Three northern pike studies that involve gillnetting fish are scheduled this spring on the Pend Oreille River by the Washington Department of Fish and Wildlife and the Kalispel Tribe. The work will be conducted between Newport and Boundary Dam, but primarily in Box Canyon Reservoir:
Spring pike index survey: Starts the last week of April using gillnets in a variety of areas – from the sloughs to the main river channel – to compare with other years to help peg abundance and whether the population is going up or down.
Nets are designed to catch primarily pike with little bi-catch of other species. Researchers used 60 nets last year and caught 755 pike.
Similar surveys are done every year in other waters for trout and walleye.
“This is one way to tell if anglers are catching too many or not enough of a species,” said Marc Divens, WDFW warmwater fisheries research biologist.
“It will help determine the most cost-effective ways for controlling the pike,” he added citing options such as traps, gillnets and bounties.
Some fish are caught, marked and released to provide additional information in recapture studies.
General fishery survey: During a week in mid-May, survey nets designed to catch a variety of species will be deployed along with electro-shocking boats to plot the abundance of all fisheries in the river. The results will be compared with other years to chart the impact pike are having on other species.
Pike location survey: Kalispel Tribe biologists this month launched a pilot project to see where pike spawn and how they move from the river to the sloughs. Gillnets are being placed in two sloughs on one night a week through June.
Results should give biologists an idea of how pike congregate and whether it’s feasible to reduce the pike population to sustainable numbers.
“Last year during spring sampling, we were assuming we’d find a lot more pike in the sloughs than in the river,” Divens said. “But the survey found that wasn’t the case.
“We caught just as many out in the river – almost anywhere out in the reservoir – in relatively similar population levels. So you can’t control pike just by focusing on the sloughs.
“They’re in sloughs seeking warmer water this time of year, for sure, but not all of them, or not all of them at once, and we don’t know what proportion.”