Passive Acoustic Monitoring in the Southeast United States
We use innovative passive acoustic technologies to record ocean sounds, including those produced by whales and dolphins, in the Southeast region.
All marine mammals produce sounds underwater to navigate, hunt, and communicate with each other, and scientists can listen to these sounds to learn more about them. The Passive Acoustic Ecology Program at the Southeast Fisheries Science Center uses underwater recording instruments to listen to, record, and detect all types of sounds in the ocean, including the sounds produced by whales and dolphins (cetaceans). These recordings and detections of vocalizing cetaceans help us to understand their distribution, abundance, habitat use, seasonal and longer term movement patterns, and calling behavior. All of this information contributes to management and conservation efforts.
We conduct large-scale short-term surveys using towed acoustic instruments during our ship-based offshore population assessments. We also conduct stationary long-term surveys using moored instruments that remain on the seafloor for long periods of time. These passive acoustic surveys are complementary to our visual surveys. They improve our ability to assess the population status of many marine mammal species inhabiting the Gulf of Mexico, the southeast U.S. waters of the North Atlantic, and the Caribbean.
Technologies We Use
Our scientists use a variety of passive acoustic technologies to record ocean sounds, including those produced by marine mammals.
During ship-based surveys, we may:
- Tow a hydrophone array (underwater microphones) to record and localize sounds from toothed whales and dolphins (odontocetes)
- Deploy drifting sonobuoys to record and localize sounds from baleen whales (mysticetes)
- Deploy animal-borne tags to understand call and dive behavior of marine mammals
For longer term monitoring of ocean and marine mammal sounds, we use moored autonomous acoustic recorders. They provide insights into marine mammal seasonal occurrence and distribution.
The Southeast Center conducts a variety of research using passive acoustic methods, in combination with other research methods, to assess populations and improve our understanding of cetaceans in the Gulf of Mexico and U.S. waters of the North Atlantic.
Vessel-based surveys incorporate passive acoustic monitoring to add complementary information on whales and dolphins for a broader understanding of their ecology. Some examples of this include:
- Atlantic and Gulf of Mexico Marine Assessment Program for Protected Species projects, which assess whale and dolphin distribution and abundance
- The Rice’s whale trophic ecology project, which helps us understand diet and feeding behavior
Other studies use autonomous moored acoustic recorders to improve our understanding of marine mammals. Some examples include:
- Monitoring changes in Gulf of Mexico marine mammal populations and soundscapes following the Deepwater Horizon oil spill (LISTEN GoMex project)
- Mapping the distribution of endangered species, like Rice's whales and North Atlantic right whales
- Characterizing the ocean soundscape and potential impacts of human-made noise on marine mammals
The Passive Acoustic Ecology Program is part of the Marine Mammal and Turtle Division of the Southeast Fisheries Science Center.
- Melissa Soldevilla, Ph.D. - Passive Acoustic Ecology Program lead
- Ashley Cook - Doctoral student at University of Miami, Rice’s whale studies
- Amanda Debich - Lead acoustic technician for Rice’s whale studies
- Heloise Frouin-Mouy, Ph.D. - Assistant scientist for LISTEN GoMex project, odontocete density estimation
- Lynne Hodge, Ph.D. - Acoustic technician for LISTEN GoMex project, shipping noise and marine mammal characterization
- Ludovic Tenorio, Ph.D. - Postdoctoral associate, Rice’s whale studies
Passive acoustic monitoring requires specialized equipment and produces a lot of data. These data require computer intensive analyses to discover all the important information about marine mammals and their acoustic habitats contained in the underwater sound recordings. The Southeast Center collaborates with many institutions within and outside NOAA to help us achieve these goals.
The agencies we work with include:
- Scripps Whale Acoustics Lab
- Scripps Machine Listening Lab
- Universidad Veracruzana - Serrano Lab
- Universidad Nacional Autónoma de Mexico - Gracia Lab
- NOAA Atlantic Oceanographic and Meteorological Laboratory
- NOAA National Centers for Environmental Information
- NOAA Northeast Fisheries Science Center