South Fork Genetic Study

Back in 2008, after numerous anecdotal reports of fewer fish in the South Fork, Trueblood entered into discussions with Idaho Fish and Game, the Boise National Forest, the Bureau of Reclamation and Boise Valley Fly Fisherman to assess and improve the health of the fishery. This collaboration led to a consensus that the South Fork’s fishery may depend in part on trout likely migrating from other parts of the Boise River watershed.

The Ted Trueblood Chapter was awarded a $6,000 grant from TU’s Embrace-A-Stream program to fund a genetic study rainbow trout in the South Fork of the Boise River below Anderson Ranch Dam.

Trout were caught and a sample taken from the tail with a paper hole puncher.

The overall goal of the South Fork Boise River genetic study was to better understand the life history of the watershed’s fluvial and adfluvial populations of native redband and wild rainbow trout. Results provided useful information on the genetic profile of trout populations in the main river and the tributaries. Secondary results included information on watershed-wide migration habits and possible recruitment from other tributaries throughout the drainage.

July 2008 group photo of fish “sampling” for genetic study

Previous work in the North and Middle forks of the Boise River by TU biologist Helen Neville and others established a baseline of genetic information on the native redband trout in those watersheds. Trout from the South Fork Boise could be compared with some sampling, and on July 12, 2008 more than four dozen participants helped collect fin clip samples.