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SanctSound: Studying the Underwater World of Sound

Whale fin appearing in foreground with ship in background
Courtesy of John Calambokidis/Cascadia Research

Our world’s ocean is filled with a symphony of sounds, each with its own purpose. To better understand underwater sound within National Marine Sanctuaries, NOAA and the U.S. Navy co-led the Sanctuary Soundscape Monitoring Project, SanctSound. 

From fall 2018 through spring 2022, the agencies worked with numerous scientific partners to study sound within seven National Marine Sanctuaries and one Marine National Monument, in waters off Hawaii and the East and West coasts of the continental United States.

SanctSound assesses sounds produced by marine animals, physical processes like wind and waves, and human activities. This information helps NOAA and the Navy measure sound levels and baseline acoustic conditions in sanctuaries. The new data gathered by SanctSound will join information gained by listening to the other types of observations made in the National Marine Sanctuary System, including satellites, scuba and visual surveys, and research expeditions. Underwater sound recordings, when made over long periods of time in standardized ways, can greatly add to the suite of measurement systems that characterize the diversity and health of marine environments.

There are many sources of sound in sanctuaries. This graphic highlights the sound sources that were focused on in the SanctSound project, including physical (purple bar), animal (green), and human-made (orange). The length of the bars indicates the range of frequencies (or pitches) that are typical of that sound source. For comparison, the yellow bar at the base of the graph shows the hearing range of humans in air and is also the range of frequencies that were recorded by SanctSound hydrophones. Courtesy of Aline Design for NOAA

Making Data Accessible

SanctSound has collected close to 300 terabytes of data. For context, approximately 500 hours of film can fit in one terabyte. A primary goal of SanctSound is to allow people to easily explore and access much of that data and to showcase the types of information that sound can provide to help us understand and protect our ocean and its inhabitants.

NCEI is the repository for the data collected throughout SanctSound. The project’s data can be discovered, filtered, and accessed through the NCEI Passive Acoustic Data Archive web-based map viewer and immediately downloaded from Google Cloud Platform thanks to the NOAA Big Data Program

The NCEI Passive Acoustic Data Archive stewards and provides access to SanctSound and other acoustic monitoring project data through its dedicated web-based map viewer. Acoustic recording locations are depicted as dots on the map, color-coded by monitoring project. SanctSound specific data are the orange dots. Courtesy of NOAA NCEI.

Another key component of SanctSound is the new interactive data portal. The portal introduces the project to users from a wide variety of backgrounds through guided questions like why and how did we listen, where and when did we listen, what did we measure, what did we hear, what did we learn, and who we are. Users can also interactively explore the processed data, which includes detections of specific sounds, such as humpback whale song and red grouper fish calls, and sound level metrics that characterize the overall soundscape. The data portal is hosted by the U.S. Integrated Ocean Observing System (IOOS).

The data archive and web portal provide access to a variety of interesting underwater sounds including:

Snapping shrimp use their larger claw to create and pop bubbles, resulting in a loud snapping sound from which they derive their namesake. This snapping shrimp was recorded in the Florida Keys National Marine Sanctuary. Image courtesy of Wikimedia Commons.
A vessel and dolphin whistles overlap in this recording of the listening station located in the shipping lanes that transit the northern end of Olympic Coast National Marine Sanctuary. Photo courtesy of NOAA.
A cacophony of humpback whale songs and snapping shrimp snaps can be heard in this recording from west Maui within the Hawaiian Islands Humpback Whale National Marine Sanctuary. Photo courtesy of NOAA.