INFLUENCE OF STORMS ON MARINE MAMMAL VOCALIZATION

• Main Author: Anthony, Brandon
• Other Authors: Joseph, John E., Margolina, Tetyana, Oceanography (OC)
• Format: Thesis
• Language: unknown
• Published: Monterey, CA; Naval Postgraduate School 2021
• Subjects: passive acoustic; marine mammals; storms; baleen whale; Fin whale
• Online Access: https://hdl.handle.net/10945/67654

Passive acoustic data collected from four sites in the Monterey Bay National Marine Sanctuary were analyzed to compare the vocalizations of three baleen whale species to the incidence of four storm events. Periods of rainfall were identified using a combination of radar reflectivity data, utilized by weather services around the world, and analysis of the 16 kHz octave level. By utilizing trained human analysis, changes in vocalization patterns were identified for blue whales and humpback whales. Fin whale calls were calculated by analyzing power differences between 12, 20, and 30 Hz frequency bands. Blue whales had the most marked response to the storm events, with rainfall showing the biggest impact. Fin whales also changed their behavior, but only in response to larger amount of rainfall. Humpback whales only responded to the strongest storm event. Although these findings indicate that whales alter their behavior when confronted by weather events, they do not indicate that whales depart an area. These changes in patterns alter the overall soundscape, and this understanding can increase the ability to manage resources for conservation and naval operations. Approved for public release. Distribution is unlimited. Lieutenant Commander, United States Navy