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dc.contributor.authorDeRuiter, Stacy L.  Concept link
dc.coverage.spatialGrand Manan Island, New Brunswick, Canada
dc.coverage.spatialAarhus Bay, Aarhus, Denmark
dc.coverage.spatialGulf of Mexico
dc.date.accessioned2008-12-18T19:11:59Z
dc.date.available2008-12-18T19:11:59Z
dc.date.issued2008-09
dc.identifier.urihttps://hdl.handle.net/1912/2586
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2008.en
dc.description.abstractIn this thesis, I provide quantitative descriptions of toothed whale echolocation and foraging behavior, including assessment of the effects of noise on foraging behavior and the potential influence of ocean acoustic propagation conditions on biosonar detection ranges and whale noise exposure. In addition to presenting some novel basic science findings, the case studies presented in this thesis have implications for future work and for management. In Chapter 2, I describe the application of a modified version of the Dtag to studies of harbor porpoise echolocation behavior. The study results indicate how porpoises vary the rate and level of their echolocation clicks during prey capture events; detail the differences in echolocation behavior between different animals and in response to differences in prey fish; and show that, unlike bats, porpoises continue their echolocation buzz after the moment of prey capture. Chapters 3-4 provide case studies that emphasize the importance of applying realistic models of ocean acoustic propagation in marine mammal studies. These chapters illustrate that, although using geometric spreading approximations to predict communication/target detection ranges or noise exposure levels is appropriate in some cases, it can result in large errors in other cases, particularly in situations where refraction in the water column or multi-path acoustic propagation are significant. Finally, in Chapter 5, I describe two methods for statistical analysis of whale behavior data, the rotation test and a semi-Markov chain model. I apply those methods to test for changes in sperm whale foraging behavior in response to airgun noise exposure. Test results indicate that, despite the low-level exposures experienced by the whales in the study, some (but not all) of them reduced their buzz production rates and altered other foraging behavior parameters in response to the airgun exposure.en
dc.description.sponsorshipWork presented in this thesis was supported by a National Science Foundation Graduate Research Fellowship, the WHOI Ocean Life Institute (Grant Numbers 32031300 and 25051351), the Office of Naval Research, the U.S. Department of the Interior Minerals Management Service (Cooperative Agreement Numbers 1435-01-02-CA-85186 and NA87RJ0445; WHOI Grant Number 15205601), the Industry Research Funding Coalition, and the WHOI/MIT Joint Program in Oceanography/Applied Ocean Science & Engineering (including a Fye Teaching Fellowship).en
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen
dc.relation.ispartofseriesWHOI Thesesen
dc.subjectUnderwater acousticsen_US
dc.subjectMarine mammalsen_US
dc.titleEcholocation-based foraging by harbor porpoises and sperm whales, including effects of noise and acoustic propagationen
dc.typeThesisen
dc.identifier.doi10.1575/1912/2586


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