'Lost World' of sea creatures discovered near Antarctica
A "lost world" of sea creatures was discovered near Antarctica,
British scientists announced Wednesday. Scientists doing their first
exploring of deep-sea vents in the Antarctic said it was unlike anything
found around other hydrothermal vents - a world populated by new species
of anemones, predatory sea stars, and piles of hairy-chested yeti crabs.
It was "almost like a sight from another planet," said expedition leader
Alex Rogers, a professor of zoology at Oxford University.
Even in the eye-popping world of deep-sea vents, the Antarctic
discoveries stand out, with the unfamiliar species of crabs found
crowded in piles around the warm waters emanating from the seafloor.
Many of the animals found at the vents have never been found at
hydrothermal vents in other oceans, Rogers said. "To see these animals
in such huge densities was just amazing," Rogers told LiveScience. In
the dayless world of deep-sea vents, energy comes not from the sun but
from the hydrothermal energy generated in the oceanic crust. The yeti
crabs seem to cultivate "gardens" of bacteria on their chests, which are
covered with hairy tendrils. These bacterial mats almost certainly
provides the crabs with sustenance, Rogers said. In turn, predatory
seven-armed sea stars stalk the periphery of the vents, snacking on
unfortunate crabs. [See video and photos from the vents] "We were
absolutely stunned to see the animal communities, because they were so
different from the hydrothermal vents seen elsewhere," Rogers told
LiveScience.
He and his colleagues reported their results today (Jan. 3) in the
journal PLoS Biology. Discovery in the deep sea Weird life flourishes at
deep-sea vents the world over, but no one had ever found hydrothermal
vents in Antarctica, explained Jon Copley, a professor of earth and
ocean science at the University of Southampton who also participated in
the research. That's largely because it's more difficult to do research
in the harsh Southern Ocean than in temperate climes. [Extremophiles:
World's Weirdest Life] "It's only quite recently that we've been able to
be bold enough, really, to head to the poles," Copley told LiveScience.
In 1999, Antarctic mapping surveys turned up hints of hydrothermal vent
output in the water column over the East Scotia Ridge in the Atlantic
section of the Southern Ocean, between Antarctica and South America and
eastward. It took 10 years for researchers to get back for a full-blown
expedition, during which they lowered cameras to two areas, 8,530 feet
(2,600 meters) and 7,874 feet (2,400 m) deep, catching the first
glimpses of Antarctic hydrothermal vents. Among them were "black
smokers," chimney-like vents that emit dark-hued, superheated water.
Although the background temperature of the Southern Ocean in the area is
32 degrees Fahrenheit (0 degrees Celsius), the black smokers gushed
water as hot as 721 degrees F (382 degrees C). In 2010, the researchers
returned with a remote-operated submersible vehicle (ROV) called Isis.
The sub took close-up photos of the amazing vent fauna and collected
samples of organisms for identification. New world Among the new species
were the yeti crabs, crowded around the vents up to 600 per square
meter. "They're literally, in places, heaped up upon each other," Rogers
said. Crabs normally don't tolerate cold temperatures well, so the vents
may be a warm haven for these crabs, Copley said.
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