Marine Mammals: Hearing and Echolocation at Coconut Island
HAWAII INST OF MARINE BIOLOGY KAILUA HI MARINE MAMMAL RESEARCH PROGRAM
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Marine Mammal sensory systems have evolved to effectively use acoustic energy in the oceans. Our objectives are to develop a basic understanding of hearing and echolocation so that knowledge can then be applied to the solution of practical problems as they arise. The most basic hearing measurement is the audiogram which is a series of thresholds across frequencies. It basically describes the hearing of an organism. Audiograms are the most basic of the hearing measures and are essential for describing the audiometrics of a species of animals. Of the 85 species of dolphins and whales we now have audiograms on 17 species. Audiograms on additional cetacean, and other marine mammal, species may be obtained from stranded animals, from animals in captive display situations, and from catch and release scenarios. We intend to obtain as many valid audiograms as possible as we seek new opportunities in new situations. Most marine mammal audiograms are obtained on individuals and published individually. Population estimates obtain increased validitity with increased numbers of measurements. Other hearing measures such as directionality of hearing, and the mechanisms underlying that directionality, are also very important and little is known on most marine mammals. These measures will also be obtained whenever possible.
- Biological Oceanography