April 15, 2008
Gulf of Mexico Coral Expedition – Part Three
BY: Margot
The main drawback of joining a cruise part way through is that you begin the trip with stories of the amazing things that everyone saw just before you arrived. This cruise is no exception. Before I got here, the ship went to Pulley Ridge and a series of similar ridges south of here on Florida’s Gulf Coast. In addition to the array of deep and shallow water corals, fish of all kinds including snapper and grouper, the ROV pilot and scientists saw something they’ve never seen before. As the robot cruised along the bottom, they came across a loggerhead turtle which appeared to be resting among the sponges and sea fans. I always liked turtles but knowing that they take naps makes me like them even more. The Gulf of Mexico is full of sea turtles, but to come across one sleeping on the seafloor rather than swimming at the surface is a surprise; an excellent reminder of the many connections between different components of the ecosystem.Today’s dives left no disappointment. Up at 0630, I am glad to skip the commute and go straight to breakfast in the galley. At 0730 we are on deck lowering the CTD over the side of the ship with a huge orange crane for a snapshot of basic ocean conditions including the conductivity, temperature, and depth that give the CTD its name.Next is the first ROV dive. This time I watch from inside the dry lab to get the ROV’s eye view instead of watching from behind the engineer who works the crane. It is lowered over the side with a splash into the swell and the screen fills with bright blue broken by streams of bubbles as we sink towards the bottom. The lower left-hand corner depth meter marks our progress in the shades of blue grow darker, 70 feet, 112 feet, 130 feet, 145 feet… we continue to the prearranged depth estimated from the charts. The ROV pilot doesn’t see the bottom so he radios the crane operator to lower more line. A pattern of light and dark swatches materializes from the haze and abruptly we land just above the sand. The ship is still on the move, and in a second we are also underway, as the ROV pilot gains his bearings and begins to drive along just above the seafloor.Today we are in and around the Madison – Swanson area, which is partially protected and currently being considered for additional conservation measures. This location is famous to me because of a breathtaking photo of a coral bouquet that appears in many of our reports, which I keep as a talisman of why I work on conservation. Today we revisit the location of this semi-famous photo and I suddenly recognize that it is only a glimpse of this much larger area covered in sea fans the color of hot peppers, lemons, and watermelons. Hungry basket stars chew on the outer branches of many of the sea fans, each a cluster of convoluted arms. We also get a close-up with a puffer fish, the kind that inflates into a round spiky ball. Left and right shiny red bigeye fish dive into holes as we pass. And yes, they have big eyes. Another coral that is famous in the world of deep sea conservation, Lophelia pertusa, makes its appearance later on. Lophelia is one of the few stony reef-building corals that can grow at depths below the reach of sunlight. In Norway and on the Atlantic Coast of the Southeast US it grows into tall and extensive reefs, which Norway protected almost immediately after their discovery as the first deep sea coral conservation effort in the world. The US still lags behind. Lophelia reefs in the Southeast US have been recognized and their protection will be voted on in the next few months at the South Atlantic Fishery Management Council. Here in the Gulf of Mexico and on today’s dives we see only small Lophelia colonies, but it is exciting just the same. The pilot hovers for a moment and zooms in close so we can actually see feeding tentacles outstretched like transparent fingers. The white cups of its skeleton are clearly recognizable. Watching this Lophelia coral feed is a keen reminder that corals are animals too, and rely on consuming microscopic organisms for food. After a moment we must flit onward, swooping forward again as we “fly” with the ship.
