Abstract
The objective of the Southern California Behavioral Response Study (SOCAL-BRS) is to determine the effects of mid-frequency (~3 kHz) Navy sonar signals on cetaceans (Southall et al., 2012). Beaked whales are focal species for this study because previous beaked whale strandings have been associated with Navy sonar (Cox et al., 2006). Deep-diving species, such as beaked whales, typically have long dive times and short surfacing intervals, making visual detection difficult. However, beaked whales produce sounds during much of their dive-cycle (53-59%), which provides an alternative means for detecting them (Barlow et al., in press). To increase the probability of detecting beaked whales and improve our ability to track these species once detected, towed hydrophone arrays and improved echolocation click detection software were used for real-time passive acoustic monitoring of cetacean sounds during SOCAL-BRS. This report describes beaked whale detectors and classifiers used during these surveys in the summer and fall of 2012.