Tagging and Playback Studies to Toothed Whales
There has been growing recognition that atypical mass strandings of beaked whales may coincide with naval exercises that use mid-frequency sonar, but the causal chain of events from sound exposure to stranding has not been elucidated. Even less is known about potential risks to other species of odon...
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| Format: | Text |
| Language: | English |
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2011
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| Online Access: | http://www.dtic.mil/docs/citations/ADA598668 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA598668 |
| Summary: | There has been growing recognition that atypical mass strandings of beaked whales may coincide with naval exercises that use mid-frequency sonar, but the causal chain of events from sound exposure to stranding has not been elucidated. Even less is known about potential risks to other species of odontocetes or for other signals. The proposed research is part of a collaborative research program whose long-term goals are to: Compare responses of beaked whales vs other odontocetes to playbacks of mid-frequency sonar sounds vs other anthropogenic signals. Conduct combined visual and acoustic surveys for beaked whales and other cetaceans along with collecting oceanographic data for input into models to predict beaked whale distributions based upon characteristics of their habitats. The ultimate goals will be to predict the distribution of species at risk from sonar, to define dose: response curves for risk to beaked and other whales for exposure to naval sonars, and to suggest improvements for monitoring and mitigation. Ana Ca adas from the Alnilam Marine Research Center describes the habitat modeling efforts in her annual report to ONR as part of this broader program. More playbacks of sonar have been conducted to large delphinids such as pilot whales, Globicephala sp, than to any other species of cetacean, but interpretation of the effect of sonar has been hampered by our lack of understanding of baseline behavior and reasons for behavioral transitions. This project includes two cruises in the Alboran Sea to develop methods to better understand baseline behavior of pilot whales and how they respond to threats. Some delphinids appear to have social defenses against threats in addition to flight reactions, so our work focuses on social behavior and communication in addition to basic transitions of behavioral states. The long term goal of this part of the work is to understand baseline behavior well enough to interpret observed variation in responses to sonar playbacks |
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