A very large spectacular stalked sponge (Caulophacus sp.) encountered during the dive. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2015 Hohonu Moana. Download larger version (jpg, 655 KB).
Today’s dive was located on a sharp ridge that extended west from East Salmon Bank, and its objective was to survey for the presence of high densities of corals and sponges and examine the impact of ridge orientation on the presence of high-density communities. The dive started at 2,282 meters on a manganese-crusted, sloped surface covered with boulders and rubble with a moderate density of sponges and corals. As the ROV moved up the slope, the density of animals remained moderate and included sponges, corals, and asteroids. Further up the ridge, the ROV passed by a region of well-preserved pillow flows at 2,206 meters, which had a higher density of corals and sponges growing on them. The ROV left the bottom at a depth of 2,103 meters after a total bottom time of five hours and 50 minutes, having covered a linear distance of 730 meters.