecologist team leader for the Park.

Wong said counts of Kokanee in the lake's spawning beds began in 1976 and averaged about 3,000 fish per year. By 2001, they had declined to several hundred, before almost completely disappearing.

 

"When I started my job in 2008, we actually only counted 20 fish, so if you think about that, that's a huge decline from 3,000 fish to only 20 fish," she said. 

But in 2014, about a thousand salmon were counted, preceding an even bigger rebound last year, when 5,000 were recorded.

"This is a really an incredible story," said Wong. "As a biologist, when you go and only count 20 fish it's pretty dismal. You think that that population is probably going to disappear locally. 

"And when you come back and count several thousand, the place is completely different. The spawning beds are alive, there are eagles flying around, there's traces of eating by grizzly bears, there's wolves hanging 'round.

"So you realize the importance of Kokanee to that little ecosystem."

Kokanee are fresh water salmon genetically similar to sockeye. They were probably landlocked in the Kathleen Lake system by a surging Lowell Glacier, said Wong.

There are just two natural Kokanee populations in Yukon, but several lakes have been stocked with them, she said.

Wong said the Kokanee population seems to be experiencing the same crash and resurgence cycle happening with sockeye salmon. That's led to speculation it's climate related. The Kokanee will be monitored and studied in the coming years looking for relationships between climate, water flows and the population, said Wong.

Possession of the Kokanee has been banned for about ten years, but catch and release is still legal. Wong hopes people sport fishing in the lake will avoid targeting the Kokanee.

"We came from 20 fish and we had several thousand in the last couple years, but that's only two years of good news, so we're not ready to declare this population stable yet," she said.