The Exotic Dilemma: Lessons Learned from Efforts to Recover Native Colorado River Basin Fishes

Authors: Brandon Albrecht, Ron Kegerries, Ron Rogers, Paul Holden

Year: 2018

Abstract

Native fishes of desert aquatic ecosystems have been dramatically impacted by nonnative species. Over time, habitat modification and degradation have set the stage for the influx of many nonnative taxa. Traditionally, nonnative fish control has meant attempting to eliminate every individual nonnative from the habitat of interest. In larger systems, complete elimination has proven impossible, and managers have sought ways for nonnative and native species to coexist or to reduce the stress of nonnative taxa on native species. This paper is the result of a chapter contribution to the new book, Standing Between Life and Extinction, and describes the nonnative fish dilemma, lessons learned, and possible pathways for remediation while providing several examples from the Colorado River basin. We suggest that habitat complexity and more natural flow regimes can help enable native fishes to persist in the face of nonnative fishes. We conclude that a multiplicity of tools, techniques, and education remain important if we are to benefit and maintain our native fish fauna.