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

Utah Project

Impacts of Lake Level Elevation Decline on Tui Chub, a Critical Forage Species for Lahontan Cutthroat Trout in Pyramid Lake, Nevada, USA.

May 2023 - September 2025


Participating Agencies

  • U.S. Fish and Wildlife Service, Lahontan National Fish Hatchery Complex
  • US. Fish and Wildlife Service

The importance of tui chub as the primary food source for recovering Lahontan Cutthroat Trout (LCT) in Pyramid Lake, Nevada has been firmly established. However, there is evidence that over the longer term, Tui Chub abundance has been declining, concordant with declines in lake elevation. The mechanism(s) driving this decline remains unknown and could include changes in food availability with changes in lake biogeochemistry, spawning and recruitment failure due to lack of littoral habitat, or a community food-web change. This uncertainty must be addressed in order to ensure the continued recovery of LCT including new natural recruitment, and to assist in determining stocking levels in order to not exceed carrying capacity.
The project being proposed will explore the factors determining food availability for Tui Chub, changes in littoral habitat as they may affect spawning and recruitment success, and potential changes to fish community dynamics, all with consideration of the potential concordant declines in lake elevation.