Yellowstone continues to restore native fish with Gibbon River project

Yellowstone continues to restore native fish with Gibbon River project

Source: Bozeman Daily Chronicle
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By Michael Wright

They thought it was a good idea at the time, putting rainbow trout in the upper Gibbon River, the stream that starts in the center of Yellowstone National Park, flows through the Norris Geyser Basin and then joins the Firehole River to form the Madison River.

It was the late 1800s, when Yellowstone’s popularity was growing, and because tourists like to fish, early park managers wanted to make sure they had fish to catch.

And the Gibbon is where that started.

“Rainbow trout above Little Gibbon Falls were the first non-native fish ever stocked to YNP waters,” Todd Koel, Yellowstone’s senior fisheries biologist, said in an email. “Brook trout were stocked to the Gibbon River between Virginia Cascades and Little Gibbon Falls in 1905.”

Now, more than a century later, Koel and his colleagues are going after them. In mid-August, they started treating three lakes and 18 stream miles of the upper Gibbon and its tributaries with the piscicide rotenone to get rid of the non-native fish there. Once that’s over, they’ll bring in native westslope cutthroat and fluvial arctic grayling, two species that used to live there but didn’t fare well when non-natives were stocked.

It’s a continuation of Yellowstone’s quest to restore native fish to certain corners of the park. This will be the second project in recent years where the park tries to restore fluvial arctic grayling, the member of the grayling family that lives in rivers. It’s the fourth project in the last decade to restore westslope cutthroat, a fish often thought of as something only found in western Montana.

Yellowstone’s eponymous cutthroat is often thought of as the main cutthroat species in this region, but the historical range of westslopes actually crossed the Continental Divide. Travis Horton, the Bozeman area fisheries manager for Montana Fish, Wildlife and Parks, said their range even extended to streams in north central Montana mountain ranges. In southwestern Montana, the fish were found in the Gallatin and Madison drainages.

The reason it’s not thought of as the main cutthroat species is that it didn’t survive as well here as it did west of the divide. Non-native fish both crossbred with the species and pushed it from its habitat in many places.

Restoration efforts are starting to change that. Projects in places like Leverich Canyon east of Bozeman and on the Madison River tributary Cherry Creek have preserved habitat for the species.

“We’re far better off than we were 15 to 20 years ago,” Horton said.

The same could be said in Yellowstone National Park. The streams that drain the western side of the park are part of the fish’s historical range, and the park’s 2010 Native Fish Conservation Plan called for restoring them to 125 miles of that habitat.

Koel said in an email that before this Gibbon project, they had restored the species to 46 miles of stream and 49 lake acres. East Fork Specimen Creek, Grayling Creek and the Goose Lake chain of lakes are included in those totals. After the Gibbon project, the numbers will grow to 64 miles and 281 lake acres.

Koel said part of the Gibbon project will only require rotenone treatment this year. Another part will be treated over 2018 and 2019. But once it’s done, the fish will have a cold water refuge that biologists see as increasingly important as the world warms.

In the January 2017 issue of Yellowstone Science, biologists wrote that the upper Gibbon River basin, with its lakes and vast tributary system, is the “largest and most logistically feasible” place for restoring the fish.

“High elevation aquatic systems, such as the upper Gibbon River, may be the only chance to protect sensitive, cold water species such as westslope cutthroat trout and fluvial grayling against climate change,” they wrote.