Dives 06 and 07: Debussy Seamount
September 13, 2017
Access Dive Summary and ROV Data

Dive 07: Dense, Diverse, and Hungry

On September 13, remotely operated vehicle (ROV) Deep Discoverer reached the seafloor at 2,200 meters (1.4 miles) depth on Debussy Seamount and was surrounded by a dense coral and sponge community as far as the camera could see. During the dive, scientists were able to make observations about the behaviors of various organisms that could only be achieved via live exploration with an ROV. Video courtesy of the NOAA Office of Ocean Exploration and Research, Deep-Sea Symphony: Exploring the Musicians Seamounts. Download (mp4, 32.9 MB)

Today we conducted two remotely operated vehicle (ROV) dives. The first, Dive 06, was aborted after a short time in the water due to a technical issue with ROV Deep Discoverer (D2). While our benthic team was disappointed, the ROVs are outfitted with sensors that collected valuable information about the water column during the descent and ascent that can be used to learn more about this largely unexplored biome. Once back on deck, the ROV team quickly debugged the issue, and we were back in the water a couple hours later.

Dive 07, though short, was exceptional. D2 landed on a low relief lava flow and rubble at a depth of 2,044 meters (6,706 feet). From the moment the vehicles reached the seafloor, a diverse coral community abounded. A novel find was a sea star predating upon a coral, as this was the first time a member of this genus of sea star has been observed eating a coral. Another unusual sighting was that of a deep-sea lizardfish at a depth of 2,031 meters (6,663 feet), the upper limit of its known depth range. As the vehicle traversed a large intact lava flow, the dense coral and sponge community continued. Alternating talus fields, intact lava flow units, and combinations of both were observed from 2,030 meters (6,663 feet) until end of the dive. The slope from beginning to end of the dive was almost negligible, and yet this dive possibly produced the most continuous high-density coral and sponge community of the expedition to date.