Information on the underwater sound generated by operating wave energy converters (WECs) in the open ocean remains limited. The published studies on full-scale devices have been restricted to individual types of WECs and limited by instrument difficulties, providing an inconclusive view of the broad range of possible noise level amplitudes and affected frequencies. The resulting lack of understanding and uncertainty surrounding the potential for acoustic impacts on marine ecosystems from elevated noise levels associated with WEC project activities has brought about a conservative regulatory process for permitting and licensing in U.S. waters. Underwater exposure of living marine resources to anthropogenic sound emissions associated with wave energy development activities is regulated by NOAA’s National Marine Fisheries Service, which currently applies standardized root mean square sound pressure level (SPLrms) threshold noise exceedance criteria to determine WEC project compliance.
The U.S. Northwest National Marine Renewable Energy Center (NNMREC) is currently in the licensing process for a grid-connected, full-scale testing facility known as the South Energy Test Site (SETS) off the central Oregon coast near Newport, OR (Fig. 1) in the Pacific Northwest. The 2.65 square mile area designated for SETS is offshore of the 3-mile territorial state boundary and therefore falls under Federal licensing and permitting regulatory framework. Within that framework, passive acoustic measurements of project noise levels is a key component of the environmental monitoring required for licensing of the facility.