Coho Stock Monitoring and Evaluation

The Nez Perce Tribe developed monitoring and evaluation questions that guide management decisions critical to achieving program goals. Adult, juvenile and hatchery metrics, as reported in this document, adhered to the definitions of the Ad Hoc Supplementation Workgroup performance measures. Each field activity uses standardized protocols developed to ensure that consistent, transparent and high-quality data is collected. Field activity protocols include the objectives and location of each activity, step-by-step guides for proper data collection, minimum quality assurance and control (QA/QC) standards and descriptions of how to record raw data.



Project objectives are as follows:



1. Estimate adult returns of abundance and distribution (adult escapement and distribution, redd surveys, hatchery broodstock, PIT tag detections) to Bonneville Dam, Lower Granite Dam, and upstream tributaries. To determine if adult returns are meeting program benchmarks, division and project staff will collect field data from weirs/traps, passive weirs, in-stream PIT tag detection systems, and spawning ground surveys. We will utilize expanded PIT tag detections at the mainstem Columbia and Snake R dams to estimate an adult return to the basin. Counts of adult coho trapped at the Lapwai Creek, Lostine Rive, Dworshak, and Clear Cr weirs will be used to determine an escapement to those release locations. Spawning ground surveys will be performed with regular surveyed transects and additional transects using a probabilistic-based selection method to determine the distribution of spawning in the Clearwater Basin.



2. Estimate juvenile migration and survival metrics (to and through the Snake and Columbia River hydrosystem. Fish releases at all sites will be evaluated for:

• Emigrant abundance at the release site

• Emigration timing at the release site and Lower Granite Dam

• Travel time from the release site to Lower Granite Dam

• Survival to Lower Granite Dam

• Smolt equivalents to Lower Granite Dam



3. Estimate contributions to ocean, Columbia mainstem, and tributary fisheries. All release groups will be coded wire tagged (CWT) to monitor harvest in commercial, recreational, and tribal fisheries – in the ocean, Columbia River and all tributaries. Clearwater River release groups will be CWT-only and the Lostine River group will be adipose-clipped/CWT. Adults that return to non-target basins may be captured in trapping facilities, and expanded CWT recoveries will estimate straying rates from theses releases.



4. Estimate productivity measures of smolt-to-adult survival, recruit per spawner, an adult-to-adult return rates. Smolt release numbers and adult abundance estimates at various locations (Lower Granite dam, release location weirs/traps) will be used to estimate these metrics.



5. In-hatchery production survival and growth monitoring. Information gathered under this objective is intended to evaluate how well hatchery production techniques are working and whether certain practices can be modified to achieve juvenile performance improvements. The program objectives include developing a localized coho salmon broodstock, optimize hatchery survival, improve juvenile performance and maximize adult returns.



6. Provide pre- and in-season adult run forecasting. Staff will work collaboratively to provide a pre-season adult coho run forecast to the Columbia R Mouth and to Lower Granite dam to assist managers in setting harvest allocations and seasons as well as information for hatchery managers regarding broodstock collection plans. In-season run strength, timing, fish conversions, and abundance will be provided by analyzing PIT tag detections as the adults travel upstream during migration. This real time information will be utilized to manage fisheries and broodstock collection activities. Standardized methods and calculat

The benefit or the program is that coho salmon will restored to sufficient numbers in the Snake river basin to support natural production, as well as tribal and non-tribal harvest. This level of production would provide for the Clearwater broodstock to be naturally, self-sustaining and to provide a run sustaining hatchery supplementation. Our long-term adult return goal for the Snake River is 21,000 coho salmon, breaking it down to 14,000 returning to the Clearwater River and 7,000 to the Lostine River in Oregon. This program with require a substantial hatchery production component and the establishment of highly productive naturally spawning coho salmon to become self-sustaining.