Northern pike continued their steady advance down the Columbia River this spring.
“It’s been pretty constant,” said Holly McLellan, a fisheries biologist for the Colville Tribe.
In the beginning of May, the Colville, Spokane and Kalispel tribes, alongside the Washington Department of Fish and Wildlife and the public utilities from Grant and Chelan counties, conducted a weeklong suppression effort in Lake Roosevelt.
It was the largest suppression effort undertaken on the lake, McLellan said.
“We wanted to target the pike during their peak spawn and get them before they spawn,” she said.
In the spring, the fish spend the most time in shallow water, making it easier to net them. The nonnative fish are voracious eaters that can, and do, decimate native fish populations. They grow faster than other fish and females can lay more than 10,000 eggs at a time.
The fish have razor-sharp teeth and ambush their prey. Unlike walleye – another nonnative predatory fish – northern pike eat large fish, such as adult salmon.
Managers worry that if pike make it over the Grand Coulee dam, they will decimate already struggling salmon populations. Pike have decimated salmon fisheries in Alaska already.
“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 news release. “If northern pike move downstream, the State of Washington will consider this an environmental emergency. We need to work together to stop northern pike.”
The tribes and state agencies set 475 nets over the course of the week killing 433 pike.
The Colville Tribe and Spokane Tribe start netting in February, but McLellan said the coordinated effort “gave us the ability to have three times more effort in a short period of time.”
The effort “went better than expected,” said Brent Nichols, the Spokane Tribe of Indians fisheries manager.
Still, the fish have made advances since last year when the Colville Tribe caught a pike just 10 miles from Grand Coulee Dam.
As concerned as the co-managers of Roosevelt are about the downstream impact, they’re also worried about the more immediate impact on native fish like redband trout.
Shortly after the weeklong netting effort, the Colville Tribe caught two northern pike – one female with more than 10,000 eggs – in the Sanpoil River arm. The female weighted 28 pounds and was 43 inches long.
The Sanpoil is a spawning ground for redband trout. The trout migrate out of the sanpoil and into the lake proper. McLellan said fishery managers have seen predatory fish sit at the mouth of the Sanpoile, 17 miles from Grand Coulee Dam, and eat around 90 percent of the juvenile trout.
If pike establish themselves in the Sanpoil, it could mean disaster for the redband trout, McLellan said. Luckily, the female was killed before she could release the eggs.
At the end of the day, McLellan thinks the best anyone can do is slow the tide.
“They are expanding downstream,” she said. “We are not going to get every single one of them. We’re hoping that survival through Grand Coulee is low. But the rate they have been moving downstream, we think they are maybe three years away from being down below Chief Joseph Dam.”
Subscribe to the sports newsletter
Get the day’s top sports headlines and breaking news delivered to your inbox by subscribing here.