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The Mountain-Prairie Region


U.S. Fish and Wildlife Service
134 Union Boulevard
Lakewood, Colorado 80228


April 5, 2004  

Contact:  Debbie Felker, Recovery Program 303-969-7322, ext. 227  
Todd Malmsbury, CO Division of Wildlife303-291-741
Mark Hadley, UT Division of Wildlife,801-538-4737


 LAKEWOOD, Colo. – Management of nonnative northern pike and smallmouth bass remains the focus of research conducted by biologists participating in the Upper Colorado River Endangered Fish Recovery Program (Recovery Program).  This is the second year of concerted efforts to reduce the numbers of certain nonnative fish species in rivers to a level where they no longer threaten the survival of the endangered humpback chub, bonytail, Colorado pikeminnow and razorback sucker. 

 Scientific evidence demonstrates that these nonnative fish species, as well as channel catfish, pose a significant threat to the survival of endangered fish because they prey upon them and compete for food and space.  Declines in other native fish species have also been attributed to increasing nonnative fish abundance.

 “This research will help identify the level of management required to minimize the threat of nonnative fishes to the endangered fishes to satisfy criteria for recovery of these species,” said Recovery Program Director Robert Muth.  “We will assess the data each year to determine future nonnative fish management actions.”

 Efforts will expand from last year to include additional river sections, work crews and removal trips. From April through October, biologists will work in 515 miles of the Colorado, Yampa, Green, and Duschesne rivers in the states of Colorado and Utah.  Depending on the river reach, they will target smallmouth bass and/or northern pike for removal and relocation to area fishing ponds wherever appropriate and practical.

 Although channel catfish were included in last year’s research effort, capture methods proved inadequate for effective removal.  With the exception of Yampa Canyon where effective removal has been demonstrated, channel catfish research has been postponed until sampling efficiency can be improved.

 Sampling protocol has been designed to determine if management efforts reduced the numbers of targeted nonnative fishes in sections where they were removed.  Monitoring of endangered and other native fishes will determine if numbers of these species increase in response to nonnative fish reductions.

This year’s nonnative fish management effort is the largest known riverine project of its kind.  It is a collaborative effort among the Recovery Program, the Colorado Division of Wildlife, the Utah Division of Wildlife Resources, the U.S. Fish and Wildlife Service and biologists from Colorado State University.

 Earlier this year, Recovery Program partners, which include state and federal agencies, environmental groups and water and power user organizations in Colorado, Utah and Wyoming, adopted a policy that addresses the process of identifying and implementing nonnative fish management actions needed to recover the endangered fish.

 “This was a landmark event because it clearly demonstrates that these diverse organizations recognize that management of nonnative fish is essential to achieve and maintain recovery of the endangered fishes,” said U.S. Fish and Wildlife Service Mountain-Prairie Regional Director Ralph Morgenweck, who also chairs the Recovery Program’s Implementation Committee.  “The policy also recognizes the dual responsibilities of state and federal fish and wildlife agencies to conserve listed and other native fish species while providing for recreational fishery opportunities.” 

 Nonnative fish management is only one of several actions the Recovery Program is implementing to recover the endangered fishes. Efforts are also ongoing to provide river flows, restore habitat, construct fish ladders and screens, produce and stock endangered fish and monitor results.

 Established in 1988, the Upper Colorado River Endangered Fish Recovery Program is a voluntary, cooperative program whose purpose is to recover the endangered fishes while water development proceeds in accordance with federal and state laws and interstate compacts.  For more information, call 303-969-7322, ext. 227 or visit the Recovery Program’s website:


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