By Emily Wolfe Explore Big Sky Managing Editor
BIG SKY – Cooperation is the name of the game, if the native westslope cutthroat trout are to see a successful restoration in one local waterway.
Crews have been working on a project in the Beehive drainage this summer, removing nonnative Yellowstone cutthroat trout from an alpine lake and from parts of the creek that drains from it.
The effort was part of joint project between the Forest Service and the Fish, Wildlife and Parks to restore native westslope cutthroat after Forest biologists found them living there in 2009.
Westslope cutthroat trout – or WCT for short – once populated 1,030 miles of river in the Gallatin River Basin, but today inhabit only 10 percent due to habitat degradation, hybridization with rainbow and Yellowstone cutthroat trout, and competition and predation by brown and brook trout.
The Beehive westslope population was inadvertently protected by an incorrectly installed culvert near the Forest Service boundary that prevented most other fish from passing upstream. The WCT there are hybridized with rainbows, but at less than 1 percent they warranted protection.
“Anytime we find genetically pure or slightly hybridized westslope cutthroat trout in the Gallatin Drainage, that’s a big thing,” said Bruce Roberts, District Fisheries Biologist for the Gallatin National Forest, who was there during the initial discovery.
Late this summer, joint FWP/F.S. crews worked in upper Beehive Basin Creek above Highway 64, and in the lake colloquially known as Egg Lake, in Beehive Basin, removing the non-natives. In the creek, they used electrofishing to remove brook and rainbow, Roberts said, returning the WCT to the creek. In the lake, they used gill nets to remove the Yellowstone cutthroat previously stocked there.
“We didn’t get, nor did we intend to get, all of them this year,” Roberts said. “But we did reduce them substantially.” The project will likely take 2-4 years, he said, and extends to several other drainages in the greater Gallatin River Basin.
Eventually, Roberts said, the plan is to stock the lake with WCT from downstream and from non-hybridized sources in the Gallatin drainage, boosting the genetic diversity of the population.
“In order to have this population exist, it needs to stay in isolation,” Roberts said. “We were hoping the highway culvert was indeed a barrier that closed the system – and it has, mostly – but [this summer] we found that some fish are negotiating that culvert…We have to figure out a way to close the system.”
The highlight of the project for Roberts has been coordinating with local landowners – something he’s been working on for two years.
“To pull this off, we had to coordinate with 14 different landowners because the heart and soul of this westslope cutthroat population is on private land. Those landowners have been incredible.”