Moving Bull Trout Above a Waterfall: How Glacier National Park Directs Change

In Glacier National Park, streams and lakes are warming — and are projected to keep warming — as climate change melts the glaciers and heats the air. At the same time, invasive lake trout (Salvelinus namaycush) have taken over park waters and are wiping out local populations of native bull trout (Salvelinus confluentus), listed as threatened under the Endangered Species Act.

A juvenile bull trout above a juvenile Yellowstone cutthroat trout in Glacier National Park. USGS

Bull trout need the coldest water of any inland salmon or trout species to breed, grow and survive. It became clear that without action they faced not just continued genetic erosion but disappearing from the park altogether.

The move

In Logging Creek, an important bull trout drainage, park staff moved the dwindling population upstream, above an impassable waterfall, into Grace Lake — cooler water, free of lake trout. Grace Lake had already been changed by the past introduction of Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), which don't threaten bull trout.

The park keeps supporting the move by rearing and releasing more fish, monitoring the new population, and evaluating how it relocates them.

Why "direct"

The park accepted that keeping lower Logging Creek's bull trout as they were, where they were, was no longer possible. Instead it directed the change — keeping the species somewhere in the park by moving it to a place it had never lived before. In doing so, it also directed change in upper Logging Creek, an area people had already altered.

The RAD framework

Park managers face growing challenges. Climate change combines with land-use change, more visitors, pollution and nonnative species, pushing ecosystems and park infrastructure beyond their historical range — changes that are increasingly hard to resist. The resist–accept–direct (RAD) framework helps managers make informed, purposeful, strategic choices. It's simple and flexible, complements other climate adaptation approaches, and fits a wide range of decisions:

Watch and read more

Warming up to Adaptation: Glacier National Park (5 minutes, 28 seconds). Bull trout here are threatened by invasive species and warming water; the film shows the bold strategy managers are using to give them better conditions for survival. National Park Service.

National Park Service and U.S. Geological Survey scientists gill-net lake trout in Quartz Lake, part of an effort to remove the species from Glacier National Park. NPS / Jacob Frank.

• Saving Bull Trout — National Park Service
• Translocation of imperiled fishes: conservation introduction of threatened bull trout in Glacier National Park — USGS Northern Rocky Mountain Science Center

Sources

Based on "Glacier National Park Directs Change," National Park Service; a work of the United States government in the public domain.