Biologists are using a chemical treatment to clear a non-native fish species from a Yellowstone National Park stream.
Soda Butte Creek will close to visitors while staff remove nonnative brook trout.
Park fisheries biologist Todd Koel says the fish compete for resources and threaten to displace the native Yellowstone cutthroat trout, the park’s only native trout species.
“Their young, when they emerge from the gravel in the streams, emerge earlier in the spring, long before any cutthroat trout offspring would, so they have that advantage each year where they can grow to larger sizes faster than the cutthroat trout can,” said Koel.
Seven years have passed since the last effort to clear brook trout from the Soda Butte Creek drainage.
It’s part of continued action to reverse damage from the release of nonnative fish species in the 19th and early 20th centuries.
According to the National Park Service, managers at the time saw wildlife that feed on fish like bears and otters as a nuisance and they populated river systems with nonnative fish for visitors.
Park staff this month temporarily removed Yellowstone cutthroat trout using electroshock in preparation for a chemical treatment called rotenone, used to kill fish.
The stream will be closed from the Northeast Entrance by Silvergate to Ice Box Canyon while agencies administer the treatment between August 14 and 18.
