1996 Washington, D.C. Briefing Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin

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Fish population status and recovery goals Endangered Colorado River fish (clockwise from top left): Colorado squawfish, humpback chub, bonytail, razorback sucker. Colorado squawfish The largest numbers of Colorado squawfish in the Colorado River Basin are in the Green River. In fact, their numbers in this area actually may be rising. Elsewhere, Colorado squawfish popula- tions are small. They may be declining in the Colorado River and appear stable in the Yampa. Recovery goals for this fish species are to establish naturally self - sustaining populations in the Green River and Colorado River subbasins. Humpback chub In the Green and Yampa rivers, humpback chub populations are very small. A population in the Colorado River near the Utah - Colorado state line is relatively large and appears healthy. Recovery goals are to establish five self - sustaining wild populations and protect their habitat. Primary recov- ery areas in the upper basin include: Black Rocks/Westwater Canyon of the Colorado River near the Colorado/Utah State line; the Yampa and Green rivers in Dinosaur National Monument; Gray and Desolation canyons in the Green River; and Cataract Canyon in the Colorado River. Razorback sucker Most razorbacks captured in recent years in the Green, Colorado and Yampa rivers are thought to be more than 20 years old. There is very little known "recruitment" of young fish into the adult population, meaning few young are surviving to adulthood. Razorback populations are considered critical. The first priority for the razorback is to prevent their extinction in the wild. Bonytail The bonytail is the most endangered of the four listed fish. The last confirmed sighting was in 1981 in the Colorado River near the Colorado -Utah state line. Captive populations of bonytail are being maintained at Dexter National Fish Hatchery in New Mexico and at the Horsethief State Wildlife Area in Colorado. As with the razorback, the primary recovery goal for the bonytail is to prevent extinction in the wild. 15