Montana Fish, Wildlife and Parks is seeking public comment on an environmental assessment for a project to establish a genetically pure population of westslope cutthroat trout in Ruby Creek, a small tributary of the Madison River south of Ennis.
Westslope cutthroat trout are native to the Missouri River system in Montana and over the years as rainbow, brown and brook trout have been introduced, the cutthroats have lost ground, said area FWP fisheries biologist Pat Clancey.
“They were the only true trout species in the entire Missouri River Drainage in Montana when Lewis and Clark came through here,” Clancey said. “They’re part of Montana’s natural history.”
Westslope cutthroat trout have been nominated for listing as endangered or threatened under the Endangered Species Act twice in the past, he said.
Cutthroat can hybridize with rainbow trout and are susceptible to predation by brown trout, Clancey said. Brook trout can just simply out compete cutthroat for habitat because they are so prolific.
So one of the only ways to bring back pure strains of the fish is to find areas where populations can be isolated, like Ruby Creek, which flows through Wall Creek Wildlife Management Area out of the Gravelly Mountains.
Ruby Creek is unique because a water fall a little more than a half mile upstream from where it hits the Madison River makes fish passage upstream impossible, Clancey said.
From there Ruby Creek holds a population of rainbow trout for about nine miles of river, including about a one-mile stretch of South Fork of Ruby Creek.
The project proposed in FWP’s environmental assessment calls for the removal of all rainbow trout from Ruby Creek above the lower falls both by electroshocking and capture and by the poison rotenone. The plan is to capture fish late this summer and remove as many rainbow trout and sculpin as possible, Clancey said. The trout will be taken to the Madison River and the sculpin will be held off sight to be replaced in the creek later.
Then the stream will be treated with rotenone to remove any remaining fish, he said.
The environmental assessment calls for a possible retreatment in 2013.
Once the existing rainbow trout are released, the creek will be restocked with genetically pure westslope cutthroat trout eggs or young of the year fish, Clancey said.
Currently, the only two wild populations of genetically pure westslope cutthroat trout populations in the Madison River Basin are in and near Yellowstone National Park.
Grayling Creek is in the Montana portion of Yellowstone National Park and Wally McClure Creek is in the Hebgen Basin. Between the two streams, there is about five miles inhabited by cutthroat. This means the Ruby Creek project has the potential to nearly double the existing area in the Madison River Basin inhabited by cutthroat, he said.
A similar project is being wrapped up in Cherry Creek, which is a tributary to the lower Madison River. That project has already led to the presence of some cutthroat trout in the lower Madison River, Clancey said.
Ultimately, that would be one hopeful outcome of the Ruby Creek project – that some cutthroat trout could begin to show up in the Madison River.
Comments about the proposed project can be submitted to Clancey at PO Box 1336, Ennis 59729. Copies of the environmental assessment can be found on the FWP website by going to fwp.mt.gov and clicking on news, then public notices, then species removal and relocation.
Comments on the project will be accepted through 5 p.m. on June 16.