Tuesday, January 31, 2012

[Geology2] Antarctic seafloor geyser found hosting strange community

I love when that happens . . .
Antarctic seafloor geyser found hosting strange community


Species previously unknown to science have been discovered on the
seafloor near Antarctica, clustering in the darkness around seafloor
geysers called hydrothermal vents, scientists say. The findings, made by

teams led by the University of Oxford, University of Southampton and
British Antarctic Survey, include new species of crab, starfish,
barnacles, sea anemones, and potentially an octopus.

For the first time, researchers have used an underwater robot to explore

the so-called East Scotia Ridge deep beneath the Southern Ocean, where
hydrothermal vents, create a unique environment that's
pitch-black but rich in certain chemicals. The vents include
"black smokers" named after the dusky substances that
issue from their hot spouts, which reach temperatures of up to 382
degrees Celsius (720 Fahrenheit).

The scientific team reports its findings in this week's issue of

the online research journal PLoS Biology. "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," said Professor Alex Rogers of Oxford
University's Department of Zoology, who led the research. "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."

Highlights include images showing huge colonies of the new species of
yeti crab, thought to dominate the Antarctic vent ecosystem, clustered
around vent chimneys. Elsewhere the robot spotted numbers of an
undescribed predatory sea-star with seven arms crawling across fields of

stalked barnacles. It also found an unidentified pale octopus, nearly
2,400 metres down, on the seafloor. "What we didn't find

is almost as surprising as what we did," said Professor 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 team believe that the differences between the groups of animals
found around the Antarctic vents and those found around vents elsewhere
suggest that the Southern Ocean may act as a barrier to some vent
animals. The unique species of the East Scotia Ridge also suggest that,
globally, vent ecosystems may be much more diverse, and their
interactions more complex, than previously thought.

In April 2011 Professor Rogers was part of an international panel of
marine scientists who gathered at Somerville College, Oxford to consider

the latest research on the world's oceans. A preliminary report
from the panel in June warned that the world's oceans are at
risk of entering a phase of extinction of marine species unprecedented
in human history. "These findings are yet more evidence of the
precious diversity to be found throughout the world's
oceans," said Professor Rogers. "Everywhere we look,
whether it is in the sunlit coral reefs of tropical waters or these
Antarctic vents shrouded in eternal darkness, we find unique ecosystems
that we need to understand and protect."

The discoveries were made as part of a consortium project with partners
from the University of Oxford, University of Southampton, University of
Bristol, Newcastle University, British Antarctic Survey, National
Oceanography Centre, and Woods Hole Oceanographic Institution.


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