The fluids that escape from hydrothermal vents can reach 720 degrees Fahrenheit. (Photography: NERC/NSF Chesso consortium)
Deep in the Southern Ocean near Antarctica, scientists have discovered 23 new animal species living in the hot, dark environment around hydrothermal vents.
This deep-sea ecosystem was dominated by a species of yeti crab, but also included stalked barnacles, limpets, snails, sea anemones and possibly an octopus, the scientists report in the journal PLoS Biology. There will be more new species discovered as the collected material is further evaluated, said Alex Rogers, a marine biologist at the University of Oxford in England who took part in the expedition.
“What we actually found is a community that looked quite different from anything else,” Dr. Rogers said.
Fauna typically found in hydrothermal vents in the Pacific, Atlantic and Indian Oceans — like tube worms, mussels and shrimp — were missing in the Antarctic vents.
“We were expecting to see some of them,” Dr. Rogers said. “But the harsh conditions of the Antarctic probably select against some of these animals.”
The researchers used a remote-controlled vehicle that dived about 8,000 feet to gather images and samples from the sea floor.
The water temperature at that depth is barely above freezing, but the fluids that escape from the hydrothermal vents can reach 720 degrees Fahrenheit.
“No animal can actually survive at that temperature, so they tend to live on the interface in between,” Dr. Rogers said.
The greatest concentration of animals was found in waters that were about 50 to 68 degrees.
Worldwide, more than 700 species have been discovered near hydrothermal vents. About 75 percent of those are thought to occur only around vents, Dr. Rogers said, fueled by chemicals like hydrogen sulfide that issue from the vents.
“These communities are so special because they rely on chemical energy rather than light energy from the sun,” Dr. Rogers said.
Author: Sindya N. Bhanoo
Source: The New York Times