One organism's trash is another's treasure—these crinoids have taken up residence on a tall dead sponge stalk to give them better access to food in the water column. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2015 Hohonu Moana. Download larger version (jpg, 650 KB).
Today’s dive explored the crest of a ridge extending south of one of the plateaus of the Karin Ridge. ROV Deep Discoverer (D2) began the dive at a depth of 2,170 meters in an area with sponges, anemones, crinoids, and a dandelion siphonophore. As D2 transited up the slope, we documented several more sponges, anemones, and crinoids as well as a few octocorals and fish (cutthroat eel and rattails). Midway through the dive, we encountered a field of stalked sponges and concluded the dive on a topographic high with several octocorals, including representatives from every major deep-sea octocoral families. Other fauna observed during the dive included barnacles, hydroids, an aplacophora (shell-less snail), and polychaetes. During the dive, we collected one rock and two unusual bamboo corals.