Scientists have discovered a deep sea ecosystem dominated by hairy pale crabs off of Antarctica. The new species of “Yeti crabs” survive alongside many other likely new species, including a seven-armed meat-eating starfish, off of hydrothermal vents, which spew heat and chemicals into the lightless, frigid waters. According to the paper published in PLoS ONE, this is the first discovery of a hydrothermal vent ecosystem in the Southern Ocean though many others have been recorded in warmer waters worldwide.
“Hydrothermal vents are home to animals found nowhere else on the planet that get their energy not from the Sun but from breaking down chemicals, such as hydrogen sulphide,” explains lead author, Alex Rogers of Oxford University’s Department of Zoology, in a press release. “The first survey of these particular vents, in the Southern Ocean near Antarctica, has revealed a hot, dark, ‘lost world’ in which whole communities of previously unknown marine organisms thrive.”
Scientists reached the hydrothermal vents in the East Scotia Ridge of the Southern Ocean via a Remotely Operated Vehicle (ROV). Besides capturing photos of ghostly crabs linings every inch of some of the vents, the ROV also took images of likely new species of barnacles, limpets, snails, sea anemones, starfish, and maybe even an octopus. The new species, which are believed only to survive in Antarctic waters, live around chimneys up to 15 meters (49.2 feet) tall and as hot as 352.6 degrees Celsius (666.6 degrees Fahrenheit).
"What we didn't find is almost as surprising as what we did," said Rogers. "Many animals such as tubeworms, vent mussels, vent crabs, and vent shrimps, found in hydrothermal vents in the Pacific, Atlantic, and Indian Oceans, simply weren't there."
The authors believe the new species discovered in Antarctica "[represent] a separate and new biogeographic province from those previously described for the global ocean." In other words, the researchers theorize that the new species have created a unique animal community that is endemic to Antarctic waters and doesn't mix with other hydrothermal vent communities in the north.
"The Southern Ocean is separated from the remaining global ocean by the surface-to-seabed Polar Front, which is a major barrier to dispersal of fauna to and from Antarctic waters. This region represents a sharp boundary in physical conditions," the authors write, noting that many Antarctic marine species are believed endemic to the Southern Ocean.
Hydrothermal vent ecosystems have only been known to marine scientists for around 35 years. Their initial discovery in the Galapagos Rift astounded scientists, who did not expect deep sea marine life to be able to exist in such densities. Further understanding of how the species exploit the chemicals produced by the vent have given rise to new theories on the origins of life. This new discovery is certain to bring about more questions.
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