Department of Fisheries Resources Management
Imnaha River Smolt Monitoring Project

The Imnaha Smolt Monitoring Program is an effort to assess the spring out-migration timing, travel time, and relative survival of natural and hatchery steelhead smolts from the Imnaha River to the Snake and Columbia River Dams. The Program began in 1994 as part of the Fish Passage Center ’s smolt monitoring by non-federal entities and continued in 1998 under an umbrella of direct-funds provided by the Bonneville Power Administration for the Nez Perce Tribe.

GOALS

• To provide timely information to the Fish Passage Center that management can use to base in-season water budgets, evaluate spill requests, and monitor general fish health.
• To document migration trends of chinook and steelhead smolts emigrating out of the Imnaha River.
• To estimate survival through the Snake and Columbia River Dams.

• Determine the spring outmigration timing of chinook salmon and steelhead trout smolts collected at the Imnaha River Trap.
• Determine the outmigration timing and travel time of previously PIT tagged wild and hatchery chinook salmon and hatchery steelhead smolts through interrogation from March 15 to June 5.
• Determine the outmigration timing, travel time, and recovery rate of wild and hatchery steelhead PIT tagged from the Imnaha River through the Snake and Columbia River Dams.