R. C. Tipton and K. J. Hartman, Wildlife & Fisheries Program, Division of Forestry, West Virginia University, P.O. Box 6125, Morgantown, WV 26506-6125

Abstract. Diel hydroacoustic assessment of relative fish densities were performed within the intake lagoon of Bowline power plant, at Stoney Point, New York, and the Hudson River adjacent to the lagoon during July, 1996. We compared fish densities between the two sites to evaluate habitat preferences by fish in the power plant near-field waters vs nearby areas. Information on fish density and distribution near water intakes is important baseline information related to possible impingement and entrainment of fish at plants. A 120 kHz split-beam sounder was used to detect fish every two hours over a 24-h period at four transects running from near-shore to the Hudson River channel and three transects within the lagoon. Midwater trawling was used to partition acoustic targets among fish species. Trawl catch consisted of tom cod, Microgadus tomcod, (67.7%), bay anchovy, Anchoa mitchilli, (20.3%), weakfish, Cynoscion regalis (4.5%), bluefish (Pomatomus saltatrix, (2.3%), white perch, Morone americana, (2.3%), alosids, Alosa sp., (2.3%), and hogchokers, Trinectes maculatus, (0.8%). Relative fish densities were higher within the power plant lagoon. The increased fish densities are believed to be due to the unique and complex habitat found in the lagoon. Although preliminary, these data suggest care should be exercised in siting of future plants in the Hudson River and elsewhere.