Department of Fisheries Resources Management
Johnson Creek Artificial Enhancement Monitoring & Evaluation Project

In the Johnson Creek drainage of Idaho, the Nez Perce Tribe, (NPT) has established a small scale supplementation project to reduce the risk of extirpation of a threatened summer chinook salmon subpopulation. The project has two major components, a supplementation program and a monitoring and evaluation program.

    The supplementation program traps and collects natural adult salmon in Johnson Creek for artificial spawning and rearing. The program, through cooperation with the U.S. Fish and Wildlife Service and Idaho Fish and Game Department, utilizes existing hatchery rearing space at the McCall Fish Hatchery to rear up to 100,000 smolts yearly for release back into Johnson Creek. Adult trapping first began in 1998. The first supplementation smolt releases occurred in 2000 from adults collected in 1998 and releases have continued from 2002 to present.
        This monitoring and evaluation program is a comprehensive evaluation program of both the natural fish and the supplementation fish. This program incorporates a life cycle and life history characteristic approach that monitors the fish from egg to adult to quantify juvenile survival, smolt-to-adult survival return rates, and adult-to-adult ratios. This is accomplished utilizing survival estimation modeling, adult counts, spawning surveys, and genetic analysis. Smolt survival from Johnson Creek to Lower Granite Dam from 1998 to present was 19-24% for supplemented smolts and 38-62% for natural smolts. The first complete cohort of returning supplemented and natural fish completed their adult returns in 2003. Smolt-to-adult return rates (Lower Granite Dam to Johnson Creek) were 2.8% for supplemented fish and 3.6% for natural fish and adult-to-adult estimates were 13.7 for supplementation fish and 8.3 for natural fish.

Publications:
JCAPE Monitoring and Evaluation Plan
JCAPE M&E Summary Report (1998-2005)