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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 04: East Samoa Basin Abyssal Nodule Field

August 31, 2026

Location: Lat: -14.92325896°; Long: -166.55247106°    
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Dive 04 of the 2026 American Samoa ROV + Mapping Exploration expedition took place on an abyssal plain in the Samoa Basin, approximately 100 miles east of Rose Atoll. The dive started at a depth of approximately 5,140 meters (3.2 miles) on a medium-density polymetallic nodule field. Nodule density increased and the shape of the nodules became more ellipsoid over the course of the dive, as we moved up the mound. Numerous fossilized shark teeth, some with polymetallic coatings, were noted during the transect. Organisms observed during the dive included a number of glass sponges of different shapes and sizes, sea stars, sea cucumbers, a munnopsid isopod, a ctenophore, and a halosaur. After climbing eastward up the slight rise in the abyssal mound, the dive ended at a depth of approximately 5,125 meters (3.18 miles).

A translucent white glass sponge sits on a sandy ocean floor surrounded by dark nodules.

The most frequently observed organisms during Dive 04 of the 2026 American Samoa ROV + Mapping Exploration expedition were glass sponges of various shapes and sizes. These included stalked sponges that may have been Farreidae species, Euplectellidae vase-shaped species, and flattened sponges that were the shape and size of a dinner plate. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 525 KB).

A robotic arm places a white square grid over dark nodules on a sandy deep-sea floor.

During the fourth dive of the 2026 American Samoa ROV + Mapping Exploration expedition, the team placed a grid, 25 x 25 centimeters (10 x 10 inches), on the seafloor to measure nodule abundance. The team then collected nodules from this area using a scoop. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 807 KB).

Three operators in a dark control room monitor deep-sea video feeds on multiple glowing screens.

Remotely operated vehicle (ROV) pilots in the control room of NOAA Ship Okeanos Explorer collect polymetallic nodules using the scoop sampler on ROV Deep Discoverer during Dive 04 the 2026 American Samoa ROV + Mapping Exploration expedition. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 833 KB).

A textured xenophyophore and a brittle star sit among dark round nodules on a sandy deep-sea floor.

The lighter-colored round object near the center of this image is a xenophyophore, seen during Dive 04 of the 2026 American Samoa ROV + Mapping Exploration expedition. Molecular analysis has confirmed that xenophyophores are single-celled organisms belonging to the phylum Foraminifera. They are only found in the deep ocean, building elaborate “houses” using material from the seafloor. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 599 KB).

A pale anemone with extended tentacles sits on a dark rock among round nodules on a sandy seabed.

An anemone takes advantage of the hard surface provided by a polymetallic nodule. Seen during Dive 04 of the 2026 American Samoa ROV + Mapping Exploration expedition. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 553 KB).