At the beginning of the dive, squid (Illex sp.) were common. Image courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico 2018. Download larger version (jpg, 1.0 MB).
A hermit crab wandered on the seafloor, bumping into a slope dragonet (Centrodraco sp.) at approximately 310 meters (~1,015 feet) deep. Image courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico 2018. Download larger version (jpg, 1.2 MB).
This tiny sea star, less than five centimeters (less than two inches) across, could be a rare Remaster palmatus (family Korethrasteridae). If so, this could be one of the first live observations of this species in the Gulf of Mexico. Image courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico 2018. Download larger version (jpg, 1.0 MB).
Today’s dive surveyed a large, unexplored sinkhole off the Pourtales Terrace to a depth of ~490 meters (~1,610 feet). The bottom was covered with a lot of sediment and swarming with small fishes, shrimp, squid, and crabs. Several patches of Sargassum seaweed and various pieces of human-made debris were encountered, including balloons, cans, and fishing gear. On the northern side of the sinkhole, fish became less abundant and a rock outcrop was observed. Going upslope towards the rim of the sinkhole, larger rock outcrops with isolated corals and sponges were observed. Climbing the sinkhole wall, the substrate changed to limestone covered by a thin layer of sediment. Glass sponges were occasionally seen on the substrate, as well as tube worms, anemones, crinoids, urchins, and bryozoans.
Moving away from the sinkhole and towards the terrace, the terrain became flatter. Brittle star arms protruded from the numerous holes in the flat terrain. Demosponges (Phakellia sp.) became common, as did snowshoe urchins (family Echinothuriidae). Other invertebrates recorded included glass sponges, crabs, squat lobsters, anemones, lace corals, sea stars, squid, hermit crabs, byozoans, and hydroids. Fish included short-bearded codling, blackbelly rosefish, armored searobin, roughy, rattails, hake, herring smelt, cardinalfish, duckbill flathead, toadfish, shallowtail bass, hatchetfish, barracudina, bristle mouth, shortnose greeneye, a slope dragonet, and flatfishes. Only five colonies of stylasterid corals were seen throughout the dive.