Northeast Washington’s Kalispel Tribe has mounted an effort to turn back a wave of invasive northern pike that has devastated local fish populations and warns that other areas of the Columbia River basin could suffer the same consequence.
The tribe’s executive director for Natural Resources, Deane Osterman, during a presentation this month to the Northwest Power and Conservation Council said that the introduction of northern pike to Box Canyon reservoir on the Pend Oreille River has quickly become “a long-term disaster to our native fisheries.”
He urged vigilance because the pike pose significant risks to anadromous salmon and steelhead farther down the Columbia River system.
“Northern pike are a threat to the rest of the Columbia River basin,” he said. He cited reports that the voracious predatory fish have been found in Lake Roosevelt, the central Washington reservoir backed up by Grand Coulee Dam on the Columbia.
Not far downstream is the Columbia’s confluence with the Okanogan River, where much time and money is being spent to revive salmon and steelhead populations.
“That particular piece of water is ideal as well” for nonnative pike to flourish, Osterman said. If pike got a foothold there, they very well could tarnish salmon recovery investments made by the Bonneville Power Administration and channeled through the Council to the Colville Tribes. BPA funds the NPCC’s Columbia River Basin Fish and Wildlife Program as mitigation for impact of the federal Columbia-Snake river hydro system on fish and wildlife.
Other sites, such as the John Day Dam’s reservoir on the lower Columbia, with its warm summertime temperatures and slow moving waters, would also likely be a friendly place for the northern pike.
“John Day pool has ideal habitat for northern pike,” Osterman said.
It is believed the pike were moved downstream from Montana’s Clark Fork-Flathead system, where they were initially introduced illegally in the 1970s or 1980s. The pike were likely flushed down the Clark Fork, into north Idaho’s Lake Pend Oreille, and then into its outlet, the Pend Oreille River, during the flooding in 1997 that resulted from the meltdown of one of the biggest snowpacks on record.
Flows that year at Box Canyon reach 132,000 cubic feet per second, which compares 102 kcfs during what was another extremely high water year this year.
“We’re worried we’ve moved an issue downstream,” Osterman said. “High water events tend to move these fish around. The Pend Oreille flows north into British Columbia briefly then turns west and flows into the southbound Columbia.
Fish managers need to “quickly and efficiently eradicate” any new populations that are discovered, Osterman said.
The impacts in Box Canyon have been startling for a number of reasons. The pike population in the 57-mile-long reservoir have spiked from about 300 in 2004 to more than 10,000 this year. Conversely, native populations such as peamouth have declined by more than 50 percent, Osterman said. Native fish include bull and westslope cutthroat trout, mountain whitefish, largescale and longnose suckers, northern pikeminnow, peamouth, redside shiner, lake chub and sculpin.
Along the way the number of fishing hours on the reservoir jumped from about 400 in 1990 to 76,000 in 2010. The vast majority of those hours were spent chasing northern pike that often weighed in at 20 pounds or more.
“It’s been a boon for the local sport fishing economy,” Osterman said. But, he said, even in an area starved for angler opportunity, “this is not the right opportunity.”
And as the pike population grew, “we started to have stunting issues,” Osterman said. He called it a compensatory response due to lack of prey. That resulted in fewer big fish, and many more smaller fish that still eat native species but are not as desirable for anglers.
“The glory days of trophy northern pike fishing are behind us,” he told the Council.
“They are an incredibly deadly recent invader in Box Canyon,” he said. The pike have undermined significant investments by the tribe, the state, federal agencies and private utilities to restore native species, including bull trout, which are listed under the Endangered Species Act.
More than $500 million has been poured into Pend Oreille River native species restoration such as fish passage, artificial production, and habitat restoration.
The marked increase in angler effort alone cannot control or reverse the expansion in the northern pike population. Osterman said tribal biologists have estimated that at least 500,000 fishing hours would be needed to reduce and stabilize the pike population.
He said with an all-out effort the tribe felt the pike population could be brought down to a manageable level within three or four years.
“We can’t get enough anglers, we can’t get enough boats,” Osterman said. The Kalispel Tribe has proposed a suite of measures to combat the pike invasion in the Columbia basin, asking that the states declassify the species as a gamefish and designate it as an invasive species.
Osterman said catch regulations should be liberalized and require retention of any pike that are landed. The tribe also plans to promote harvest through derbies and tournaments, education and outreach to both the public and elected officials in the Northwest, and the implementation of a long-term mechanical control/suppression program.