Gillnets have removed about 4,000 northern pike from the Box Canyon Reservoir portion of the Pend Oreille River in the second season of efforts to suppress the non-native species and their potential impact to Columbia River salmon.
Crews directed by the Kalispel Tribe and the Washington Department of Fish and Wildlife have been setting 28 to 32 gillnets a day in the river from Newport downstream 55 miles to Box Canyon Dam.
This year’s effort started March 4 and will run five days a week at least through May 3, said Jason Olson, the tribe’s fisheries conservation program manager.
Up to 60 nets a day will be used in the reservoir for the annual fish population survey set for May 6-10.
“If we average more than 1.7 northern pike per net in the southern half of the reservoir or more than 0.5 fish in the northern half, we’ll go back in and net out more pike,” Olson said.
In the past decade, northern pike washing down from illegal introductions in Montana found a Shangri-La in Box Canyon Reservoir. Its riverside sloughs provide ideal spawning rearing habitat for the voracious predators.
After years of research, the state and tribal fisheries staff last year set a target of removing at least 87 percent of the pike from the reservoir.
By reducing the number of pike in this river stretch, the state hopes to give the remaining pike enough hunting room to keep them happy where they are.
“We know we can’t eradicate pike from the river,” said Bill Baker, WDFW district biologist. “But nobody wants them farther downstream into the Columbia. Pike could have a major impact on our investment in salmon and steelhead recovery.”
Last year the suppression effort removed 4,539 northern pike from the river, Olson said.
On April 5, the total removed was 3,818 pike a week beyond the halfway point of this year’s netting.
“We weren’t expecting it, but we caught pike right away last year starting in the middle of March off the edge of the ice,” Olson said. “We started two weeks earlier this year and once again we were catching a lot of pike right away.”
Late winter-early spring is prime time for netting the pike, which spread more widely throughout the river by summer.
Earlier netting effort catches mostly pike with very little “bycatch” of other species.
“The perch and bass haven’t started to spawn, and very few fishermen are out in March,” Olson said.
The gillnetters removed 2,721 northern pike in the first three weeks, he said. The catch declined to about 1,097 pike in the past two weeks.
“Weather could be the reason for the lower numbers or we could be putting a dent in the population; we can’t conclude anything yet,” he said.
The river level has been fairly stable and relatively low compared with last year’s big runoff.
Most of the pike caught have been in the range of 1-3 years, the progeny from the big production years of 2010-2012.
“Most of them were too small to show up in our nets last year,” Olson said. “Hopefully by next year we have a handle on the situation.”
Preliminary numbers indicate the pike being caught are larger for their age than last year’s fish, indicating there are fewer pike and less competition for food, he said.
Recreational anglers targeting pike in the Pend Oreille River this month should focus on the mouth of sloughs and in sloughs, he said: “There seem to be pike in all of them.”
The gillnets have caught several 20 pound pike with the largest being 29 pounds, Olson said.
Last year, anglers caught 233 northern pike in two tribe-sponsored Pikepalooza fishing derbies that were held in summer after the netting operation.
The first of the 2013 Pikepaloozas, with generous cash prizes, is set for May 17-19. Details are on the Kalispel Tribe’s website, kalispeltribe.com.
Contact Rich Landers at (509) 459-5508 or email firstname.lastname@example.org.