Scientists discover new species in ocean's depths

Until last December, no one had ever seen the bottom of the Tasman Fracture, a trench that drops more than four kilometers below the surface of the ocean. A group of Australian and American researchers recently spent a month hundreds of kilometers southwest of the Tasmanian coast, exploring the fracture's depths.Jess Adkins, a professor at Caltech and one of the project's lead scientists, remembers sitting in his control room and watching the underwater life on his monitors with a sense of awe. Once, he says, none of the scientists or pilots said a word for 10 minutes straight as their submersible glided over an undiscovered coral reef full of urchins and sponges and sea stars. The researchers explored the fracture with Jason, a remotely-operated submersible the size of a small car. On loan from the Woods Hole Oceanographic Institute, it carried a high-definition camera that weighed more than 500 pounds and beamed underwater video up to the ship through a long fiber-optic tether. At 3,000 meters below sea level, the crew saw thousands of sea spiders. At 3,500, millions of specimens of a new, purple-spotted sea anemone. At 4,000 meters, a single never-before-seen carnivorous sea squirt with a funnel-shaped body that snapped shut like a Venus flytrap around any shrimp unfortunate enough to brush against it. Back on land, the three new species (the anemone, the sea squirt, and a new kind of barnacle) have drawn the most attention, but it's the team's coral collection, some 10,000 pieces of it, that can tell us about the history of our climate and, perhaps, its future. A coral skeleton acts as a tape recorder of its environment. As it grows, the coral's chemical structure (specifically the weight of its oxygen molecules) varies depending on the temperature of the water around it. And, because the coral's uranium decays into thorium over time, it is conveniently datable.By charting different corals' ages and oxygen weights, researchers can map the ocean's changing temperature. During the coming months, expedition scientists will compare 40,000 years of oceanic and atmospheric records.