Ten times more “nightmare fish” — northern pike — than last March were caught earlier this month on Lake Roosevelt, including a 20-pound hen carrying eggs that made up roughly a tenth of its body weight.
The unwanted invasive species is the target of stepped-up gillnetting by the Colville and Spokane Tribes, and removal by Washington Department of Fish and Wildlife staffers, who say that this year through March 28, 338 have been taken out of the large reservoir at the head of the Columbia River in Washington.
The worry is that, just as pike got loose out of the Pend Oreille River system into Roosevelt, they’ll get out of FDR and into the salmonid-rich Columbia below Lake Rufus Woods.
Managers are increasing their efforts to head them off as they inexorably move that way.
“To date, northern pike appear to be distributed primarily in the Kettle Falls area — near the mouths of the Colville and Kettle Rivers, Singers Bay, Evans — but juveniles were caught further south, near Bradbury launch, for the first time recently,” says Bill Baker, a WDFW fisheries biologist based in Colville.
He says that 2016 saw recruitment of a “measurable year-class,” along with “confirmed successful spawning” in the Kettle and probably Lake Roosevelt too.
“Many of the northern pike caught thus far this year are from that year class, around 16 to 17 inches on average. However, there are some large adults present, as well,” Baker says.
According to a mid-March Northwest Power and Conservation Council blog by spokesman John Harrison and headlined simply “Nightmare Fish,” the gonads on that hefty hen weighed 2.2 pounds and were “stuffed” with eggs.
WDFW began looking for concentrations of pike in February for the tribes to net this month. Gillnetting now gets ahead of the May-June spawn.
Baker says that this year’s netting effort is larger than 2016’s, so it’s hard to compare overall removal numbers from year to year, but he feels the catch rate is up, probably because of more pike in the lake but also a better understanding of where they like to hang out.
“Last year’s efforts informed where and when to net this year,” he says.
Bycatch has been “low,” he says, with walleye and redband rainbows comprising 8 and 5 percent of the overall haul.
Those fish are released alive as much as possible, and that’s being helped by cold water temperatures, he says.
If there’s good news, it’s that removal efforts in the Pend Oreille River reservoirs by the Kalispel Tribe appear to have pinched off those waters as a source of pike for FDR through entrainment during high-runoff years, such as 2011, when they first came to widespread attention after an angler caught one near Kettle Falls.
But unfortunately, the Canadian Columbia now has established pike schools, and “in-reservoir recruitment appears to now be the major driver for population expansion within Lake Roosevelt,” says Baker.
Northerns likely originally came down the Pend Oreille from the Clark Fork and Northwest Montana, where they were illegally introduced over the continental divide by bucket biologists.
State, tribal and Columbia system overseers are all on board with getting rid of as many pike as possible.
“We need to stop pike from moving downstream now,” Colville Tribes principal biologist Holly McLellan told Harrison, who also quoted Guy Norman, a former WDFW regional director and now member of the power council, as saying, “This is something that could have significant ecological effects on the lake, and on fisheries both in the lake and downriver. We need to get on top of it.”
Not only will putting a halt to northern’s southerly advance down the Columbia system help prevent damage to FDR’s stellar trout, kokanee, walleye and bass fisheries and ESA-listed salmon and steelhead populations below Rufus (the tribes also want to reintroduce stocks above Grand Coulee) but also provide fewer pike for jackasses to illegally move around, like the one that turned up in Lake Washington earlier this winter.
Baker says that gillnetting and monitoring will continue through spring.
And Harrison reports that crews will target the shallows this fall to remove and assess juvenile populations, while eDNA testing stations downstream will tell tribal and state monitors if pike are closing in on Grand Coulee Dam or getting into the Columbia Basin Reclamation Project.