Flathead, Spirit Lakes Chosen For Kokanee Study

Kokanee are the focus of scientific efforts this spring at Montana’s Flathead Lake and Spirit Lake in Idaho.

The Idaho Department of Fish and Game has dropped flashing lights in Spirit Lake in an effort to improve kokanee fishing in Dworshak Reservoir.

Biologists in a boat lower four strobe lights mounted to an anchor into 50 feet of water. A second boat equipped with a sophisticated fish locator monitors whether kokanee are repelled or attracted to the lights.

Fish and Game biologist Melo Maiolie said more than 1 million kokanee were sucked into the spillway of Dworshak Dam last year, seriously damaging the reservoir’s fishery.

If flashing lights repel kokanee, intakes on the dam may be fitted with lights to prevent such heavy fish losses.

“These underwater lights may have other applications, as in keeping fish out of irrigation ditches, pump intakes or other hazardous locations,” Maiolie said.

Spirit Lake was chosen as the test site because it has one of the most concentrated kokanee populations in North Idaho. It also is well protected from strong winds that would make testing difficult on some larger lakes.

“Tests with wild fish in a natural lake should give better results than a test conducted in a hatchery since hatchery fish often behave differently,” Maiolie said.

The tests should not affect fishing in Spirit Lake, he said.

In Montana, fisheries experts this year used a plume of muddy floodwater in Flathead Lake to hide more than 700,000 young kokanee salmon plants from lake trout predators.

State and federal workers last week planted 710,000 kokanee salmon in the lake. On average, the fish were about 6 inches long.

In the past, freshly planted kokanee have been easy prey for the lake’s most plentiful predators, lake trout. But lake trout hunt by sight, and this year’s unusual flood conditions pushed a plume of muddy water into the north end of Flathead Lake.

So biologists planted the salmon in the muddy water, hoping it would hide the kokanee from the lake trout long enough for the young fish to adjust to their new home.

But while the kokanee release went forward on schedule, the experiment in trying to restore kokanee to Flathead Lake faces a doubtful future. Biologists have been frustrated by a lack of return in their kokanee-planting investment.

Kokanee once were the most popular fish with Flathead Lake anglers. But in the 1980s, mysis shrimp were introduced, changing the food chain. Lake trout boomed and kokanee crashed.

Fisheries forum

The Washington Department of Fish and Wildlife (WDFW) and members of the Central Washington Fisheries Advisory Committee will host a public meeting June 12 in Moses Lake to share information about the state’s new warmwater enhancement program.

The 7 p.m. meeting has been scheduled for Frontier Junior High School, 517 W. 3rd St.

Department director Bern Shanks will discuss agency management of warmwater fish species under the 1996 legislation that established the enhancement program and the $5 license surcharge that funds it. The surcharge applies to bass, walleye, channel catfish, crappie and tiger musky.

Bill Zook, the WDFW warmwater program manager, will review current and future spending of fund revenue. Eastside hatcheries manager John Kerwin will report on the Ringold Springs warmwater hatchery. Other fish managers will review historical warmwater fish management in the Columbia Basin, as well as new initiatives and the results of the Moses Lake fish survey.

, DataTimes