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Sea Anemones In Antarctica Find A Home On The Ice

January 17, 2014
Image Caption: In an underwater image captured by the robot, Edwardsiella andrillae anemones protrude from the bottom surface of the Ross Ice Shelf. They glow in the camera's light. For purposes of scale, the two red dots in the image measure 10 centimeters apart. Credit: Frank Rack, ANDRILL Science Management Office, University of Nebraska-Lincoln

April Flowers for redOrbit.com – Your Universe Online

A team of scientists and engineers with the Antarctic Geological Drilling (ANDRILL) Program used a camera-equipped robot to explore beneath the Ross Ice Shelf off Antarctica, making an astonishing discovery.

The team found many thousands of small sea anemones that were burrowed into the underside of the ice shelf with their tentacles protruding into frigid water like flowers on a ceiling.

“The pictures blew my mind,” said Marymegan Daly of Ohio State University. Daly studied the specimens retrieved by ANDRILL team members in Antarctica. The new species was discovered in December 2010 and fully described in a recent issue of PLOS ONE.

Other sea anemones have been found in Antarctica, however the new species is the first known to live in ice. The new species live upside down, hanging from the ice, while other sea anemones live on or in the sea floor.

The new anemones, Ewardsiella andrillae, were named in honor of the ANDRILL program. Frank Rack, executive director of the ANDRILL Science Management Office at the University of Nebraska-Lincoln, said that the discovery was “total serendipity.” Rack is also an associate professor of Earth and atmospheric sciences at UNL, as well as the US principal investigator for the environmental surveys that were conducted as part of the international ANDRILL Coulman High project.

“When we looked up at the bottom of the ice shelf, there they were,” he said.

The research team lowered the 4 1/2-foot cylindrical robot equipped with two cameras — a side-mounted lateral camera and a forward-looking camera with a fish-eye lens — into a hole bored through the 885-foot-thick shelf of ice that extends more than 600 miles northward from the grounding zone of the West Antarctic Ice Sheet to the Ross Sea.

The mission of the team was to learn more about the ocean currents beneath the ice shelf and provide environmental data for modeling the behavior of the ANDRILL drill string. They were surprised to discover not only organisms living in the ice, but an entirely new species.

This discovery underlines the fact that even after 50 years of active US research into the region, more remains to be studied about the southernmost continent, according to Scott Borg, head of the Antarctic Sciences Section in the National Science Foundation’s (NSF) Division of Polar Programs.

“Just how the sea anemones create and maintain burrows in the bottom of the ice shelf, while that surface is actively melting, remains an intriguing mystery,” he said. “This goes to show how much more we have to learn about the Antarctic and how life there has adapted.”

Rack had left the site just prior to the discovery, but was listening by radio when he heard the report by the robot deployment team. Engineers Bob Zook, Paul Mahecek and Dustin Carroll began shouting as they saw the anemones, which appeared to glow in the camera’s light.

“They had found a whole new ecosystem that no one had ever seen before,” Rack said. “What started out as a engineering test of the remotely operated vehicle during its first deployment through a thick ice shelf turned into a significant and exciting biological discovery.”

The anemones were not the only discovery. The researchers also saw fish that routinely swam upside down while using the bottom of the ice shelf as the floor of their undersea world, and polychaete worms, amphipods and a creature they called “the eggroll,” a 4-inch-long, 1-inch-diameter, neutrally buoyant cylinder that seemed to swim using appendages at both ends of its body. The eggroll was observed bumping along the field of sea anemones under the ice and hanging on to them at times.

E. andrillae measured less than an inch long in their contracted state, and three to four times longer in their relaxed state. Daly noted that each anemone featured 20 to 24 tentacles, an inner ring of eight longer tentacles and an outer ring of 12 to 16 tentacles.

The team used hot water to stun the anemones, then an improvised suction device to retrieve them from their burrows. They transported the anemones back to McMurdo Station for preservation and further study.

The original mission had not been to hunt for biological specimens, so the team was not equipped with the proper supplies to preserve the samples for DNA/RNA analysis. At the drilling site, the anemones were placed in ethanol, and some were later preserved in formalin at McMurdo Station.

Many questions remain to be answered. Some anemones burrow into sand with their tentacles, or expand and deflate the base of their bodies to burrow. These methods, however, do not seem suited to ice. The scientists say it is also unclear how the anemones survive without freezing and how they reproduce. No evidence of what they feed on has been found, although Daly says that most likely they feed on plankton.

The team is preparing a proposal for further study of this unusual environment using a robot that would allow them to explore deeper into the ocean and farther away from the access hole through the ice. Because the discoveries made in the Antarctic have implications for the possibility of life existing on Europa, the ice-covered moon of Jupiter, NASA is helping to fund the development of the new robot.

Rack said that the team hopes to return to Antarctica as early as 2015 to continue studying the new species and other organisms beneath the ice shelf.


Source: April Flowers for redOrbit.com - Your Universe Online



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