2026 Cook Islands ROV Exploration
Dive 06: B1 Seamount Bottom
The sixth dive of the 2026 Cook Islands ROV Exploration cruise took place on the lower flank of B1 Seamount. We explored the western ridge of the seamount during Dive 04 of the cruise, so this dive provided an opportunity to compare the seafloor texture, nodule characteristics, and biological communities present along a deeper segment of the seamount. Upon reaching the seafloor at the base of the seamount, at a depth of approximately 4,950 meters (3.1 miles), we encountered a dense field of polymetallic nodules. As we worked our way up the side of the seamount, the seafloor gradually changed, with nodules giving way to rounded and then angular features before transitioning into fully ferromanganese encrusted hard bottom. Marine life included sponges and sea cucumbers encountered on previous dives, plus a few new observations for this mission, including the deep-sea black coral, Abyssopathes and a faceless cusk eel. Data collected during this dive will help better characterize the geology and biology of seamounts in the region.
A large shark tooth, at least five centimeters (two inches) long, rests on a bed of potential polymetallic nodules. Polymetallic nodules form when iron and manganese minerals slowly build up, or accrete around a small object, like a shark tooth or grain of sand. They can take millions of years to grow to the size we see here. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 1.3 MB).
This black coral in the genus Abyssopathes was seen at a depth of 4,930 meters (3 miles) during Dive 06 of the 2026 Cook Islands ROV Exploration cruise. Black corals get their name from the dark color of their inner skeletons. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 714 KB).
A dense field of potential polymetallic nodules, each about the size of a tennis ball, seen during the beginning of Dive 06 of the 2026 Cook Islands ROV Exploration cruise, at the flank of “B1 Seamount.” Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 958 KB).
This polychaete worm was observed swimming in the water column just above the seafloor explored during the sixth dive of the 2026 Cook Islands ROV Exploration cruise. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 278 KB).
The scoop sampling tool on remotely operated vehicle Deep Discoverer is used to collect sediment and nodules from the seafloor during Dive 06 of the 2026 Cook Islands ROV Exploration cruise. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 1.1 MB).
A faceless cusk eel, seen during Dive 06 of the 2026 Cook Islands ROV Exploration, slowly makes its way through the water column. While this one didn’t turn towards the camera enough to give us a glimpse of its face (or lack thereof), these rare deepwater fish are known for their bulbous heads and hidden eyes and mouth. Video courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download HD version (mp4, 4.3 MB)