Deep Sea Biodiversity of the Marshall Islands

While exploring the deep sea around the Republic of the Marshall Islands, our team on board E/V Nautilus was continuously amazed at the stunning biodiversity we encountered with our ROVs. Check out a grenadier fish (aka rattail) showing off its long dorsal fin and even longer tail, a crinoid next to a Brisingid sea star, and tons of sponges and corals dotting the seafloor. In this highlight video, you’ll also spot a deep-sea long-spine sea urchin, bryozoan invertebrates, and other less-easily identifiable creatures. From yellow Bolosoma sponges to white Corallium corals, these scenes remind us that even thousands of meters beneath the surface, complex ecosystems exist- and thrive -in the deep. 

The Republic of the Marshall Islands is an atoll-based country of over 1,200 islands surrounded by 2.13 million square kilometers of ocean, the vast majority of which has never been mapped or surveyed. Despite data gaps, it’s known that the deep sea of Aolepān Aorōkin Ṃajeḷ hosts rich and diverse marine resources, including these amazing animals, over 300 unexplored seamounts, extensive deep-sea ridges, and escarpments. This expedition was developed in collaboration and consultation with the Marshall Islands Marine Resources Authority and other local stakeholders and funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute.