Abstract
The development of hydrokinetic energy technologies has raised concern over the potential impacts of underwater noise produced by hydrokinetic turbines on fish species likely to encounter these turbines. To assess the potential for behavioral impacts, redhorse suckers (Moxostoma spp), freshwater drum (Aplondinotus grunniens), largemouth bass (Micropterus salmoides), and rainbow trout (Oncorhyncus mykiss) were exposed to varying intensities of recorded hydrokinetic turbine sounds in a semi-natural environment. Fish were evaluated for differences in mean location during paired noise exposure and control trials; trends in mean fish location were also evaluated during long duration exposure to recordings. Freshwater drum was the only species that showed avoidance behavior during the paired trials. Mixed results were observed for all species in long duration exposures, with no consistent pattern of either attraction of avoidance for any of the four species. Our results suggest that many species may not detect or exhibit response to the sound pressure produced by a single hydrokinetic turbine over a range of distances. However, future research assessing the minimum hearing thresholds of fish likely to encounter deployed hydrokinetic turbines, and the characterization of both the sound produced by different turbine designs and the cumulative sound of turbine arrays would be valuable to further assess potential ecological impacts of hydrokinetic turbine deployment.