K. J. Hartman, T. Bassista, B. Nagy, R. C. Tipton. Wildlife & Fisheries Program, Division of Forestry, West Virginia University, PO Box 6125, Morgantown, WV 26506-6125 and F. Jernejcic, West Virginia Division of Natural Resources, Wildlife Resources Section, 1304 Goose Run Road, Fairmont, WV 26554-1392, and S. Morrison, West Virginia Division of Natural Resources, 2311 Ohio Avenue, Parkersburg, WV 26101

Abstract. On September 16-18, 1997, we conducted a hydroacoustic survey of 3 locks along the West Virginia border of the Ohio River in conjunction with annual lock rotenone sampling. After lock doors were closed, but before rotenone was applied, we used a 120 kHz split beam hydroacoustic system to estimate the abundance and sizes of fish trapped in the Pike Island, Willows Island, and Racine locks of the Ohio River. Subsequent processing of rotenoned fish provided estimates of the species composition, abundance, and size of fish in the lock for comparison with the hydroacoustics estimates. Relative fish abundance from both sampling techniques were in agreement. Highest fish densities were in the Pike Island lock due to high abundances of age-0 gizzard shad Dorsoma cepedianum and skipjack herring Alosa chrysochloris. Lower densities of these clupeids in the other 2 locks resulted in much lower estimates of fish densities. Size estimates from the acoustics and direct measurements also agreed closely. This study represents the first of its kind in which near total measurements of fish in an area have been made for validation of hydroacoustic techniques. The success of this study suggests that mobile hydroacoustic surveys of the Ohio River will also likely be successful in estimating seasonal and annual changes in fish abundance and distribution.