Deep-sea coral provides a habitat for many other animals. In this image, a pycnogonid or sea spider may be feeding on an anemone while both of them are living on a Paramuricea coral. Image courtesy of the NOAA Office of Ocean Exploration and Research, Northeast U.S. Canyons Expedition 2013. Download larger version (jpg, 1.3 MB).
A chimaera swims lazily a couple meters above the seafloor in Lydonia Canyon. Video courtesy of the NOAA Office of Ocean Exploration and Research, Northeast U.S. Canyons Expedition 2013. Download video (mp4, 3.5 MB).
Today we had a deep dive along the southwestern wall of Lydonia Canyon. The remotely operated vehicle (ROV) was on bottom at 1,236 meters, ready to start exploring at 1328UTC. The dive track started at the base of a wall and transited up and around a promontory. The primary geological attributes seen included rock walls with erosional features, clear ledges of harder rock, light in color, possibly consisting of chalk or limestone. The dive was characterized by scattered patches of corals living on the rock face, including Swiftia, Paramuricea, bamboo, and Anthomastus. Swiftia was extremely common throughout the dive. In contrast, a high abundance of fauna were observed living on the underside of ledges, including bivalves, Solenosmilia, cf. primnoid, cup corals, squat lobsters, and sponges. Scale worms, ophiuroids, a few solitary hydroids, and sipunculids were observed on sediment laden rock slopes. Two individuals of Neolithodes were observed clinging to the rock face, one of which had barnacles attached to its shell. Two grey/purple shrimps, cf. Glyphocrangonidae, were imaged on sedimented rock. These were observed on a previous dive this leg. At least 15 coral species were observed (Swiftia, Paramuricea, Paragorgia, Anthomastus, bamboo-unknown, white stoloniferous coral, sea pen, Bathypathes-related, Keratoisis, Solenosmilia, Parantipathes, Clavularia, cf. Desmophyllum, cf. Javania, Primnoa, Paragorgia). Fishes included black dogfish, chimaera, ophididae, halosaur, synaphobranchid eel, Chaudiolus, long-fin hake, grenadier, flounder, Notocentridae (spiny eel, first time observed this expedition), and cf. Cyclothone.
For the first time this cruise, we observed a purple deep-sea nudibranch, Tritonia sp., known to consume stoloniferous corals. In addition, an egg mass, likely from a fish, was found on Bathypathes-related black coral. We observed two potential predation events, a sea star sitting on an Anthomastus octocoral and a pycnogonid with its proboscis touching an anemone attached to a Paramuricea. At the end of the dive, we saw a large Paragorgia, covered with ophiuroid associates. The ROV left bottom at 1953 UTC at 1,136 meters.