Scientists say the underwater plumes -- located between the southern tip of South America and the Antarctic Peninsula -- are chock-full of new species, including a pale, ghostly-looking octopus, a predatory seven-legged sea star and a hairy-chested "yeti" crab.
Experts say the strangest thing is what they didn't find -- tube worms, shrimp and mussels that have been found at the world's other deep-sea hydrothermal vent communities.
"It wasn't just one creature, virtually everything we saw was new to science," said Alex Rogers, professor zoology at the University of Oxford and lead author of the new report.
"It was a remarkable experience. You're not quite sure if these things are mineral or biological structures. That's a very unusual feeling to see all this stuff for the first time and saying I don't understand what's going on here."
Rogers and his colleagues at the University of Southampton described their findings in today's PLOS Biology.
The discoveries came during a January and February 2010 expedition to the region and were made using a remote-operated vehicle (ROV) called Isis.
Rogers said it took nearly two years to get the findings published because there were so many undescribed species that his team had to send samples out to experts around the world for identification.
He recalled watching a small video screen on board the British oceanographic vessel James Cook as the ROV camera descended 2,600 meters (8,530 feet) down to the seafloor.
"The robot camera captured images of smoking plumes of hydrogen sulfide and minerals billowing up from fissures in the undersea ridge up to 382 degrees Celsius (720 degrees Fahrenheit) and surrounded by vast living mats of barnacles, anemones, crabs and other critters."
"It's probably the most exciting scientific cruise I've ever taken part in," Rogers said from his office in England.
"The wonderful thing was that the discoveries just kept coming right through the trip. Seeing the images for the first time was absolutely breathtaking, just stunning."
But beyond the giddy excitement of finding new animals, marine biologists say that the mix of deep-sea fauna at these vents will stir debate about how these creatures got there.
"The Rogers paper fills in a piece of the bio-geographic puzzle for global vent faunas and raises new questions about evolutionary alliances and pathways to hydrothermal vents," said Cindy Van Dover, director of the Duke University Marine Laboratory, and a leading expert in undersea hot springs biology, in an email to Discovery News.
"Their discovery of dense populations of crabs related to the yeti crab is especially intriguing. This family of crabs was discovered in 2005 at hot springs in the southeastern Pacific -- there must be an evolutionary link between the two regions."
That means that the creatures living at underwater hot springs must be able to colonize other vents, even though the plumes often are short-lived, lasting only a few decades before the seafloor shifts and the hot springs disappear.
Another big question is whether the extremely cold water that circles Antarctica helps or hinders dispersal of the larvae of the strange life that thrive at the vents.
"Depending on the group of deep-sea organisms, the Southern Ocean can be an ecological dead end or a jumping-off point for colonizing other parts of the world," said Rich Aronson, head of the department of biological sciences at the Florida Institute of Technology who studies Antarctic undersea life.
Read more at Discovery News
No comments:
Post a Comment