| "Some people talk to animals. Not many listen though. That's the problem."
NOAA-Navy Soundscape Monitoring in National Marine Sanctuaries
After two years of successful acoustic monitoring in four National Marine Sanctuaries, we have partnered with NOAA and Navy colleagues across the U.S. to coordinate a national-scale project to monitor soundscapes in seven National Marine Sanctuaries and one National Monument. In late 2018, long-term acoustic recorders equipped with calibrated hydrophones (SoundTraps, developed by Ocean Instruments NZ) were deployed in Stellwagen Bank, Gray's Reef, Florida Keys, Olympic Coast, Monterey Bay, Channel Islands, and Hawaiian Islands Humpback Whale National Marine Sanctuaries and Papahanaumokuakea National Marine Monument. The project aims at understanding the acoustic environment of National Marine Sanctuaries from standardized measurements of sounds produced by marine animals (invertebrates, fishes, and mammals), physical processes (e.g., wind, waves, and currents), and human activities (e.g., vessel operation and exploration activities). Sounds of animals and human activities will enhance our understanding of species presence, behaviors, and habitat use. This new initiative will result in continuous acoustic monitoring at these sites into the foreseeable future, providing important information on current and future soundscapes across the U.S. Additional information about the project can be found here.
The Passive Acoustic group at the Northeast Fisheries Science Center oversees the continuous acoustic monitoring of the East Coast region, maintains acoustic recorders at three sites in Stellwagen Bank, three sites in Gray's Reef, and four sites in the Florida Keys National Marine Sanctuary, and coordinates with partners to gather ancillary data to compare with sounds recorded, such as visual and habitat survey data, telemetry detections from tagged fish, data collected with gliders, and vessel GPS data from satellites. While we seek to record and analyze all sound sources, each chosen location is enhanced by its importance for certain species and levels of human use. Within Stellwagen Bank, our three sites cover known spawning grounds of Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus), regions of high marine mammal use, and areas of varying degrees of vessel presence. The sites in Gray's Reef encompass areas inside and outside of a designated closed research area and sites with historical data indicating their importance for species within the grouper-snapper complex, black sea bass (Centropristis stiata), numerous other fish species that are believed to produce sounds, and cetaceans. The sites in the Florida Keys target regions with varying levels of human use, deeper locations that historically were thought to be important spawning sites for species in the grouper-snapper complex, and sites with ongoing fish and turtle tagging efforts.
While recording sounds is relatively easy, our goal of making sense of them is more difficult. Similar to other regions, recordings of sounds within the East Coast region will be used to characterize the holistic soundscape and further our understanding of soniferous species presence/absence/habitat use, daily/lunar/seasonal patterns in sound production, and anthropogenic sound inputs. Through comparisons with other data sources we will be able to assess how the components of soundscapes relate to specific behaviors of fishes, marine mammals, and humans. Our pursuit of documenting soundscapes and decoding their components is ongoing and encouraging. To date, we have begun to identify patterns in fish sounds and choruses that are related to spawning activity during certain times of year, how sounds levels change as a function in time, and how sounds from human activity differ at each site. As the project continues, the ever-changing soundscapes of National Marine Sanctuaries will be documented and deciphered to provide meaningful information about their residents, visitors, and acoustic properties to Sanctuary managers, collaborators, and various public stakeholders.