DEVELOPMENT OF AN INDEX TO MEASURE BODY CONDITION OF FREE-RANGING CETACEANS
Abstract
Marine mammals alter behavior in response to human disturbance, including exposure to sound. Based on this, marine mammal responses to naval sonar could induce missed feeding opportunities and increased activity, which lowers energy intake and increases energy expenditure, respectively. Over the long term, body condition of individuals could decline, which can have profound population consequences. Recently photogrammetric techniques have been used with free-ranging mysticetes where variations in dorsal body widths were examined to assess nutritive condition. It remains to be validated which body component contributed to the measurable changes in body width. Morphological markers to evaluate the body condition of free-ranging, deep-diving odontocetes have yet to be identified. To fill in these knowledge gaps, we will study pilot whales at Sea World San Diego and Orlando for one year to investigate how daily caloric intake and season influences blubber topography, blubber mass, and body mass to identify the site along the body where blubber is most metabolically active in response to energy balance. Ultimately this study will provide a validated, non-invasive tool to measure the body condition of free-ranging odontocetes so that the energetic consequences of sound-induced behavioral changes can be tracked through time. At the same time data on the interrelationship between caloric intake and body condition can be incorporated into models, such as the PCAD model, to estimate the population consequences of sound exposure.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141613129
Entities
People
- Shawn R Noren
Organizations
- Office of Naval Research
- United States Navy
- University of California, Santa Cruz