PERSISTENCE OF SMALL POPULATIONS OF BULL TROUT IN IDAHO SUB-ALPINE LAKES”

Project ID: F23AC02261

Federal Agency: U.S. Fish and Wildlife Service

Partner Institution: University of Idaho

Fiscal Year: 2023

Initial Funding: $30,320

Total Funding: $57,599

Principal Investigator: Martonick, Sarah

Agreement Technical Representative: Martonick, Sarah

Abstract: BULL TROUT (SALVELINUS CONFLUENTUS) ARE LISTED AS THREATENED UNDER THE US ENDANGERED SPECIES ACT. ACROSS THE NATIVE RANGE OF BULL TROUT THERE IS CONCERN AS THEIR HABITAT REQUIREMENTS ARE DEGRADED. AS LOWER ELEVATION WATER BODIES WARM DUE TO CLIMATE CHANGE BULL TROUT POPULATIONS WILL INCREASINGLY BECOME ISOLATED. BULL TROUT RESIDING IN SMALL SUB-ALPINE LAKES REPRESENT A UNIQUE LIFE HISTORY FORM THAT IS IMPORTANT TO STUDY CONSIDERING FUTURE HABITAT CHANGES. BECAUSE THESE LAKE COHORTS HAVE BEEN DISCONNECTED FROM ADJACENT POPULATIONS FOR A LONG TIME THEY COULD BE GENETICALLY DIVERGENT. OUR PRELIMINARY INVESTIGATION OF BULL TROUT FROM FISH LAKE IN THE NORTH FORK CLEARWATER RIVER DRAINAGE SHOWS THIS TO BE THE CASE. IN ADDITION, THE EFFECTIVE POPULATION SIZE OF FISH LAKE BULL TROUT IS SMALL, YET THEY HAVE PERSISTED THERE A LONG TIME. THE PURPOSE OF THIS STUDY IS TO IDENTIFY OTHER ISOLATED LAKE POPULATIONS OF BULL TROUT IN IDAHO TO FORM A COLLECTIVE COMPARISON OF GENETIC DIVERSITY. IN ADDITION, THIS STUDY WOULD PROVIDE THE BASIS FOR INVESTIGATING THE MECHANISM FOR HOW THESE POPULATIONS HAVE PERSISTED. LASTLY, THE REPRODUCTIVE BEHAVIOR OF THESE NON-MIGRATORY BULL TROUT WILL BE INVESTIGATED TO UNDERSTAND THEIR SPAWNING BIOLOGY. THIS RESEARCH PROPOSAL WILL PROVIDE IMPORTANT NEW INFORMATION ON THE EVOLUTION OF BULL TROUT GE