SanctSound: Listening to the (Not So) Silent World

Scientific voyages into the world of sound in the National Marine Sanctuary System

February 2021

By Sarah Marquis

Ever traveled to a new city and noticed how different it sounded from your hometown? Sound is one of many ways that marine animals experience their environments, and one of many ways that we can study the underwater world.

humpback whale
A humpback whale in the waters of Hawaiian Islands Humpback Whale National Marine Sanctuary. Photo: Ed Lyman, HIHWNMS/NOAA Permit 14682.

Long-Term Monitoring

SanctSound is a four-year project, managed by NOAA and the U.S. Navy, to better understand underwater sound within national marine sanctuaries. Since the fall of 2018, and through the spring of 2022, the agencies are working 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.

Standardized measurements across the system assess sounds produced by marine animals, physical processes like wind and waves, and human activities. Collectively, this information helps NOAA and the Navy measure sound levels and baseline acoustic conditions in sanctuaries.

A primary goal of the SanctSound project is to add information gained by listening to the other types of observations made in the National Marine Sanctuary System, such as 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.

“By integrating what we hear in this project with what scientists have learned about the animals and human activities in sanctuaries using other methods of study, we are better able to answer questions of interest to those invested in the future of these special places,” says Leila Hatch, marine ecologist with Stellwagen Bank National Marine Sanctuary and co-lead of the SanctSound project.

SanctSound is a continuation of ongoing Navy and NOAA monitoring and research, including efforts by NOAA's Office of National Marine Sanctuaries.

Building Common Knowledge

snapper by reef
The thumps and moans of groupers, pops of damselfishes, and classic grunting sounds of haemulid fish, such as blue striped grunts, can be heard by sound recording devices in Florida Keys National Marine Sanctuary. Photo: Daryl Duda
Atlantic Cod by shipwreck
Atlantic cod, such as the ones under this shipwreck in Stellwagen Bank National Marine Sanctuary produce grunting sounds associated with courtship behavior. These sounds can be recorded and help scientists to learn more about their mating behaviors. Photo: Matthew Lawrence

SanctSound research came to fruition due to a settlement agreement regarding the Navy's use of low frequency active sonar and impacts to marine mammals. The agreement supports topics linked to the implementation of NOAA's Ocean Noise Strategy. Co-led by NOAA and the Navy, SanctSound’s partners, from over twenty institutions around the country, are lending their expertise to analyzing, managing, and providing web access to the project’s new information. By providing updates to the many ocean interests represented on sanctuary advisory councils and research advisory boards as well as the environmental advocacy groups engaged in the settlement, the project is seeking to become a shared resource for people interested in learning about and protecting marine sanctuaries.

Sound Technology

researchers deploy a fixed acoustic recording device attached to a float
Sanctuary researchers deploy a fixed acoustic recording device attached to a float from a national marine sanctuary research vessel. Photo: NOAA
Slocum gliders are a type of autonomous underwater vehicle that can carry instruments to record sound along pre-programmed paths within national marine sanctuaries. Photo: Mark Baumgartner

Underwater listening technologies can vary, and the data derived from those recordings need to use the same baseline. As managers of a national system of marine protected areas, NOAA’s Office of National Marine Sanctuaries seeks standardized methods. This helps scientists to characterize sound conditions accurately and compare them over time. These comparisons are made using a network approach, in single locations over the project’s duration, across different locations within a single sanctuary, and across locations in different sanctuaries.

Although focused on collecting sounds at specific locations, the project also uses a type of autonomous underwater vehicle, called a glider, to record sounds while traveling to programmed waypoints in and around Stellwagen Bank and Gray’s Reef National Marine Sanctuaries and in the Papahānaumokuākea Marine National Monument. To better understand what we are hearing, recorders are often paired with receivers that can detect the nearby movement of tagged animals, are equipped with temperature sensors, and are often placed in locations where diver surveys are ongoing or other oceanographic monitoring is taking place.

Interactive Portal Coming Soon

Imagine all of the underwater sounds that you haven’t heard before! Using listening devices, sound information is being gathered, analyzed, and visualized from 30 locations. Monitoring is taking place on the East Coast in Stellwagen Bank, Gray's Reef, and Florida Keys national marine sanctuaries; on the West Coast in Olympic Coast, Monterey Bay, and Channel Islands national marine sanctuaries; and in the Pacific Islands Region in Hawaiian Islands Humpback Whale National Marine Sanctuary and Papahānaumokuākea Marine National Monument.

Listen to Some of the Sounds in Your National Marine Sanctuaries!

Listen to snapping shrimp in Channel Islands National Marine Sanctuary

Listen to dolphins in Channel Islands National Marine Sanctuary

Listen to humpback whale song in Hawaiian Islands Humpback Whale National Marine Sanctuary.

Through an interactive web portal launching in 2022, NOAA will provide a repository of publicly available information describing the soundscapes of these special places. There, anyone will be able to experience the underwater world of sound in our National Marine Sanctuary System.

Stay tuned for upcoming stories featuring some of the exciting SanctSound projects from across the nation!

Sarah Marquis is the West Coast/Pacific Islands media coordinator for NOAA’s Office of National Marine Sanctuaries.