Juvenile Radio-Tag Study: Lower Granite Dam
Columbia River, handling, John Day Dam, juvenile, Lower Granite Dam, marking, prototype, radio tags, releases, salmonids, Snake River, survival
None supplied. Introduction: The concept of using mass releases of juvenile radio tags represents a new and potentially powerful research tool that could be effectively applied to juvenile salmonid passage problems at dams on the Columbia and Snake Rivers. A system of detector antennas strategically located, that could automatically detect and record individually tagged juvenile salmonids as they pass through the spillway, powerhouse, bypass system, or tailrace areas below the dam would provide an urgently needed research tool. Accurate measurements of spill effectiveness, fish guiding efficiency (FGE), collection efficiency (CE), spillway survival, powerhouse survival, and bypass survival would be possible without handling large numbers of unmarked fish, and because all tagged fish released would in effect be sampled, the numbers of marked fish required for individual experiments could be reduced to a small fraction of those that would be required if conventional marking techniques were used. A prototype juvenile radio-tag system was developed and tested by the National Marine Fisheries Service (NMFS) and Bonneville Power Administration (BPA) at John Day Dam in 1984 (Giorgi and Stuehrenberg 1984). Additional research was conducted at Lower Granite Dam by NMFS and BPA in 1985. The objectives of this research were to: (1) evaluate the effectiveness of the prototype juvenile radio-tag system in a field situation and (2) to test the basic assumptions inherent in using the juvenile radio tag as a research tool. This two-part report summarizes the results of this research.