Comparative and cumulative energetic costs of odontocete responses to anthropogenic disturbance

Abstract

Abstract : Cetacean responses to marine anthropogenic activities include changes in acoustic behavior, surface active behavior, dive behavior, direction of travel, and behavioral activity states. Behavioral effects have been observed in several field studies involving both observational and controlled exposure experiments. However, the consequences of these behavioral responses are often difficult to quantify in biological currencies. Previous work has empirically measured the energetic consequences of many of these behavioral responses that may have acute or chronic energetic consequences including our ONR-supported work on the metabolic costs of communicative sound and click production, and the metabolic costs of changes in vocal behavior in bottlenose dolphins that are consistent with vocal modification. The current investigation involves two separate but related studies that will address energetic costs of behavioral responses to anthropogenic disturbance, including acoustic effects, in odontocetes. The first study will address, in a comparative framework, metabolic costs of sound production and vocal modification across different sound types and odontocete species. The second component of the investigation will address cumulative energetic costs of behavioral responses to disturbance. These analyses will provide quantitative information that will be particularly useful to incorporate into models such as the Population Consequence of (Acoustic) Disturbance (PCAD/PCoD) as well as provide input data for environmental assessments/impact statements and other permit processes involving anthropogenic activities that have the potential to impact marine mammals.