Development and Implementation of Criteria for Exposure of Western Gray Whales to Oil and Gas Industry Noise

Abstract

AbstractWhether and how noise from human activities adversely affects marine life and what to do to mitigate negative impacts of industrial activities have been subjects of scientific research and regulatory interest for several decades, beginning with the observations of Payne and Webb (1971). In 1995, the US National Marine Fisheries Service (NMFS) began using underwater impulse noise criteria for estimating the physical injury to marine mammals [190 dB re 1 mPa root mean square (RMS) sound pressure levels for pinnipeds and most odontocete cetaceans and 180 dB re 1 mPa for mysticetes and sperm whales]. Subsequently, the High Energy Seismic Survey team (1999) concluded that exposure to air gun pulses with pulse-averaged received levels (RLs) above 180 dB re 1 mPa would likely result in significant behavioral, physiological, and/or hearing impacts. The NMFS has continued to use the 180-dB RL criterion for predicting injury from acoustic exposure for cetaceans and 190-dB RL for pinnipeds as well as a behavioral impact level of 160-dB RL; based primarily on observations of mysticete cetaceans reacting to air gun pulses (e.g., Malme et al. 1984), a 120-dB RL criterion has been applied by the NMFS in some conditions for some nonimpulsive “continuous” industrial noises.KeywordsRoot Mean SquareMarine MammalSeismic SurveyGray WhaleNational Marine Fishery ServiceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.