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The image depicts a remotely operated underwater vehicle (ROV) illuminating a section of the ocean floor. The ROV’s bright lights cast a blue glow on the textured seabed, highlighting its rough surface. The surrounding water is a deep blue, fading into darker shades as it extends away from the light source, creating a sense of depth.

2026 American Samoa ROV + Mapping Exploration

Dive 03: North Tutuila Flank

August 29, 2026

Location: Lat: -14.189761; Long: -170.713046      
Dive Depth Range: 1,290-1,390 meters (4,232-4,560 feet)
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Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition took place on the northern flank of Tutuila Island, on a mound slightly east of the mound explored during Dive 02. The dive started at a depth of approximately 1,400 meters (4,560 feet), climbing up a rise on the flank of the island. Throughout the dive, the makeup of the seafloor changed several times, transitioning back and forth from heavily sedimented areas to lava boulders and outcrops. In the sedimented areas, we observed a range of animals, including fish, hermit crabs, shrimp, anemones, and other invertebrates. In areas with hard volcanic rock surfaces, the diversity and abundance of marine life was greater, ranging from a variety of corals and sponges to anemones, crinoids, and sea stars.

During Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition, this sea cucumber put on quite a show. Sea cucumbers, also known as holothurians, belong to an unusual class within the phylum Echinodermata, a name literally translating to “spiny-skinned animals.” Although many sea cucumbers spend much of their lives slowly wandering across the seafloor to consume sediment-bound nutrients, certain species are capable of rising into the water column. They use powerful, rhythmic body flexes to swim upward until they reach neutral buoyancy and drift along until descending back to the seafloor for their next meal. Video courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download SD version (mp4, 15.3 MB) Download HD version (mp4, 41.5 MB)

A dark tripod fish rests on a light sandy seabed, supported by its long, thin fin rays.

During the third dive of the 2026 American Samoa ROV + Mapping Exploration expedition we saw several tripod fish standing on their fins on the seafloor. These fish face into the current and use their long appendages to sense food as it drifts by in the water column. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 492 KB).

A smiling researcher in a ship's laboratory weighs a sample basket using a handheld digital scale.

Data manager Anna Lienesch weighs a rock sample collected during Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition. Geological samples collected during expeditions on NOAA Ship Okeanos Explorer are archived with the Marine Geological Samples Laboratory at the University of Rhode Island. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 587 KB).

A pale sea cucumber covered in small shells and debris rests on a light, sandy ocean floor.

An interesting observation during Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition was this large sea cucumber that had attached small pieces of shell and forams to its body. Scientists aren’t sure why the sea cucumber “wears” such a costume. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 490 KB).

Two circular patterns of small holes mark a flat, sandy ocean floor.

Throughout Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition, heavily sedimented areas of the seafloor were observed to have a number of circular bioturbations, ranging in size from 10 centimeters to nearly a meter in width. Examination of these features with a scoop did not unearth any explanation for how they were formed. Some possible explanations suggested by the science team included buried echinoderms, amphipod burrows, feeding disturbance, or nesting patterns. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 458 KB).

A large, dark, textured boulder with small marine growths rests on a sandy seabed among other rocks.

Basalt boulders seen during Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition provided plenty of hard surfaces for organisms such as anemones, soft corals, and sponges to attach to. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 569 KB).

This crinoid, seen during Dive 03 of the 2026 American Samoa ROV + Mapping Exploration expedition, was perched on the top of a primnoid coral with its arms spread like a spiderweb to catch food particles drifting past in the water column. Getting up off the seafloor not only provides the crinoid with better access to food but also likely provides additional protection from potential predators. Video courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download SD version (mp4, 25.1 MB) Download SD version (mp4, 68.1 MB)

This beautiful cluster of Anthomastus octocorals was observed during the third dive of the 2026 American Samoa ROV + Mapping Exploration expedition. These corals have very large polyps. When these polyps retract, the body of the coral shrinks down significantly to just a small ball in the middle. But we restrained ourselves and resisted the urge to poke the coral to see what would happen. Video courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download SD version (mp4, 15.6 MB) Download HD version (mp4, 42.4 MB)