West Glacier, MT – Glacier National Park, in partnership with Creston National Fish Hatchery, the U.S. Geological Survey, Montana Fish, Wildlife, and Parks, and the Glacier National Park Conservancy, released thousands of juvenile bull trout into Grace Lake to support the survival of this threatened species in Glacier National Park.
On Monday, June 22, the final 201 juvenile bull trout were flown by helicopter from the Creston Hatchery to Grace Lake where they were dropped from just a few feet from the lake surface using specially designed remote-controlled fish stocking tanks.
The recent fish release was the final stage of a multi-year project in response to broad declines in bull trout numbers on the west side of the park resulting from increased non-native lake trout in park lakes. The project serves multiple objectives including contributing to the mitigation of other bull trout population losses in the park, conserving the genetic diversity of local bull trout populations, establishing a new population of bull trout secure from non-native lake trout, and enhancing the resiliency of park bull trout populations in the face of climate change.
“Glacier National Park and our partners are all committed to conserving native fish in the Flathead River basin,” said Jeff Mow, Park Superintendent. “This is a great example of how much we can accomplish when we work together.”
The project began in 2014 with the capture and relocation to Grace Lake of the last remaining 110 wild juvenile bull trout in Logging Creek. Genetic material suggested this small group of fish came from an estimated two to three parents. This represented the last documented spawning activity in the Logging Lake system. Due to the small number of fish that remained in the system available to start a new population in Grace Lake, a decision was made to supplement this wild fish translocation with bull trout from Quartz Lake, located in the next drainage to the north of Logging Lake.
A total of 27,000 eggs were taken from nine wild female bull trout and fertilized using male bull trout captured on their spawning migration into Quartz Creek from 2016-2018. Biologists carried fertilized eggs in coolers as they hiked six miles of trail before driving the eggs to the Creston Hatchery where they were reared for 6-18 months before being translocated into Grace Lake.
A waterfall downstream from Grace Lake protects the fish from invasive lake trout found lower in the drainage.
From 2017-2020, a total of 4,879 juvenile bull trout ranging in length from two to ten inches were planted into Grace Lake to supplement the earlier wild fish transfer. Grace Lake supports a population of introduced Yellowstone cutthroat trout that serves as the primary food base for the translocated bull trout. Results to date are encouraging. The translocated bull trout are surviving well with some of the initial wild fish having grown from two inches to over 20 inches since being introduced to Grace Lake.
“Helping protect Glacier’s pristine waters and native fish has been, and continues to be a signature project of the Glacier Conservancy. This recent release of bull trout into Grace Lake represents a significant milestone, and we’re honored to be able, thanks to the support of private donors, to support this critical work,” said Doug Mitchell, Executive Director of the Glacier National Park Conservancy.
Biologists will continue to monitor the Grace Lake drainage to determine the long-term success of the project.