Assessing nutritional stress and pregnancy in Blainville s beaked whale at the Atlantic Undersea Test and Evaluation Center (AUTEC)
Abstract
To comply with U.S. regulations, the Navy must ensure that testing and training does not negatively affect annual rates of recruitment and survival of potentially impacted populations. This is particularly relevant for beaked whales, which are known to be sensitive to anthropogenic noise, including Navy sonar. Studies at the U.S. Navy s Atlantic Test and Evaluation Center (AUTEC) in the Bahamas indicate that Blainville s beaked whales (Mesoplodon densitrostris) move away from navy sonar sources and are displaced from their regular feeding habitat. Notably, adult females tagged with satellite transmitters at AUTEC ahead of three-day operations using mid-frequency active sonar have shown responsive movements over tens of km away from the AUTEC range. To help investigate the likelihood that their activities are impacting recruitment and survival of marine mammal species with particular focus on M. densitrostris, U.S. Navy has supported the development of the Population Consequences of Disturbance (PCoD) analysis framework, designed to trace the effects of disturbance through life functions to population status. However, key steps of this model can be difficult to observe and accurately parameterize, particularly for cryptic species like beaked whales. To date, these constraints have prevented a direct assessment of whether disturbance is a realistic mechanism for population-level responses to Navy activities. There are now research tools available that can be used to help fill these key data gaps, such as UAS (unmanned aircraft system) aerial photogrammetry and endocrine analysis of blubber samples. We propose to combine UAS photogrammetry, photo-identification, and blubber hormone measures to examine nutritional stress and pregnancies in M. densirostis at AUTEC (and reference areas off Abaco Island), through three key objectives: 1) to assess nutrional stress from biochemical and hormone measures, with a particular focus on adult females, 2) to conduct hormone-derived identification of reproductive status of sampled individuals and 3) combine these biochemical and hormone data with those aerial photogrammetry and photo-identification data to provide a more comprehensive assessment of nutritional state and make estimates of reproductive-loss rate as a function of nutrional state.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 08, 2020
- Source ID
- N000142012291
Entities
People
- Brandon L. Southall
Organizations
- Office of Naval Research
- Southall Environmental Associates (United States)
- United States Navy