2026 American Samoa ROV + Mapping Exploration

This sea star (Atheraster arandae) was seen eating a bamboo coral (Jasonisis sp.) while diving on Rose Atoll during the 2017 Okeanos Explorer expedition in American Samoa. Image courtesy of NOAA Ocean Exploration, 2017 American Samoa. Download largest version (jpg, 469 KB).

Most of the 13,581-square-mile National Marine Sanctuary of American Samoa lies far below the sunlit coral reefs visible from shore. Its protected waters include deep seamounts, abyssal plains, deep-sea coral and sponge communities, and other habitats that remain largely unexplored.

As NOAA Ship Okeanos Explorer enters the waters of National Marine Sanctuary of American Samoa as part of a 29-day mission to explore deep waters in and around American Samoa, scientists and sanctuary managers are preparing for remotely operated vehicle (ROV) dives within the sanctuary. The dives, along with accompanying seafloor mapping, will provide a closer look at some of the least-understood habitats within these protected waters, including areas near Rose Atoll Marine National Monument.

Located in the cradle of Polynesia’s oldest culture, National Marine Sanctuary of American Samoa protects extensive coral reefs, including some of the oldest and largest Porites coral heads in the world, along with deepwater reefs, hydrothermal vent communities, and rare marine archaeological resources.

Map of the Samoan Archipelago highlighting the extent of the exclusive economic zone and the six units within National Marine Sanctuary of American Samoa. More full-resolution maps are available on the sanctuary’s location and maps page. Map courtesy of National Marine Sanctuary of American Samoa. Download largest version (jpg, 92 KB).

National Marine Sanctuary of American Samoa protects natural and cultural resources through research, education, partnerships, permitting, and regulation. Within sanctuary boundaries, regulations generally prohibit activities such as disturbing or altering the seabed, discharging certain materials, and damaging historical or cultural resources. Information collected during this expedition will help sanctuary managers better understand the deep-sea habitats and resources within these waters that are part of America’s National Marine Sanctuary System.

One planned dive will provide the first detailed video observations of abyssal plain habitat within the sanctuary. Found thousands of meters below the ocean surface, abyssal plains may appear featureless, but they can support specialized communities adapted to cold temperatures, extreme pressure, darkness, and limited food. Covering 70% of the seafloor, abyssal plains are the largest habitat on Earth. Documenting them within the sanctuary will establish baseline information about the animal inhabitants and the environmental conditions that shape deep-sea ecosystems.

Remotely operated vehicle Deep Discoverer imaging the seafloor off American Samoa during an expedition in 2017. Image courtesy of NOAA Ocean Exploration, 2017 American Samoa. Download largest version (jpg, 265 KB).

Another dive will explore an unnamed deep seamount to the east of Rose Atoll. The base of the seamount lies at approximately 5,500 meters (3.4 miles) depth and the top is about 3,000 meters (1.9 miles) from the surface. The site was near the operating depth limit of the ROV used during a previous expedition. Because ROV Deep Discoverer is designed to work at greater depths, scientists will now have an opportunity to examine the seamount more closely and investigate whether habitat-forming corals and other deep-sea organisms occur there.

To support education and outreach efforts about deep-sea exploration, National Marine Sanctuary of American Samoa co-hosted a professional development workshop with NOAA Ocean Exploration on August 19-20 at the Tauese P.F. Sunia Ocean Center. Engaging the American Samoa Department of Education, the workshop included lesson planning for 35 teachers to incorporate into classrooms across American Samoa.

This work reflects an ongoing partnership among National Marine Sanctuary of American Samoa, NOAA Ocean Exploration, NOAA Marine and Aviation Operations, NOAA Ocean Exploration Cooperative Institute, U.S. Geological Survey, and scientists participating from shore through telepresence technology. NOAA Ocean Exploration provides the mapping systems, ROVs, and technical expertise needed to explore areas that sanctuary teams could not study independently.

For sanctuary managers, the partnership’s value extends well beyond the expedition. Publicly available data will help characterize deep-sea habitats, understand their importance, evaluate emerging issues, support future research and long-term monitoring, and inform management decisions.

The expedition also offers opportunities to deepen public understanding of the waters surrounding American Samoa. Live video streams and ship-to-shore interactions allow local communities, students, scientists, and viewers around the world to follow the exploration as it happens.

By Rachel Plunkett, NOAA’s Office of National Marine Sanctuaries