Yellowstone National Park fish biologists will eradicate nonnative brook trout from Elk Creek beginning Monday.

The trout-killing operation, part of the park’s 2011 native fish conservation plan, will be followed by stocking of native Yellowstone cutthroat trout. Elk Creek is a tributary of the Yellowstone River that runs near the Tower-Roosevelt area. Parts of Lost and Yancy Creeks, which feed into Elk, will also have their brook trout population eliminated.

The operation uses rotenone, a piscicide that’s a common tool for biologists trying to clear a waterway of nonnative species as part of restoration efforts, said Yellowstone spokesman Al Nash.

“We have been doing a variety of individual projects over the years,” Nash said. “It’s all focused on protecting our native fisheries and restoring habitats. Historically, a large number of our waterways had nonnative fish planted decades ago with the idea of enhancing the sport fishery.”

Native fish restoration in streams and rivers is often overshadowed by the lake trout removal efforts in Yellowstone Lake, Nash said. However, there are a number of waterways where removal efforts are under way or planned.

An environmental assessment prepared for Yellowstone’s native fish conservation plan shows that Clear Creek, De Lacy Creek, Grayling Creek, Soda Butte Creek, Specimen Creek and the Gibbon River are all scheduled to have their nonnative trout killed. The Goose Lake chain and Pocket Lake will also be treated, the document said.

The Elk Creek treatment will affect about 7 miles of stream; that is estimated to equal a water area of about 1 acre.

The stream will be posted to inform the public what is going on and why, Nash said.

“We post it and there are a variety of other cautions we take any time we use a piscicide,” he said.

At treatment concentrations, rotentone poses no threat to people. The effects on aquatic life outside of fish are “short-term,” the environmental assessment said.

“Amphibians and aquatic macroinvertebrates that are affected by piscicide treatment would be expected to recover completely within three years, and would likely recover more quickly,” the document said.