title: Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines.
abstract: Underwater noise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where sounds created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. A comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6351, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Bevelhimer
authors.affiliation: Energy and Environment Directorate, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K9-33, Richland, Washington 99354, USA.
authors.forename: Z Daniel
authors.initials: ZD
authors.lastname: Deng
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6351, USA.
authors.forename: Constantin
authors.initials: C
authors.lastname: Scherelis
mesh_terms: D000818:Animals; D005399:Fishes / Q000502:physiology; D008922:Mississippi; D009622:Noise; D011210:Power Plants; D045483:Rivers; D012767:Ships; D013018:Sound Spectrography; D014872:Water Movements