Marine mammal passive acoustics applied to the monitoring of long-term trends in beaked whale abundance and to the derivation of a behavioral risk function for exposure to mid-frequency active sonar

Abstract

Knowledge of Cuvier’s (Ziphius cavirostris) and Blainville’s (Mesoplodon densirostris) beaked whales’ distinct dive and vocal behavior has allowed for the development of multiple methods of passive acoustic abundance and density estimation (Marques et al., 2009, Moretti et al., 2010). These methods are being applied to multiple years of data to estimate long-term trends in abundance for Blainville’s beaked whales at the Atlantic Undersea Test and Evaluation Center (AUTEC) in the Bahamas and at the Pacific Missile Range Facility (PMRF) in Hawaii, and for Cuvier’s beaked whales at the Southern California Offshore Range (SCORE). These passive acoustic beaked whale dive data were combined with sonar and Range ship-track data to derive a behavioral risk function for Blainville’s beaked whales at AUTEC, and are being extended to Cuvier’s beaked whales at SCORE and Blainville’s beaked whales at PMRF. The behavioral risk function maps the probability of beaked whale dive disruption as a function of the receive le...