Fish & Game seeks higher winter pool

SANDPOINT — The Idaho Department of Fish & Game is recommending that Lake Pend Oreille be held at a higher winter pool to capitalize on significant gains in the population of spawning kokanee.

The population of female kokanee is estimated to be about 59,000, said Chip Corsi, Fish & Game’s Panhandle region supervisor.

That tally is below the threshold of 70,000 that helps trigger a winter pool elevation of 2,055 feet above sea level, but the latest estimate is substantially above last year’s estimate, when there were only about 31,000 available spawners.

Corsi said justifications for a higher winter pool include the upward trend of the spawning population, increased survival rates associated with higher winter pools and a forecasted La Niña climate pattern this winter.

“The trajectory of that population is good — it’s going up. Let’s see if we can squeeze a little bit higher egg-to-fry survival out of this and really give that population a boost,” Corsi said.

The recommendation will be forwarded to the Columbia Basin technical management team, a broad consortium of resource managers which helps the U.S. Army Corps of Engineers coordinate dam operations.

The corps announced this week it plans to have the lake drafted to 2,057 feet by Oct. 15. The lake level was at 2,060.91 feet, corps officials at the Albeni Falls Dam said on Thursday.

A final decision in the winter pool elevation is expected by the middle of October.

The winter pool has been held at 2,051 feet for the past two winters, partly because depressed numbers of spawning kokanee, landlocked sockeye salmon which serve as a source of food the lake’s threatened population of native bull trout. Fish & Game typically advocates for a lower lake level when spawning kokanee numbers are down because there is less need for shoreline spawning habitat. Annual fluctuations in winter pool elevations also reshuffle and cleanse the shoreline redds.

The pool elevation over in the previous years can also influence a subsequent year’s winter pool determination, as do the needs of chum salmon in the Columbia River below Bonneville Dam.

Fish & Game hopes the wet La Niña weather pattern, which is expected to persist throughout the winter, will help convince downstream salmon managers there will be enough precipitation to sustain the chum redds on the Columbia.

“(Kokanee) survival rates are best when the lake is up, and this is a year when everything else points to us being able to do that without negative impacts downriver,” said Corsi.