Battle against invasive northern pike will resume despite dwindling numbers

SPOKANE - State and tribal fish managers are winning the battle against invasive northern pike on a section of the Pend Oreille River in northeast Washington, but they don't expect to declare victory anytime soon.

For the fourth straight year, crews from the Kalispel Tribe Natural Resources Department (KNRD) will use gill nets to remove non-native pike from Box Canyon Reservoir and work with the Washington Department of Fish and Wildlife (WDFW) to monitor the results.

As in previous years, the netting operation will run five days per week through March and April, even though fish managers estimate they have already removed more than 90 percent of the northern pike from the reservoir.

"Northern pike are voracious predators that pose a significant threat to native and game fish species," said Bruce Bolding, WDFW warmwater fish program manager. "We can't stop these fish from moving into Washington waters from Idaho, but we're going to do everything we can to keep their numbers as low as possible."

A key goal is to keep northern pike from moving downstream from the Pend Oreille River into the Columbia River, where they could affect salmon and steelhead populations, Bolding said.

Surveys conducted by WDFW and KNRD between 2004 and 2011 documented a rapid increase in the number of pike in Box Canyon Reservoir and a significant decline in abundance of other fish species.

Bolding said gillnetting during early spring has proven to be the most effective method of reducing northern pike. Between 2012 and 2014, more than 16,000 fish (38,000 pounds) were removed by netting.

In addition, anglers harvested a total of 334 northern pike during "PikePalooza" fishing derbies sponsored by KNRD, which offered more than $20,000 in cash and prizes over the past three years.

Jason Olson, KNRD Fisheries Conservation Program Manager, said the tribe will not conduct similar fishing derbies this year, because the numbers of northern pike have been reduced so far.

"We expect sport angler catch rates for northern pike in Box Canyon Reservoir to remain low," Olson said. "However, bass fishing can be exceptional, and populations of brown trout and panfish are showing signs of rebounding."

State and tribal fishery managers encourage anglers to harvest as many northern pike as they can from both Box Canyon and Boundary reservoirs. Under state law, any northern pike that is caught must be killed before it is removed from the area in which it was taken.

While the Box Canyon Reservoir has the state's largest population of northern pike, anglers have also reported catching them in the Columbia River just north of the Canada border, near Northport and Kettle Falls, and in the Spokane River from Lake Coeur d'Alene in Idaho to Long Lake in Spokane County.

Bolding said problems with northern pike started with illegal releases of the fish into the Flathead, Bitterroot and Clark Fork river systems in Montana, where they migrated downstream into Idaho's Lake Pend Oreille and into Washington.

For more information about northern pike in Washington and annual summaries of the project see http://wdfw.wa.gov/ais/esox_lucius/.