The Effects of Behavioral Change in Response to Acoustic Disturbance on the Health of the Population of Blainville's Beaked Whales (Mesoplodon densirostris) in the Tongue of the Ocean

Abstract

Abstract : The primary objective of this research is to develop a predictive model for the population health of Blainville's beaked whale (Mesoplodon densirostris, Md) in the Tongue Of The Ocean (TOTO), Bahamas, using data from passive acoustic monitoring collected around and during active sonar operations. MFA sonar operations occur repeatedly on Navy ranges that are known to contain populations of Blainville's and Cuvier's (Ziphius cavirostris, Zc) beaked whales. Strandings of these species have been associated with the use of Navy sonar. A population of Md is known to use the Atlantic Undersea Test and Evaluation Center (AUTEC) range in the Tongue Of The Ocean (TOTO), Bahamas, and a population of Zc has been documented on the Southern California Offshore Range (SCORE) off San Clemente Island in California. Developing a methodology for monitoring the long-term health of populations such as these, which are repeatedly exposed to sonar, is important for the continued operational integrity of these ranges. This research focuses on Md at AUTEC. It combines passive acoustic data from the detection of Md echolocation clicks and sonar; observational data from expert surface observers for group size, surface behavior, and age/sex distribution; biological data from biopsy sampling; precise ship track data from sonar operations; and mid-term (days to months) satellite tag data for animal locations and dives.