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Kokanee’s last stand

Fish in hot water as Okanagan Lake’s temperature too high

by Chuck Poulsen
The Daily Courier
Tuesday, October 5, 1999

The weather has been wonderful — except for kokanee looking for cool water in which to spawn.

Kokanee are on the brink of extinction as evidenced by the meager 1,500 that are spawning in Mission Creek. Up to 500,000 had been there in the 1970s.

Now the shore spawners are in danger. The warm summer last year and the warm fall this year aren’t helping either.

Kevin Ade, who is on contract to the Ministry of Environment, as been checking the situation at Bertram Creek and Paul’s Tomb.

He says the water is too warm for spawners, who are expected to start showing up in another week or so.

“The water is much too warm and they won’t come in until it gets cooler,” said Ade. “If it doesn’t cool off, I think they’ll just stay in their depth.”

Ade recorded a temperature of 16 C at Paul’s Tomb on the weekend. The Ministry of Environment’s fisheries biologist Bruce Shepherd said temperatures in the middle of the lake at the surface are 18 – 19 C.

“They’ll need to get down to 10 or 12”, he said.

Last year, following the record hot summer, less than 1,000 shore spawners were counted. This compares with a high of 500,000 in the early ’70s and anywhere from 60,000 to 16,000 through the 90s.

Asked if he thought the kokanee are about to die out in Okanagan Lake, Shepherd said: “It was a disaster last year. We won’t know for a couple of weeks yet, but it’s not looking too good this year.”

He said the problem for the shore spawners has been the premature drawing down of the lake to avoid flood problems and foreshore developments that disturb natural spawning conditions.