Nonnative Fish Control
Nonnative fish have been introduced across the basin, for many years and for many reasons. Predation by nonnative fish species is a serious threat to endangered fishes and perhaps the most challenging to manage. Program partners are using a diverse range of solutions to address this threat, but novel solutions are needed.
The fish pictured in the green rectangle represent nonnative fish introduced into the Colorado River Basin through various means: escapement, illegal introductions and previous stocking. These nonnative fish do not have a serious impact to the native fish.
The blue circle represents the native fish of the Colorado River.
The 3 nonnative fish (smallmouth bass, northern pike and walleye) pictured in the red rectangle are the biggest obstacle to the recovery of rare native fish in the rivers. They eat native fish and compete for habitat and resources.
“The success of the Upper Colorado River and San Juan River Endangered Species recovery programs is vital for Utah’s continued use and development of Utah’s Colorado River apportionment as part of our state’s continued progress in providing for the needs of the citizens of Utah.”
Predation or competition by nonnative fish species is a serious threat to the endangered fishes and perhaps the most challenging to manage. The Recovery Program is working proactively to meet the challenge of nonnative fish management by removing the most problematic nonnative fishes from rivers, and preventing nonnative fish from entering the river system in areas inhabited by endangered fish. The actions recognize the dual responsibilities of state and federal wildlife agencies to conserve native fish species while providing sportfishing opportunities.