Sidescan sonar showed a cluster of large structures at a depth of 1,900 meters (6,234 feet) in the Gulf of Mexico. So as NOAA explorers participating in the Exploration of the Gulf of Mexico 2014 expedition steered remotely operated vehicle Deep Discoverer to the bottom, thinking that they would be approaching the wreck of a sunken ship.
Within minutes of observing the first part of the suspected shipwreck, however, it became clear that the feature was not human-made, but a natural phenomenon that was eventually nicknamed a “tar lily.”
Discussion between the shore and the ship zeroed-in on the likeliest explanation — that this feature was a flower-like extrusion of asphalt at the seafloor — the first of its kind documented in this area of the Gulf of Mexico. Each “petal” of the tar extrusion or “flower” was curved and had internal layering, a result of de-volatilization of the asphalt rising from the sub-seafloor upon its contact with seawater.
The first “tar lily” that was explored was colonized by fly trap anemones, unidentified sponges, goose neck barnacles, octocorals, sea pens, squat lobsters, and bamboo corals. There were also a few chemosynthetic fauna, including tube worms, bacterial mats, and Alvinocaris shrimp. At the second “tar lily,” there were more chemosynthetic worms, a spiral coral, a few octocorals, and several branching bamboo corals.
Download SD version (mp4, 29.1 MB).
Video courtesy of NOAA Ocean Exploration, Exploration of the Gulf of Mexico 2014.