Once upon a time, there were enough Arctic grayling in a creek on the western border of Yellowstone National Park that the stream was named for them, Grayling Creek. In the not too distant future, that creek might once again harbor Arctic grayling, as well as native westlope cutthroat trout, under a plan being implemented by park fisheries experts.
Planning for such an attempt actually began back in 2007, when the creek was assessed for its potential of being stocked with the two native fishes. But first the creek had to be cleansed of its non-native brown and rainbow trout. It was the presence of these two species that has contributed to a decline in native cutthroat trout in park lakes, rivers and streams.
This past week an interagency team of biologists began to work on killing the non-native fish by adding a fish toxin into the streams as part of Yellowstone's Native Fish Conservation Plan and Environmental Assessment, which was approved in May 2011. Only waters within Yellowstone National Park are being treated. The project will not impact downstream reaches.
While the chemical Rotenone will be introduced in small quantities, park officials say visitors should not swim in or drink from the streams now through August 30. Warning signs are being posted at all treated areas.
This year's treatment is the first in a series that is expected to continue over the next two to three years, a park release said. Treatments will be conducted until nonnative trout have been completely removed from the streams.
The park will then reintroduce genetically pure native Arctic grayling and westslope cutthroat trout to the streams. The long-term plan is not only to support native species restoration, but also for these streams to provide a brood stock population for future restoration efforts in the region.