SPOKANE - For the second straight year, state and tribal fishery managers are joining forces to remove invasive, non-native northern pike from Box Canyon Reservoir on the Pend Oreille River in northeast Washington.

Starting in early March, crews from the Kalispel Tribe Natural Resources Department (KNRD) will use gillnets to remove pike from the reservoir and will work with the Washington Department of Fish and Wildlife (WDFW) to monitor the results.

"Northern pike are voracious predators that pose a significant threat to native fish species," said Bruce Bolding, WDFW warmwater fish program manager. "They can cause a great deal of ecological and economic damage."

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 decline in abundance of other fish species.

While the 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.

"We're very concerned about the possible spread of northern pike from the Pend Oreille River downstream into the Columbia River, where they could impact salmon and steelhead," said John Whalen, WDFW eastern regional fish program manager.

Under state law, anglers can harvest unlimited numbers of northern pike, regardless of size, year-round. Because they are classified as a prohibited species, they must be dead before they can be removed from any waterway.

While fishery managers encourage anglers to catch all the northern pike they can, gillnetting is the most effective method for pike reduction, Bolding said. Both options were discussed at public meetings conducted by WDFW in 2011 and 2012 to discuss options for removing the invasive fish.

Last year's gillnetting effort removed 5,808 northern pike, while anglers removed another 233 pike during two fishing derbies, said Bolding, noting that the total fell just short of the 87 percent reduction goal.

This year's effort will run through April, followed by an assessment using WDFW's annual Spring Pike Index Netting (SPIN) survey in May. If pike abundance is higher than the target removal number, gillnetting will continue through June, Bolding said.

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.

"Moving live northern pike from one waterway and releasing them in another is illegal because it's highly destructive to other fish communities," he said.

KNRD will conduct a northern pike fishing derby May 17-19 to help reduce numbers. For more information about the event, contact KNRD Fisheries Conservation Program Manager Jason Olson at 509-447-7290.