Locating Potential Deep-sea Coral Habitat in the Gulf of Maine

The Gulf of Maine, bordered by Massachusetts, New Hampshire, Maine, and the Canadian provinces of New Brunswick and Nova Scotia, is a productive and dynamic marine environment. It is home to a diverse array of economically important fisheries, including Atlantic cod, herring, lobster, and scallops. It boasts unique underwater habitats, from kelp forests and eelgrass beds to deep-sea coral, all of which may provide shelter and breeding grounds for many marine organisms. The Gulf of Maine’s seafloor has a complex topography of deep basins, shallow banks, and steep slopes. However, there is extremely limited high-resolution mapping data available, especially in deeper waters. 

The Exclusive Economic Zone (EEZ), generally extending from the coast to 200 nautical miles offshore, is the maritime zone for which a coastal country has jurisdiction over natural resources. Over four million square miles, the US EEZ is larger than all 50 states combined, yet 48% remains unmapped and unexplored. Accurate ocean depths and topography are essential for resource management and responsibly developing and maintaining coastal infrastructure.

To improve understanding of the seafloor, the United States established the Strategy for Mapping, Exploring, and Characterizing the United States Exclusive Economic Zone (NOMEC). The Gulf of Maine is one of the highest mapping priorities due to its significant commercial fisheries supported by diverse habitats, including deep-sea corals, and the potential to support wind energy.

Two Saildrone Voyager uncrewed surface vehicles (USVs) surveyed 1,500 square nm in an area of the north-central Gulf that had never been mapped in high resolution. This expedition supports the National Oceanic and Atmospheric Administration (NOAA)’s deep-sea coral surveys, as well as other NOAA missions. In particular, good mapping data is necessary to guide the search for deep-sea coral, which serves as habitat for important fisheries. The mission primarily focused on the Jordan and Georges Basins, at depths up to 300 meters (900 feet). The data has revealed a complex and varied underwater landscape, reflecting its glacial history and dynamic oceanographic processes.

“The Saildrone Voyagers are filling in a substantial gap in seafloor data in the Gulf of Maine. NOAA and partners are very interested in better understanding habitats in the region that may support fish production. These high-resolution seafloor maps will inform future surveying and modeling efforts, as well as aid in the New England Fishery Management Council (NEFMC)’s fishery management decisions,” said Heather Coleman, a researcher with the NOAA Fisheries Office of Habitat Conservation’s Deep Sea Coral Research and Technology Program.

A Saildrone Voyager is a 10-meter (33-foot) USV designed specifically for near-shore ocean and lakebed mapping. It carries a payload of science sensors and mapping echo sounders, as well as navigation and communications equipment. The Saildrone Voyager is the only survey USV that can deliver long-duration International Hydrographic Organization (IHO)-compliant multibeam mapping surveys and ocean data collection at depths up to 300 m (984 ft). Saildrone USVs are primarily wind and solar-powered, but the Voyager also carries a high-efficiency electric motor for speed and maneuverability in light winds.

The multibeam and backscatter data collected in the Gulf of Maine will inform new species distribution models in the Gulf, which was previously not possible with the lack of high-resolution seafloor information. These new maps will also help update nautical charts and aid navigation, filling important gaps in bathymetric coverage.

“This is the first successful demonstration of Saildrone Voyager mapping capabilities, pushing the envelope of what is possible using autonomous systems for shallow to mid-depth EEZ mapping. Its state-of-the-art Norbit multibeam echo sounder combined with near-silent operations and classification from the American Bureau of Shipping, make Saildrone’s Voyager the USV of choice for near-shore mapping. These capabilities can be applied for any number of missions, from habitat exploration to safety of navigation to site characterization for offshore wind,” said Brian Connon, Saildrone’s VP of Ocean Mapping.

Saildrone has been operating autonomous data collection missions for ocean research, seafloor mapping, and maritime security since 2015. To date, Saildrone has built more than 140 USVs across the three Explorer, Voyager, and Surveyor classes. The Saildrone fleet has already spent more than 42,000 days at sea and sailed more than 1,300,000 nm from the High North to the Southern Ocean. Earlier this month, Saildrone began a mission to map 29,300 square nautical miles of the Cayman Islands’ EEZ.