2021_programme: The impact of hurricanes on the underwater soundscape along the US Southeast Outer Continental Shelf



    • Day: Thursday 24th
        Location / Time: Room A at 17:40-18:00 (EEST, UTC+3)
    • Session: 01. Acoustic Monitoring of Ocean Environments and Processes: Biology, Ecology, Geophysics and Man-made activities
      Organiser(s): Jennifer Miksis-Olds
      Chairperson(s): Jennifer Miksis-Olds
    • Lecture: The impact of hurricanes on the underwater soundscape along the US Southeast Outer Continental Shelf
      Paper ID: 1520
      Author(s): Tripathy Aditi, Miksis-Olds Jennifer, Lyons Anthony
      Presenter: Tripathy Aditi
      Presentation type: Oral, pre-recorded
      Abstract: Hurricanes occur frequently in the North Atlantic, increasing the ambient sound due to wind-wave agitation. The relationship between ambient sound and hurricane intensity has been studied for many years, however, the impact of hurricanes on the detectability of marine mammals has not yet been assessed. The Atlantic Deepwater Ecosystem Observatory Network (ADEON) network is comprised of active and passive acoustic sensors mounted on bottom landers at seven locations in a combination of deep (>750 m) and shallow (500 m) areas on the US Mid- and South Atlantic Outer Continental Shelf. Multiple hurricane events were recorded in 2018 and 2019 during the ADEON data collection period. Hurricane Dorian (Category 5), Hurricane Florence (Category 4), and Hurricane Humberto (Category 3) impacted each of the lander locations, producing wind speeds of up to 50 knots. The durations of impact from the hurricanes were quantitatively defined using statistical properties of hourly wind speed time series near the lander locations. Passive acoustic data from the two-year period were analyzed at each location and changes in ambient soundscape components were assessed before, during, and after the defined period of impact from the hurricanes as determined by wind speed. One-minute power spectral densities, sound level percentiles, spectral probability densities, and spectrograms were computed and compared. The ambient sound level due to the hurricanes increased by up to 20 dB in the 0.1-7 kHz band with minimal effect in the 10-100 Hz band. Maximum impact from the hurricanes occurred at 0.2-3 kHz which may affect the detectability of marine mammals that vocalize at these frequencies such as minke, beaked, and sperm whales. [Study concept, oversight, and funding were provided by ONR Award N00014-16-1-2594 and BOEM under contract Number M16PC00003, in partnership with ONR and NOAA. Funding for ship time was provided under separate contracts by ONR, Code 32.]
    • Corresponding author: Ms Tripathy Aditi
      Affiliation: School of Marine Science and Ocean Engineering, University of New Hampshire
      Country: United States
      e-mail: