Management of Smallmouth Bass in the Upper Colorado River Basin: past, present, and future

Authors: Katherine Lawry, Christian Smith

Year: 2024

Abstract

The Upper Colorado River Endangered Fish Recovery Program considers Smallmouth Bass (Micropterus dolomieu) a threat to native fish assemblages and has been implementing efforts to control bass populations for two decades. We provide a comprehensive summary of past and present Smallmouth Bass management actions in the Upper Colorado River Basin with an in-depth look at mechanical and non-mechanical population suppression efforts in the Yampa, Green and White River subbasins. Management actions in all subbasins have largely centered on mechanical removal using electrofishing and have had mixed results. A better understanding of bass movement patterns in the context of environmental conditions, including flow and temperature regimes, may improve efficiency and efficacy of future mechanical removal. Recent use of strategically timed Flaming Gorge Dam flow releases to disadvantage Smallmouth Bass shows promise and needs continued evaluation.