Yellowstone’s Elk Creek gets treatment to poison non-native fish

Wildlife biologists in Yellowstone National Park will introduce a fish toxin next week into Elk Creek to remove the non-native brook trout as part of Yellowstone’s Native Fish Conservation Plan and Environmental Assessment, which was approved in May 2011.

Park officials said the project will not impact the nearby Yellowstone River, and is designed to affect Elk Creek and its tributaries, including Lost and Yancey creeks near Tower Junction in the Yellowstone River drainage.

Visitors are advised not to swim in or drink from the streams through September 30, according to a statement released by the park’s public affairs office. Because the chemical rotenone will be introduced in “small quantities,” park officials said warning signs will be posted at all treated areas.

The move is another step in efforts to restore native Yellowstone cutthroat trout in park waters.

Decades ago, National Park Service fisheries managers stocked the streams with non-native brook trout. Their presence has contributed to a decline in native cutthroat trout in these creeks. Brook trout compete with cutthroat trout and often completely displace them and other native fish species.

After all brook trout have been removed, the park will reintroduce genetically pure native Yellowstone cutthroat trout to the streams.

More information on the park’s Native Fish Conservation Plan can be found online at

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