Native bull trout reintroduced to Glacier lakes

Native fish, specifically bull trout, have taken it on the chin for many years in Glacier National Park as lake trout took over the park’s waters.

Lake trout, stocked in Flathead Lake more than a century ago, slowly and surely migrated out of the lake and into park waterways. They now occupy 10 of the 17 lakes in the park west of the Continental Divide.

But restoration and lake trout suppressant efforts have created hope that bull trout may still have a healthy future in Glacier.

For the last few years, Glacier Park and the Creston National Fish Hatchery have worked together to preserve bull trout and increase their genetic diversity.

Mark Maskill, the longtime manager at Creston with nearly 40 years on the job with the U.S. Fish and Wildlife Service, explained how he and veteran Glacier Park fisheries biologist Chris Downs have worked together.

“In 2016, things got started when Chris wanted to try something, so we brought back spawned bull trout eggs from Quartz Lake to the hatchery, hatched them and raised the fish here,” Maskill said.

It was done again last year, and a few weeks ago 1,700 bull trout were stocked into Logging and Grace lakes in the park. They included 8-inch yearling trout and 2-inch juveniles. A total of 3,500 bull trout were stocked by helicopter, and one more stocking will be done next year.

Meanwhile, netting efforts in Logging Lake have proven fruitful, greatly reducing the lake trout population.

“Bull trout in Logging Lake are functionally extinct,” Downs said. “There are a few around, but not enough to sustain themselves. Reducing the lake trout population will make it easier for bull trout to re-establish themselves there.”

Grace Lake is a key component in the effort because lake trout can’t get there. It is upstream of Logging Lake and a waterfall prevents any fish from getting there.

Glacier Park fisheries biologists moved about 115 juvenile bull trout out of Logging Lake to Grace Lake in 2014 and with the stockings that have occurred, Downs said things are looking good, so far.

“We’re seeing positive results, but it’s still very early in the process. We believe Grace Lake gives bull trout a high chance of success because they are the dominant predator there and they have a good food source of non-native cutthroat trout,” Downs said. “Time will tell how well it works. We know we can remove lake trout from Logging Lake, but these projects do require quite a bit of money.”

Maskill said if the project can produce a self-sustaining population of bull trout, he believes the park will want to expand it elsewhere.

“It’s been a real nice team effort,” Maskill said. “We work a lot with imperiled fish, like the westslope cutthroat trout, so it’s a natural for us.”

Reporter Scott Shindledecker can be reached at (406) 758-4441 or sshindledecker@dailyinterlake.com.