Dive 11: Vega Baja Landslide
Date: November 11, 2018
Location: Lat: 18.84687°, Lon: -66.39735°
Dive Depth Range: 3,024-3,342 meters (9,920-10,965 feet)


Today we conducted another dive focused on exploring the geology of the region, this time on a landslide scarp located north of Vega Baja, Puerto Rico. Though step-like formations of rock draped heavily with soft sediments were prominent in the beginning, throughout the majority of the dive we observed hard, consolidated bottom with significant ferromangangenses coating. We found little evidence of failures in the rock, as indicated by the lack of freshly exposed surfaces, which may indicate that area is more stable than previously thought.

Soft substrate throughout the dive was composed of pteropod shells, foraminiferan shells, and sponge debris. We only observed six fish species at this location, including two very large individuals of Bathysaurus sp. (> 1 meter in length). Sponges, especially glass sponges, were the most dominant organism at this site.

Echinoderms were the second most common organism seen during this dive. We saw about five species of holothurians, a small stalked and an unstalked crinoid, and four species of sea stars. We also observed quite a few shrimp, small branching bryozoans, a carnivorous tunicate, ctenophores, a tube-dwelling anemone, a corallimorph, a plated polychaete worm, as well as a whale barnacle skeleton.

This fish is Bathysaurus mollis, commonly known as bathysaur or highfin lizardfish, a deep-sea species in the Bathysauridae family. This species is found throughout the Pacific, Indian, and Atlantic Oceans over a wide depth range (1,500-5,000 meters or 4,921-16,404 feet). These deep-sea fish are solitary, lurking bottom feeders that have sharp fangs and strong jaws. The very large individual in this video from Dive 11 of the expedition has ectoparasites on its ventral and caudal fins, which are isopods in the family Gnathiidae.

Text contributed by Daniel Wagner, NOAA Office of Ocean Exploration and Research.

Video courtesy of the NOAA Office of Ocean Exploration and Research, Exploring Deep-sea Habitats off Puerto Rico and the U.S. Virgin Islands. Download larger version (mp4, 78.0 MB).

 


 

Location of Dive 11 on November 11, 2018.

Location of Dive 11 on November 11, 2018. Download larger version (jpg, 2.2 MB).

The remotely operated vehicle track for Dive 11, shown as a white line. Scale is water depth in meters.

The remotely operated vehicle track for Dive 11, shown as a white line. Scale is water depth in meters. Download larger version (jpg, 358 KB).