The Impact of Hurricanes on the Acoustic Detection of Cetaceans
Ocean Engineering
Passive acoustic monitoring (PAM) is valuable for understanding the presence, behavior, distribution, and population density of marine mammals. While long-term variability of ambient sound is typically evaluated, the impact of short-term variability due to episodic events has not been assessed until now. Hurricanes Dorian (Category 5; 2019), Florence (Category 4; 2018), and Humberto (Category 3; 2019) impacted the soundscape as observed from the passive acoustic data at the Atlantic Deepwater Ecosystem Observatory Network (ADEON) locations in the US Mid- and South Atlantic Outer Continental Shelf. Hurricanes are increasingly prevalent in the North Atlantic and increase the ambient sound level at frequencies > 100 Hz, which may impact the detectability of cetaceans vocalizing at those frequencies. The probability of detection (Pd) of fin whales (low-frequency), minke whales (mid-frequency), and pilot whales (mid- to high frequency) was estimated at each ADEON location. Pd changed considerably during hurricane presence with site-specific impacts for each of the cetaceans, which may affect estimates of their population density from passive acoustic recordings. The findings from this study provide a baseline for impacts of episodic variability of varying intensities on signal detection, and can be translated to additional episodic events and sound sources of interest, to further enhance PAM efforts.
Aditi’s advisors are Dr. Jennifer Miksis-Olds and Dr. Anthony Lyons, and her committee members are Dr. Thomas Lippmann, and Dr. Kim Lowell.
Aditi Tripathy earned her Bachelor of Science in Marine Biology with a minor in Acoustics (Ocean Engineering) from the University of Rhode Island, where she worked on characterizing the soundscape near the Block Island Wind Farm, which is the first offshore wind farm in the US. She was a Visiting Research Scholar at the National Oceanography Centre Southampton (NOCS) in the UK. During her time as a Master’s student in Ocean Engineering at UNH, Aditi focused on understanding the impacts of episodic oceanographic variability on ocean acoustics and marine mammals. She stands contentedly at the crossroads of Marine Biology and Ocean Engineering, and looks forward to continue listening underwater as Acoustical Engineer at Tetra Tech.