U.S. Fish and Wildlife Service
134 Union Boulevard
Lakewood, Colorado 80228
May 13, 2009
Contact: Debbie Felker, Recovery Program
303-969-7322, ext. 227
ENDANGERED COLORADO RIVER FISHES ARE REOCCUPYING
HISTORIC HABITAT IN THE COLORADO AND YAMPA RIVERS
LAKEWOOD, Colo. – Biologists conducting research studies in late April for the Upper Colorado River Endangered Fish Recovery Program (Recovery Program) reported the captures of endangered fishes in sections of historic habitat on the Colorado and Yampa rivers where the species had not been collected for decades. A 26-inch, 2 pound, adult male Colorado pikeminnow was captured on April 22, in a 5-mile reach of the Colorado River downstream from the Grand Valley Project Diversion Dam near Grand Junction, Colo.
Until last year, upstream movement of fish into this river section had been blocked since the Price-Stubb Diversion Dam was completed in 1911. In April 2008, this last remaining barrier to fish migration in the Colorado River from Utah’s Lake Powell to the upper end of critical habitat near Rifle, Colo., was removed with the opening of a 900-foot-long fish passage.
“This Colorado pikeminnow is the first of its kind that we’ve detected in that river reach since the fish passage at the Price-Stubb Diversion Dam was constructed,” said U.S. Fish and Wildlife Service (Service) Biologist Bob Burdick. “Additional sampling this spring will help determine if other Colorado pikeminnows are occupying this reach. This Colorado pikeminnow was captured during a research study as part of the Recovery Program’s efforts to estimate population levels for the species.”
Records show this Colorado pikeminnow traveled at least 447 miles during the past 14 years. The wild fish was originally captured in the Green River near Ouray in northeast Utah on May 10, 1995. It was recaptured five more times in various sections of the Colorado River.
“This capture is significant because it demonstrates that since the Recovery Program modified the Price-Stubb Diversion Dam, fish have regained access to historic habitat that was blocked for almost a century,” Burdick said.
Service Biologist Doug Osmundson conducts Colorado pikeminnow population estimates to help evaluate Recovery Program actions to recover the species.
“The fish captured above the Price-Stubb Diversion Dam is one of many Colorado pikeminnows that we have documented moving among Upper Colorado River sub-basins since 1996,” he said. “In this case, the fish traveled at least 254 miles downstream in the Green River to the Colorado/Green River confluence and at least 193 miles upstream into the Colorado River. This movement is an important part of the species’ life history.”
Colorado pikeminnows migrate long distances to and from spawning sites in spring and summer and to reach calmer water in pools and eddies during winter. Early settlers sometimes referred to Colorado pikeminnows as “white salmon” because of their migratory behavior and appearance.
The population of Colorado pikeminnows in the Upper Colorado and Gunnison rivers doubled between 1992 and 2005, increasing from 440 adults in 1992 to 890 in 2005.
On April 28, researchers from Colorado State University’s Larval Fish Laboratory conducting nonnative fish management work for the Recovery Program captured a 17-inch, 1.7 pound, 7-year-old adult razorback sucker in the Yampa River near Lily Park, about 7 miles upstream of Dinosaur National Monument in northwest Colorado. Service biologists stocked this hatchery-raised endangered fish as a 2-year-old juvenile in the Green River near the town of Green River, Utah, in 2004. During the next 5 years, it traveled 280 miles upstream and grew 6 inches.
CSU Biologist John Hawkins has extensive experience studying endangered fishes in the Yampa and other Upper Colorado River Basin (Upper Basin) rivers. “The last time I saw an adult razorback sucker in this section of the Yampa River was almost 30 years ago,” he said. At that time, Hawkins captured two adult razorback suckers at the same location where the fish was found in April.
“The capture of this fish confirms that razorback suckers are reoccupying historic habitat,” he said. “Hopefully, this razorback sucker will gather with others at spawning areas in the Yampa and Green rivers and contribute to recovery of the species.”
Since implementation of the Recovery Program’s 2003 stocking plan, recaptures of stocked razorback suckers have been previously reported in the Colorado, Green and Gunnison rivers of the Upper Basin. Stocked razorback suckers are surviving to sexual maturity, spawning and producing young.
In addition to Colorado pikeminnow and razorback sucker, the Recovery Program is working to recover endangered humpback chub and bonytail in the Upper Basin while water development proceeds in accordance with state and federal laws.
For more information, contact the Recovery Program at 303-969-7322, ext. 227, or visit the Recovery Program’s website at ColoradoRiverRecovery.fws.gov.
The Upper Colorado River Endangered Fish Recovery Program is a cooperative partnership of local, state and federal agencies, water developers, power customers and environmental groups established in 1988 to recover the endangered fishes while water development proceeds in accordance with federal and state laws and interstate compacts.
NOTE TO EDITORS: PHOTOS OF EACH FISH ARE AVAILABLE BY CALLING DEBBIE FELKER AT 303-969-7322, EXT. 227.