Amazing Ocean Sighting: First Nautiloids Spotted from E/V Nautilus on Last Dive of Season

During a remotely operated vehicle (ROV) dive in the German Channel in Palau, the Ocean Exploration Trust (OET) witnessed four Palau nautilus individuals (Nautilus belauensis). These are the first sightings of nautiloids — the most primitive cephalopods — from E/V Nautilus after 1000+ ROV dives over the last 15 years of operations. This marine mollusk found in the Indo-Pacific is rarely photographed- let alone caught on video -and 2024’s expeditions represent the first of OET’s adventures within the nautilus’s expected distribution range. This expedition (NA169) was funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute.




"In addition to the obvious milestone of seeing a nautilus while onboard the eponymous Nautilus, it was also surreal to encounter an animal whose body plan and behaviors have barely changed since the age of the dinosaurs,” says Samantha Wishnak, Expedition Leader and Operations Coordinator at OET.

The Palau nautilus is a highly mobile marine scavenger and predator found on reef slopes between 95 to 504 meters deep. Not much is known about these cephalopods listed as Near Threatened by the IUCN Red List. There are 11 species of chambered nautilus recognized in the Family Nautilida, with the Palau nautilus identifiable by differences in shell coloration, pattern, and shape. The species displays behavior associated with Diel Vertical Migration as it migrates into shallower waters after dark and back down to the deep before sunlight.

OET Founder Dr. Robert Ballard named OET’s ship E/V Nautilus after the famous fictional submarine from the novel “20,000 Leagues Under the Sea.” Similar to the vertical movements of submarines, nautiluses are known for moving up and down in the water column. The name "nautilus" comes from the Greek word for sailor."

"Palau has been a focus for scientific research on the nautilus species for decades, revealing many aspects of their life history. But to actually see them in their natural habitat is difficult, and the technological marvels of the E/V Nautilus have allowed the eponymous vessel to finally meet this iconic marine organism 'face to face',” says Patrick Colin, science team member and Director of the Coral Reef Research Foundation.

The nautiloids were spotted during dive H2805- the last dive of the seven-month 2024 Nautilus season. The dive in the German Channel in the waters of Koror State provided a smorgasbord of biological, geological, and archaeological highlights. As the vehicles moved upslope from the base towards the mouth of the channel, the team documented the changing geomorphology and sand ripple features via video and high-resolution multibeam surveys. Multiple large sixgill sharks swam by the ROVs. In addition to these charismatic creatures, anthropogenic objects were also observed, including rusted metal debris, munitions, glass soda bottles, an anchor chain, and a large anchor, all thought to be from World War II.

"Being in the control van for our first sighting of this animal was pretty incredible. Everyone was so excited - you could feel the collective energy and childlike joy - finally seeing something everyone had been hoping to see. It takes a lot of teamwork to make moments like this possible, but for me personally, it felt amazing to be in control of the cameras on Hercules and Atalanta. It's something that will stay with me for a very long time,” says Jacob Ottaviani, video engineer and documentarian on this expedition, and Video Editor at OET.

This dive was led with science partners from the Scripps Institution of Oceanography in collaboration with the Coral Reef Research Foundation. One of the partners for the NA169 expedition is the Scripps Institution of Oceanography. Founded over 120 years ago, Scripps Institution of Oceanography is the oldest and largest institution dedicated to marine research, committed to exploring and understanding the oceans, atmosphere, and Earth’s ecosystems to address environmental challenges and support sustainable stewardship of marine resources. During this expedition, their team will deploy a fleet of robots from E/V Nautilus, including wave gliders, buoyancy gliders, autonomous surface vehicles, and vertical profilers.

"Whenever you see a rare animal in the ocean, there is always a sense of awe. The nautilus isn't a new species, but there is still a certain magic to seeing it move in real-time across the ocean floor and respond to the ROV. And it has no idea that hundreds of humans are staring at it!" says Alice Chou, onboard Science Communication Fellow.

Ocean Exploration Trust, a nonprofit founded by Dr. Robert Ballard, operates with a mission to explore the unknown parts of the ocean, seeking out new discoveries while pushing the boundaries of technological innovation, education, and outreach. OET promotes science, technology, engineering, art, and mathematics (STEAM) education worldwide using the excitement of exploration to inspire the next generation of scientists and engineers.

OET’s ten 2024 expeditions in Hawaiʻi, American Samoa, US Pacific Remote Islands, Palau, and Canada will contribute to the ocean being better understood by supporting international scientific and U.S. governmental priorities, particularly understanding ocean changes, sharing that knowledge with others, and contributing discoveries and data that will inform future conservation and management decisions.





Location: German Channel, Koror State, Palau