Baleen Whale Calls and Seasonal Ocean Ambient Noise

• Main Authors: Hildebrand, John A, McDonald, Mark A
• Other Authors: CALIFORNIA UNIV REGENTS LA JOLLA CA SCRIPPS INST OF OCEANOGRAPHY
• Format: Text
• Language: English
• Published: 2000
• Subjects: Biological Oceanography; Physical and Dynamic Oceanography; Acoustics; *AMBIENT NOISE; *SEASONAL VARIATIONS; *WHALES; ACOUSTIC RECORDING SYSTEMS; ACOUSTIC TOMOGRAPHY; HYDROPHONES; NORTH PACIFIC OCEAN; OCEANS; *BALEEN WHALE CALLS; *SEASONAL OCEAN AMBIENT NOISE; BLUE WHALES; FIN WHALES; HUMPBACK WHALES; Pacific; baleen whale; Blue whale; Fin whale; Humpback Whale
• Online Access: http://www.dtic.mil/docs/citations/ADA609551; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA609551

The goal of this study is to quantify the ambient noise contributions and whale population densities for blue, fin, and humpback whale in the North Pacific. This study will contribute to understanding the seasonal distribution of two acoustically different fin whale populations, two acoustically different blue whale populations, and of humpback whales. An ocean ambient noise data set has been collected for more than five years in conjunction with the ATOC ocean acoustic tomography project. These data are spectra to 500 Hz in 1 Hz bands averaged over 170 seconds recorded at five minute intervals at each of 15 deep ocean hydrophones from 1994 to 2000. These data are unique because of the widely separated hydrophone locations, the unclassified status of the data, and the long duration of the data set. Our objective is to analyze these five years of acoustic recordings to understand the whale contribution to ambient noise. While whales have long been known to be a contributor to ocean ambient noise, these data reveal the whale contribution to be far greater than generally understood The study will contribute to the understanding of how often whale calls are masked by man-made noise such as shipping and to the performance evaluation of Navy sonar systems such as LFA. Information on whale distribution is relevant to the Navy whale distribution databases such as LMRIS (C. Burris, SPAWAR) which is designed to provide information on marine mammal distribution and seasonality to the fleet. Prepared in collaboration with the Applied Physics Laboratory, University of Washington, Seattle.