Cooperative Fish and Wildlife Research Units Program: Utah
Education, Research and Technical Assistance for Managing Our Natural Resources

Utah Project

Feeding ecology of Smallmouth Bass Micropterus dolomieu in the White River, UT-CO: quantifying predatory and competitive impacts to native fishes to guide more effective removal efforts.

August 2023 - April 2026


Participating Agencies

  • Utah Division of Wildlife Resources

Smallmouth Bass Micropterus dolomieu are highly invasive in rivers of the Upper Colorado River Basin (UCRB) and are considered a substantial threat to native fish recovery. Smallmouth Bass can negatively impact native fishes through predation and could compete for potentially limiting resources. Quantification of diets is a crucial step to estimate predatory and competitive threats of nonnative fishes, but predicting when and where potential deleterious effects may occur is challenged by spatial and temporal variation in feeding habits and resource availability. The partners are the Utah Division of Wildlife Resources andthe U.S. Fish and Wildlife Service as well as teh Upper Colorado RIver Recovery Program. A more comprehensive assessment of Smallmouth Bass diet in Utah could help identify areas with high incidence of native fish predation or potential competition (if coupled with surveys of availability) to help prioritize intensive removal efforts and aid in conservation of native fishes.