None supplied. Summary: The general objective of the hydroacoustic study at John Day Dam was to monitor smolt passage into the turbines and spillway. Passage estimates were reported in 'pseudo-real-time,' (27 hr time lapse). Specific objectives were as follows: 1) Determine the hourly estimates of total numbers of juvenile salmonids passing through the powerhouse, spillway, and total project, using single-beam hydroacoustic techniques, 2) Determine how effective the spillway is in bypassing juvenile salmonids, 3) Determine the horizontal and vertical distributions of juvenile salmonid passage into the powerhouse and spillway, 4) Determine weekly estimates of the target strengths of fish, using the dual-beam and deconvolution techniques, at the powerhouse and spillway entrances, and 5) Determine passage rates inside one Turbine 3 intake using hydroacoustic monitoring and correlate these with NMFS airlift samples.