Behavioral Responses of Odontocetes to Playback of Anthropogenic and Natural Sounds

Abstract

Abstract : The long-term goal of this research project is to safely study responses of beaked whales to naval sounds in order to understand the causal chain of events leading from sound exposure to risks of stranding and to measure the exposure required to elicit responses that are safe but indicate potential for risk. The project is designed to provide critical information required to develop measures to protect beaked and other whales from risk of exposure to sonar and other sounds. A critical objective for understanding possible links between sonar exposure and injury or stranding involves developing techniques to safely study how beaked whales respond to sound. This project will establish, test and refine new protocols for studying beaked whales using established sound playback experiment paradigms; define responses of beaked whales and other species of odontocete whales to mid-frequency active (MFA) sonar and natural sounds such as those from killer whales; and measure exposure parameters for sounds that evoke a behavioral response. The approach for this study involves controlled exposures to tagged whales where the scientific team controls the sound source. The WHOI team helped design and plan the study, built, tested and calibrated sound and orientation recording tags (Digital Archival Tag - DTAG), tagged beaked and pilot whales, and is helping to analyze and write up the results. Field efforts were conducted at the Atlantic Undersea Test and Evaluation Center (AUTEC) on Andros Island, Bahamas, adjacent to the deep canyon of the Tongue of the Ocean (TOTO). AUTEC has a 600 square mile, permanent range of 82 bottom mounted hydrophones which can be used for detecting and locating cetaceans on the range using the NUWC marine mammal monitoring equipment. Tagging research has been conducted on this site to establish baseline data and continued collaboration will occur with the Bahamas Marine Mammal Research Organization (BMMRO) for vessels and staff.