Northern pike are some of the most troubling aquatic invasive species in the Northwest. So far, they haven’t made it past Washington’s Lake Roosevelt. Two dams stand in their way. And lots of people trying to stop them.
If the fish make it past Chief Joseph Dam on the Columbia River, they could greatly harm imperiled salmon downstream.
“In a lot of ways, the fight to save the Columbia River as we know it is going to be won and lost on Lake Roosevelt,” said Justin Bush, executive coordinator of the Washington Invasive Species Council.
American Indian tribes are joining with the state and public utility districts in what’s being billed as the largest coordinated event of its kind in the state. The groups are working for a week to catch northern pike on the lake.
“We are at a critical moment in time where northern pike have not spread into salmon habitat,” said Kelly Susewind, director of the Washington Department of Fish and Wildlife, in a statement. “If northern pike move downstream, the State of Washington will consider this an environmental emergency.”
Northern pike are non-native to the Northwest. They were illegally introduced here in the 1990s and have made their way down the Pend Oreille River into Lake Roosevelt.
They are extremely aggressive and can wipe out fish populations in waters where they aren’t native. In Alaska and California, northern pike have reduced some fish runs so much it’s effectively crashed fisheries, Bush said.
“Northern pike prey on fish that we value, such as trout, salmon and steelhead,” Bush said.
One problem is that Lake Roosevelt is so big (151 miles long) that it makes it hard for biologists to find and kill the invasive fish. Right now, the fish have been spotted about 12 miles from Grand Coulee Dam. That’s 90 miles from where anadromous fish are in the Columbia River, Bush said.
“There have been some new areas found to be colonized within Lake Roosevelt. I think we’re near seeing some really devastating effects within Lake Roosevelt,” Bush said.
In other areas that have faced northern pike problems, fishery communities have “totally flipped in terms of what was present,” Bush said.
Before the fish made it to Lake Roosevelt, they’d invaded the Pend Oreille River. Using gill nets placed in northern pike spawning grounds, the Kalispel Tribe of Indians was able to suppress the northern pike population in that river’s Box Canyon Reservoir.
Officials are asking anglers to report any northern pike they catch and turn them in for a bounty of $10 a head. Reports help biologists know where the fish are in Lake Roosevelt.
Keeping northern pike from reaching salmon habitat could risk billions of dollars that’s been invested in salmon and steelhead recovery, officials said.
“We have been cooperatively working to slow or stop the spread of northern pike, but realize they are poised to continue downstream,” said Dr. Brent Nichols, division director of the Spokane Tribe’s Fisheries and Water Resource Division. “One of the tools in our toolbox is this all-hands-on-deck approach, working with other partners who care about the Columbia River ecosystem.”