Northern pike transfer resuming at Lake Coeur d’Alene
FISHING -- A Lake Coeur d'Alene effort to boost cutthroat trout by transferring northern pike from Windy Bay north to Cougar Bay will resume next week.
The Coeur d’Alene Tribe and Idaho Department of Fish and Game will use gillnets to capture pike in Windy Bay and then transport and release the survivors in Cougar Bay, where biologists say they are less likely to prey on native cutthroat trout.
The project seeks to reduce the number of pike in that south portion of the lake while cutthroat trout are migrating to spawn in Lake Creek, which enters the lake in Windy Bay. Giving more cutthroat a chance to spawn should increase their numbers, biologists say.
Prior to the start of the project last year, researchers found that only about 2 percent of juvenile cutthroat that migrate from Lake Creek to the lake were surviving to return as adults.
The second year of the project will begin Monday, March 14.
Just like last spring, biologists will net, tag and transport northern pike to Cougar Bay over the next six weeks, says a media release from the tribe.
The three-year pilot project was initiated by the tribe last year.
“The idea is to reduce the threat to Lake Creek cutthroat trout, while still allowing anglers an opportunity to fish for and catch the relocated pike,” said Andy Dux, Idaho Fish and Game regional fishery manager.
Cutthroat trout conservation is a priority in tribal and state fishery management plans while Idaho’s plan also calls for providing diverse recreational fishing opportunities in Coeur d’Alene Lake.
Researchers will be watching for pike tagged and released in Cougar Bay last spring to see if they return to Windy Bay.
"The hope is that they have remained on the north end of the lake where fishing pressure is high," the tribe says. "At the end of the three year project, the findings will help to determine if this strategy can be used to reduce the predation threat on cutthroat trout in Windy Bay into the future."
Early results of the study have been encouraging, biologists say.
Last spring, fisheries staff reported capturing 311 northern pike in Windy Bay. They said the vast majority of northern pike in the bay likely were removed. About 25 percent of the captured fish died and the remaining 234 northern pike were transported to Cougar Bay, tagged and released.
Tag returns indicated that anglers caught 32 percent of the transported fish. Most of those fish were caught near Cougar Bay and less than 1 percent has been documented moving back to Windy Bay.
Meanwhile, the numbers of cutthroat in Lake Creek are increasing.
“Cutthroat numbers now average around 300 spawning adults and as many as 8,000 juveniles that move between the stream and lake each year," said Angelo Vitale, the tribe's fisheries program manager.
The tribe offered this background to the project:
Historically, native westslope cutthroat trout were abundant in Lake Creek where many would live as juveniles and then migrate to the lake, where they grew to maturity before returning to the stream as adults to spawn.
A variety of factors, including degraded stream habitat and predation by introduced species in the lake, resulted in a decline in the Lake Creek cutthroat trout population. The Tribe has implemented extensive habitat restoration actions in Lake Creek, improving stream habitat and increasing the number of cutthroat trout that the stream can support.
However, the population is still limited by poor survival within Coeur d’Alene Lake. Estimates indicate that only about 2% of juvenile cutthroat that migrate from Lake Creek to the lake will survive and return as adults. One of the reasons for the poor survival is predation by northern pike, particularly during spring when adult cutthroat swim through Windy Bay on their way to spawn in Lake Creek. Windy Bay provides spawning habitat for northern pike and cutthroat trout are an easy food source in the bay during their spring migration.