Streever, Bill (BP) | Ellison, William T. (Marine Acoustics, Inc.) | Frankel, Adam S. (Marine Acoustics, Inc.) | Racca, Roberto (Jasco Applied Sciences) | Angliss, Robyn (Alaska Fisheries Science Center, NMFS/NOAA) | Clark, Christopher (Cornell University) | Fleishman, Erica (University of California) | Guerra, Melania (Cornell University) | Leu, Matthias (The College of William and Mary) | Oliveira, Shirley (North Slope Borough) | Sformo, Todd (SEA, Inc.) | Southall, Brandon (North Slope Borough) | Suydam, Robert
Most assessments of multiple, interacting, and/or repeated anthropogenic underwater sounds (sometimes considered to be an aspect of cumulative effects assessment) rely on narrative descriptions rather than systematic evaluations. In 2010, recognizing the need to better understand the potential effects of multiple sound sources (such as vessels, drilling rigs, pile drivers and seismic operations), British Petroleum (BP) sponsored the University of California to convene an expert committee tasked with advancing a method of systematic evaluation. The method developed by the committee (1) identifies the species, region, and period to be assessed, (2) compiles data on relevant sound sources for that region and period, (3) models the acoustic footprint of those sources, (4) models the movement of simulated marine mammals (animats) through the acoustic footprint, and (5) aggregates data on sound exposure and movements for each of the simulated animals. The method was applied to a test case or trial loosely based on data from the Alaskan Beaufort Sea during a period of seismic exploration and other activities. Substantial additional work is needed to better define output metrics related to degradation of acoustic habitat and to understand the potential effects of multiple sound sources on individuals and populations. Nevertheless, the method provides a starting point that will lead to improved understanding of the implications of multiple underwater sound sources associated with industrial activities.