NOAAʻs Seirios camera sled images the ROV Deep Discoverer (D2) as it illuminates a ledge covered with a diverse assemblage of deep-sea corals and sponges. D2 displays its newly installed sample collection equipment – drawers, boxes, an advanced manipulator, and positionable illumination system – that have allowed us to do precision collections under direction of our science team leads. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2015 Hohonu Moana. Download larger version (jpg, 1.1 MB).
Dive 15 of the expedition was conducted today on a ridge located north of Maro Reef to survey a completely unexplored area for corals and sponges, providing more information on whether high-density communities can be found on ridge topography and that the orientation of the ridge is important. The dive started at 1,750 meters on a sloped surface consisting of manganese-crusted cobble, rubble, and boulders overlaying sediment, with several nearby chrygorgid coral colonies. As the ROV moved up the flank of the ridge, there was a modest density of corals, which mostly consisted of the species Metallogorgia melanotrichos. Once the ROV arrived at the crest of the ridge, the community changed to one dominated by the coral Pleurocorallium kishinouyei and a yellow species of unstalked crinoids. As the ROV moved east on the crest of the ridge, it passed over several large boulders which were covered with a high density of Iridogorgia bella coral and black corals. The ROV left the bottom at a depth of 1,555 meters after having covered a linear distance of 960 meters.