Integrating remote sensing methods to measure baseline behavior and responses of social delphinids to Navy sonar
Abstract
Full Technical Proposal Submitted under: BAA Number 16-001 Integrating remote sensing methods to measure baseline behavior and responses of social delphinids to Navy sonar Abstract Recent experimental studies supported by the Navy have used increasingly high-resolution and multi-sensor measurements to measure detailed, multivariate aspects of behavior in controlled conditions. However, major areas of uncertainty remain, including the response of entire groups of species, such as the social delphinid cetaceans. This results in a significant gap in knowledge that limits the ability of the Navy to accurately predict the potential effects of sonar operations for large numbers of marine mammals. Results from the Southern California Behavioral Response Study (SOCAL-BRS) and earlier studies have demonstrated both categorical differences in the responses of beaked whales relative to other marine mammals and behavioral context differences in the responses of blue whales to controlled exposure experiments (CEEs) using simulated military sonar (e.g., Goldbogen et al., DeRuiter et al., 2013; Friedlaender et al., in press). These studies have provided a strong methodological and analytic foundation for the current project, but also demonstrate that there are significant limitations in directly applying species’ response types and severity to predict the probability, type and severity of potential responses in other marine mammal species that have received little study. Oceanic delphinids (e.g., common dolphins, bottlenose dolphins), at least in U.S. waters, are generally not endangered or threatened, have typically not been observed in mass-stranding events, and some species have been observed behaving apparently normally in the presence of MFAS. However, these anecdotal observations do not necessarily indicate an absence of potential effects and to date there have been no direct experimental studies of the potential responses of these animals in known, controlled conditions. Despite relatively extensive efforts, most previous efforts to deploy high-resolution acoustic and movement tags on smaller delphinids in free-ranging conditions have been generally unsuccessful. Based on pilot field efforts and observations with some of these species in SOCAL-BRS and successful related studies at the Azores, we propose a novel integration of several established remote-sensing methods to directly measure behavioral responses of small delphinids to both simulated and actual MFAS using CEE methods. Specifically, we will utilize complimentary shore- and vessel-based visual sampling, unmanned aerial systems (UAS) for aerial photogrammetry, and remote-deployed passive acoustic sensors to document specific aspects of baseline (undisturbed) behavior and potential responses during sound exposure in common, bottlenose, and Risso’s dolphins. Study objectives include: (1) Develop integrated, cross-disciplinary methods to simultaneously track group movement and behavior using shore- or vessel-based visual observers, aerial photogrammetry, and remote-deployed acoustic recorders; (2) Apply group-sampling methods using these integrated technologies to better characterize the typical behavioral parameters for these species; and (3) Obtain direct measurements of group behavioral changes, if any, resulting from experimentally controlled exposure to simulated and actual Navy MFAS.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2017
- Source ID
- N000141713132
Entities
People
- Brandon L. Southall
Organizations
- Office of Naval Research
- Southall Environmental Associates (United States)
- United States Navy