The Final Dive

October 1, 2003

atalina Martinez
NOAA Office of Ocean Exploration

The final ROV (remotely operated vehicle) survey of the expedition took place at the Mississippi Canyon 885 (MC 885) site. Similar to the other deep dives on this cruise, the main objective of this dive was to locate communities of Lophelia in association with authigenic carbonate rock outcroppings. Although previous explorations to this site documented many sightings of Lophelia, the dominant coral species found during today's 9.5-hr dive were Callogorgia and Madrepora sp. The survey site was mostly mud, punctuated by fields of gorgonians of varying densities. The two species of gorgonians were found in association with large numbers of brittle stars. One small region with Lophelia was discovered, but the dominant coral at this site was Madrepora. The other highlights of the dive included gallatheid crabs, white sea stars, cup corals, and a redeyed gaper fish.

Callogorgia coral along with a solitary cup coral

This image of Callogorgia coral with a solitary cup coral is from video footage of the last ROV dive at Mississippi Canyon. Click image for larger view.

A large Madrepora coral along with Primnoa coral seen in the pictures lower left corner

This large Madrepora coral was a common site at Mississippi Canyon. Note the Primnoa coral in the lower left foreground. Click image for larger view.

The ROV recovery from this dive was the most difficult yet, as the winds and seas had increased tremendously during the course of the dive. Although the massive sub swung wildly in the air at one point, the Sonsub crew brought the Innovator safely back on deck, incurring only superficial damage. Since the weather was predicted not to improve, the scientists and crew decided it was time to head for shore. The conditions were simply too dangerous to attempt another dive during the 24-hr period remaining in the expedition.

Wind and waves building during the last dive

Wind and waves build during the last dive at Mississippi Canyon. Click image for larger view.

During the transit to Gulfport, Mississippi, the scientists, crew of the NOAA Ship Ronald H. Brown, and crews of Sonsub, Inc. and C&C Technologies will prepare for the Open House scheduled for Friday, October 3. The ship will host a media event and give tours to local schoolchildren and teachers. Scientists will display the samples they collected during the expedition, and will tell students all about the exciting deep-sea habitats located right in their own "backyard" -- the vast and enigmatic Gulf of Mexico.