The centerpiece of the 2008 conservation research will be a genetic study to understand the origins of the fish the make up the South Fork fishery. We will sample fish from the South Fork Boise below Anderson Dam, and the (non-lethal) tissue samples will be used to profile the local rainbow trout population and compare it to an existing library of genetic profiles for wild rainbow trout populations throughout the headwaters of the North, Middle and South Fork of the Boise River.
Analyses of genetic diversity and genetic population structure have become important tools for the recovery and management of recreational species and species of conservation concern. Genetic data can be used to make inferences about populations including extinction risks, migration routes and effective population sizes. Recent advances in analytical approaches also make it possible to address questions focused on the individual. For instance, it is now possible to characterize the genetic fingerprint of an individual and determine the population from which that individual most likely originated by individual assignment.
Individual assignment is well suited for addressing the conservation efforts need to determine likely sources of the large, potentially migratory, individuals observed in the SFB. It is an efficient method for tracking movement in that it does not require actually following the physical movement of individuals, an effort which is often both time and cost-prohibitive. Using individual assignments effectively, however, requires the genetic characterization of all or most potential source populations, and for this foundation we are fortunate to draw from other genetic work already completed within the basin.
For illustrative purposes we show below an example of a color-coded display of genetic information on five different subpopulations of cutthroat trout in northern Nevada.
Scientists with the US Forest Service and Idaho Fish and Game, along with Trout Unlimited have analyzed genetic samples from dozens of rainbow trout populations in the Boise River basin. Other Boise River basin populations have yet to be analyzed. Collectively, this work provides genetic samples from approximately 50 populations in the Boise River (North and Middle Fork), covering a large portion of populations expected as sources of migratory rainbow trout.
The Summer sampling of the South Fork Boise between Arrowrock and Anderson Ranch Reservoirs, and use of the established laboratory protocols and genetic information previously obtained will help determine the likely source populations for the South Fork Boise River fishery. Future sampling from approximately twelve Boise River Basin sites will provide additional SFB population information as to redband migrant recruitment to the river.
Participating local fishing clubs will coordinate a South Fork Boise fishing outing on Saturday, July 12 to collect tissue samples for genetic analysis based on hook & line methods.Volunteers are needed to contribute their angling skills or driftboat use in the name of science!
A base camp for this fish sampling day is planned to be setup at the Reclamation Village area. Participants are welcome to camp in this area and make it a weekend long outing if desired. Look for the TU and BVFF banners to locate the base camp.
Biologists from TU and IDFG will be on hand to instruct anglers how to sample tissue from caught fish, a small fin clip about the size of a spilt shot that is harmless to the fish. Marked envelopes will be provided to anglers to hold the tissue samples and later return to the biologists at the base camp. Measure boards and photo’s will also be used to record statistics of each fish.
Supporters and Anglers are encouraged to participate in our “Adopt-a-Fish” program for $25 per fish. Each contributor may name the fish and receive a simple genetic report about the origins of that fish. Photos and the report will be posted on the Gallery pages later this year or early 2009.
