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Multi-species Cetacean Satellite Tagging to Examine Movements in Relation to the 2008 Rim-of-the-Pacific (RIMPAC) Naval Exercise

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The Rim-of-the-Pacific RIMPAC naval exercise is a biennial multi-week multinational naval exercise that has been undertaken around the main Hawaiian Islands since 1968. Immediately prior to the 2004 RIMPAC exercise a group of 150-200 melon-headed whales, Peponocephala electra, a species that is typically found in deep waters in Hawaii, entered Hanalei Bay on the north shore of the island of Kauai, and remained in the bay for more than 24 hours Southall et al. 2006. While the exact cause of the event remains unknown, a review of available evidence concluded that active sonar transmissions by naval vessels prior to and during the period when the whales were inside the bay were a likely, if not plausible, contributing factor Southall et al. 2006. Considerable uncertainty remains regarding the causes of this event in part because no information is available on where the group of melon-headed whales was prior to the initiation of sonar use. This example illustrates the difficulty in understanding, assessing, andor predicting the potential reactions of cetaceans to naval sonar use. Such assessment is problematic for a variety of reasons, including limited observations of cetaceans before and during active sonar operations inter-specific variability in reactions beaked whales appear to be more susceptible to impacts than other cetaceans, see Cox et al. 2006 for a review likely variable reactions depending on type and number of sound sources and the proximity of individual cetaceans to the sound sources and potential intra-specific variability in reactions.

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  • Biological Oceanography
  • Military Operations, Strategy and Tactics
  • Active and Passive Radar Detection and Equipment

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