Sundry of Deep-Sea Sponges in the Marshall Islands

While exploring the waters of the Marshall Islands during the NA174 expedition, we were lucky enough to see a variety of deep-sea sponges on the seafloor. Using our slurp tools, we collected some subsections of these animals that are critical to creating deep-sea habitat for many different associates. This is apparent when you see the leafy Tretopleura sponge covered in crinoids and the small shrimp, living inside the enclosed vase of a Regadrella sponge. Coming in all shapes, sizes, and colors, sponges like the magnificent alien (Advhena magnifica) sponge and “fluffy” Caulophacus glass sponge remind us of the sculptural otherworldliness of the deep sea.

Some of the most massive sponges ROV Hercules encountered were located inside the National Marine Sanctuary of Bikar and Bokak (the first marine sanctuary in the Republic of the Marshall Islands, established in 2025). Learn all about sponge life cycles, anatomy, and ecology with this compilation video.  

The NA174 expedition to explore the deep sea of the Republic of the Marshall Islands is funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute.