EMPIRE, Colo. - The USDA Forest Service, Colorado Parks and Wildlife, Trout Unlimited, and a host of volunteers stocked 6,000 greenback cutthroat trout fry into Upper West Fork Clear Creek near Jones Pass on Wednesday, Sept. 22.
This is the third location in the Clear Creek drainage where the Greenback Cutthroat Trout Recovery Team has stocked greenbacks into, joining Dry Gulch and Herman Gulch.
“Greenback cutthroat trout reintroductions such as the West Fork Clear Creek are really only able to occur due to the coordination and efforts of each cooperating agency and non-profit partners such as Colorado Parks and Wildlife, Trout Unlimited, US Fish and Wildlife Service, the USDA Forest Service and the Greenback Cutthroat Trout Recovery Team to name a few,” said Valerie Thompson, South Zone Fisheries Biologist for the Forest Service. “Each partner contributes in unique ways that enable the success of major conservation projects such as this one on West Fork Clear Creek, where over fourteen years of stream health data was collected, an old mine site was remediated, and stream banks were restored to allow for habitat that is suitable to sensitive aquatic life and now a new home to the Colorado State Fish, the Greenback Cutthroat Trout.”
The fact that this tributary was fishless to begin with made it a good candidate for the greenbacks, among other factors.
“We’ve done temperature monitoring and the temperatures are conducive to support natural reproduction,” said Paul Winkle, Aquatic Biologist for CPW. “It is a goal to get another population of fish on the landscape, so this is definitely an important thing for the recovery of greenbacks.”
This stretch of stream was fishless due to downstream barriers, such as a quarter-mile-long culvert underneath the Henderson Mine Site, among other natural barriers. That saved some heavy lifting, not requiring a reclamation of the stream to remove other non-native species of fish. Removal of all other species is necessary to ensure the successful reestablishment of greenbacks, which are native to the South Platte River basin.
“We knew that there were no fish in that section of Clear Creek and what a great thing to be able to put fish in without having to do a reclamation,” Winkle said. “The more streams of greenbacks we stock along the Front Range drastically improves the conservation status of the species.”
Today, the greenbacks are listed by the U.S. Fish and Wildlife Service as a threatened species. Greenbacks have previously been stocked into Herman Gulch, Dry Gulch, the East Fork of Roaring Creek and Zimmerman Lake. Those all reside within the South Platte River drainage. The sixth body of water in Colorado where the official state fish currently resides is in Bear Creek outside of Colorado Springs.
These rare fish, twice believed to be extinct, are descendants of the last wild population of native greenback cutthroat trout. Researchers from CU Boulder in partnership with CPW discovered in 2012 that the cutthroat in Bear Creek were the last remaining population of greenback cutthroat trout.
CPW’s Mount Shavano Hatchery in Salida is responsible for rearing and delivering all greenbacks that get stocked. They hatch fertilized eggs in its Isolation Unit. Extra milt collected from male greenbacks in Bear Creek goes to the U.S. Fish and Wildlife Service's Leadville National Fish Hatchery to fertilize eggs from the greenbacks in its brood stock.
The eggs are then taken to Salida to be hatched and eventually stocked onto the landscape at various sizes. Sometimes those fish are of fingerling lengths (one to two inches), sometimes they are fry. Fry is a recently hatched fish that has reached the stage where its yolk-sac has almost disappeared and its swim bladder is operational to the point where the fish can actively feed for itself.
“Trout Unlimited and our West Denver Chapter have a long history of supporting the Forest Service and Colorado Parks and Wildlife in stewardship of the Clear Creek drainage," said David Nickum, executive director of Trout Unlimited. “We are so pleased to see those efforts coming to fruition with our volunteers working side by side with our partners to finally return greenbacks to their home waters in the West Fork headwaters.”