At the Council and Bonneville Power Administration's request, the ISRP reviewed proposals to design and construct modifications to the Lower Granite Dam Adult Salmonid Trap and for ongoing operation and maintenance of the trap. These facility modifications are intended to improve broodstock collection and reduce risks of straying of fish from outside the Snake River Basin. On January 19, 2005, the Council approved $300,000 in FY 2005 capital funds for the design associated with the improvements at the Lower Granite Dam adult trap, conditioned on the understanding that the ISRP would review the proposal.
Collection and sampling of adult salmonids at Lower Granite Dam is an integral part of many studies. Past operation of the adult trap has been conducted primarily by NOAA Fisheries staff, in cooperation with other agencies. The demands on use of the Lower Granite Dam adult trap have increased in recent years, and are expected to continue to increase. Current uses include fall Chinook broodstock collection, run-reconstruction sampling, sampling of PIT tagged fish from transportation and life history studies, and radio telemetry studies. Expanding the trapping capacity of the Lower Granite Dam adult trap was proposed by the federal Action Agencies in the 2005 Updated Proposed Action to benefit listed ESUs by:
- reducing risks to the Snake River fall Chinook ESU by increasing the ability to collect and incorporate natural-origin broodstock in hatchery programs,
- allowing collection of additional broodstock for use in a hatchery supplementation program in the Clearwater Basin,
- reducing risks to the fall Chinook ESU by increasing ability to remove out-of-basin hatchery strays,
- improving data collection and understanding of ESU status (e.g., run-reconstructions), and
- providing critical fall Chinook life history information (from scale samples) to better manage the stock.