Journal of International Wildlife Law and Policy, 9:91–99, 2006 Copyright C  Taylor & Francis Group, LLC ISSN: 1388-0292 print / 1548-1476 online DOI: 10.1080/13880290500536441 A Review of the NRC’s “Marine Mammal Populations and Ocean Noise: Determining When Noise Causes Biologically Significant Effects” Report ANDREW J. WRIGHT 1 In early 2005 the Committee on Characterizing Biologically Significant Marine Mammal Behavior (hereinafter the Committee) published its report, titled “Marine Mammal Populations and Ocean Noise: Determining When Noise Causes Biologically Significant Effects.” 2 The Committee placed the origins of its work in the 2000 U.S. National Research Council (NRC) report, 3 where the term “meaningful disruption of biologically significant activities” was used as part of a description of harassment (see below). Since then, the term ‘biologically significant’ has been used with increasing frequency, without having a clear definition or description. Accordingly, the Committee was tasked as follows: In its 2000 report, Marine Mammals and Low-frequency Sound, the National Research Council recommended that the Marine Mammal Protection Act definition of “Level B harassment should be limited to meaningful disruption of biologically significant activities that could affect demographically important variables such as reproduction and longevity.” Recognizing that the term “biologically significant” is increasingly used in resource management and conservation plans, this study will further describe the scientific basis of the term in the context of marine mammal conservation and management related to ocean noise. Based on input from a scientific workshop, consideration of the relevant literature, and other sources, the committee will produce a brief report that reviews and characterizes the current scientific understanding of when animal behavior modifi- cations induced by transient and non-transient ocean acoustic sources, individually 1 Marine Mammal Scientist, Leviathan Sciences, 3414 N 17th St, Apt. 3, Arlington, VA 22207, USA. Email: marinebrit@netscape.net. The author wishes to thank Chris Parsons, Naomi Rose, ‘Pine’ Eisfeld, and Liz Taylor for their helpful comments on earlier versions of the manuscript. 2 U.S. NATIONAL RESEARCH COUNCIL,MARINE MAMMAL POPULATIONS AND OCEAN NOISE:DETERMINING WHEN NOISE CAUSES BIOLOGICALLY SIGNIFICANT EFFECTS (2005) (NRC, 2005). 3 U.S. NATIONAL RESEARCH COUNCIL,MARINE MAMMALS AND LOW-FREQUENCY SOUND 146 (2000). 91