A lone octopus wends her way across the floor near a hydrothermal vent 7,800 feet below the surface of the Antarctic Ocean.
She’s just one of thousands of sea creatures seen by humans for the first time when a team from Oxford University sent a remote camera down to visit them.
These yeti crabs have hairy chests rather than the hairy claws of their Pacific relatives. The scientists think the crabs grow bacteria on the hairs and somehow derive nutrients by harvesting the microbes.
“They literally occur in heaps,” said Professor Alex Rogers of Oxford University’s Department of Zoology, who led the team. “And they look quite sinister because from a distance with their very pale white color they almost look like a big pile of skulls on the seabed.”
They had been expecting to find similar life to other vents in the Atlantic and Indian oceans. Instead what they discovered was a unique world which may have existed in isolation for the last 15 million years.
The surprises were not only the creatures no one had seen before, but also the absence of deep sea creatures that are common at other hydrothermal vents – probably because these newfound vents are surrounded by the icy polar waters.
“Many animals such as tube worms, vent mussels, vent crabs, and vent shrimps, found in hydrothermal vents in the Pacific, Atlantic, and Indian Oceans, simply weren’t there,” Dr. Rogers said. “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.”
Temperatures are super-hot in the chimney-like vents and super-cold in the surrounding frigid ocean, leaving the waters rich in certain chemicals that support life.
To reach the region above these volcanic vents, the team had to brave severe storms and 30-foot swells on the East Scotia ridge which runs under the Southern Ocean to Antarctica.
There are up to 55 yeti crabs per square foot. “There were literally heaps and heaps of them,” Dr. Rogers said.
These sea stars have seven legs, rather than the usual five.
These are the “black smoker” vents that are home to all these animals and plants.
Chemical-laden water exits the seabed through vents, hitting cold seawater and causing metallic sulfides to precipitate.
A large anemone
Stalked barnacles cling to the rocks and wave their arms in search of food.
A stalked crinoid devil’s punchbowl.
“These findings are yet more evidence of the precious diversity to be found throughout the world’s oceans,” Dr. Rogers said. “The fact you can totally change your ideas about how these systems are distributed round the world in the space of an 8 week cruise really shows how poor our understanding of them is.
“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.”
Here’s the full report of the team.