Volcanic vents on the Southern Ocean sea floor are host to whole new communities of animals previously unknown to science. New species include starfish, barnacles, sea anemones, a yeti crab and possibly an octopus.
Using a Remotely Operated Vehicle (ROV), researchers from the University of Oxford, University of Southampton and British Antarctic Survey explored the East Scotia Ridge, an area where hydrothermal vents reach temperatures of 382°C. The environment is unique as it lacks sunlight and animals are dependent upon chemicals released by the vent as an energy source.
"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."
The ROV was able to provide images of huge colonies of the new species of yeti crab (pictured at the top of the page) thought to be the dominant animal of the Antarctic vent ecosystem. The ROV was also able to capture images of an undescribed seven-armed predatory sea-star, and an unidentified pale octopus found on the seafloor at a depth of nearly 2,400m.
The absence of some species was also significant as it suggests that the Southern Ocean may act as a barrier to some vent animals.
"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."
Professor Rogers was part of an international panel that met in April 2011 to consider the latest research on the world's oceans, resulting in a preliminary report warning of an extinction phase of marine species that is 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 team reports its findings in the online, open-access journal PLoS Biology.
For further information and more images of species mentioned here, see the paper: Rogers AD, Tyler PA, Connelly DP, Copley JT, James R, et al. (2012) The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography. PLoS Biol 10(1): e1001234. doi:10.1371/journal.pbio.1001234
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