Mission Blue: Test Dive at Roughtongue Reef
January 6, 2011
National Geographic Explorer-in-Residence Sylvia Earle and Harte Research Institute ecologist Thomas Shirley describe plans for their first dive of the expedition in the Waitt Institute’s two-person Deepworker sub at Roughtongue Reef, part of the “string of pearls in the top of the northern Gulf.”
The two-person Waitt Institute’s Deepworker sub with hatches up before departing from Pensacola.BY SYLVIA EARLE and THOMAS SHIRLEY
SHIRLEY: When we descend in the Deepworker, we hope to find ourselves near the Medusa lander–Edie Widder and ORCA’s photographic landing module–and then to swing by and take videos of that. We’ll keep our video cameras running, and hope to run one or two transects across the top of Roughtongue Reef, then go over the southwest edge downslope to the bottom, which is not a lot of vertical relief–probably ten meters max.
The reason we’re going over that area is because it’s the area of highest prevalent current, and there should be a lot of suspension feeders. By that, I mean primarily sponges, and octacorals, deep corals.
EARLE: We are prepared to take sediment samples if we can find a nice soft-bottom area, and water samples for sure, the goal being to try to determine whether there’s evidence of the spill in this area. The spill certainly drifted right through this place. The question is: are there detectable signs of it right now?
The Deepworker’s claw and bucket permit the retrieval of specimens during a dive. The sub can also collect sediment cores and water samples.SHIRLEY: This area lies within the probability cone of exposure to the oil spill. We’ll take samples of the sediment, water, and some tissue samples, primarily of the corals, to see if there’s any evidence of exposure to the oil.
EARLE: And we’re certainly going to look around and see who’s there. These so-called topographic highs, these places that some have referred to as a string of pearls in the top of the northern Gulf, they’re places where fish tend to congregate. Other forms of life, too. They tend to have a hard substrate as compared to the surrounding soft substrate, and it gives corals, sponges, and a lot of things a place where they can sit down and get started. So they’re deep coral reefs, basically, deep reefs of life.
Going forward, we hope to go much deeper than this. This is probably the shallowest dive that we intend to make. This is still within the range of life, so we might even find some seaweed down there, depending on how clear the water turns out to be.
Lasers, a video camera, and bright lights are mounted at the front of the Deepworker sub.SHIRLEY: There should be a lot of snapper–red snapper should be prevalent. There might be a few gray snapper, but also grouper. More females in this area: It’s not deep enough for the really large males to show up. And there will be a lot of small tropical fish in this area, simply because of the hard substrate, subtropical.
EARLE: The currents from the Caribbean reach as far up as we are here during the right times, and they’re bringing the young stages of tropical and subtropical creatures far into the northern Gulf. It was so unexpected when coral reefs were first discovered in the northern Gulf of Mexico back in the seventies. Well, fishermen perhaps knew about them earlier, but the first scientific records really began in the seventies of real corals growing this far north. The Flower Garden Banks National Marine Sanctuary is one of those special places that has been designated.
One of the things that we certainly are on the lookout for is places that we might be able to recommend for protection as sources of renewal from the spill that happened in 2010. We are hoping that policies will be developed that will essentially give back to the Gulf and restore the health, maintain the integrity of systems that have been degraded, not just because of the recent oil spill, but by years of overfishing, of shore-based pollution that has affected–or you could say afflicted–the Gulf of Mexico over time.
This spill was just the latest in a long list of issues that, perhaps, having protected areas could help address by providing greater stability and restoration of systems that have degraded over time. So we have kind of a double mission: One, to identify if we can the impacts of this recent spill. But also to look for reasons for hope in places that are in good shape.
Roughtongue Reef is not in protected waters, but it could be if we see that the fish are, as we anticipate, gathering there. If this is a place that’s a haven for them, we should keep it that way, and perhaps encourage maintaining this as a place where fish can recover from the many problems that they’ve faced over the last few decades.
The Deepworker sub’s shipping crate doubles as an office, a toolshed, “and Starbucks,” says operations manager Ian Griffith, while the sub awaits deployment on deck.Support for the Mission Blue Gulf of Mexico expedition is provided by the National Geographic Society, Google Inc., the Waitt Institute, and Hope Spots LLC. Follow along in context by clicking on the ship icon near Pensacola, Florida using Google Earth.
Read all Mission Blue expedition coverage here.
Photos by Ford Cochran
