Antarctic ice shelves teeming with life, study finds

Written by Oceanographic Staff

Deep down below the Antarctic ice shelves, more marine life can be found than previously expected.

Complete darkness and extremely cold temperatures are the conditions most associated with the seabed deep down below Antarctica’s Ekström Ice Shelf. A recent study, published in the journal Current Biology, now argues that a thriving ecosystem that has existed for thousands of years lives beneath these Antarctic ice shelves.

Antarctic ice shelves, despite covering almost 1.6 million km2 of the planet, have not been studied extensively as the seabeds underneath these colossal ice masses are considered some of the planet’s least known and harshest environments.

To offer some insights into what lives under Antarctic ice shelves, a team of researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research in Germany, used hot water to puncture two nearly 200-metre-deep holes through the Ekström Ice Shelf in the South Eastern Weddell Sea in 2018.

The findings were both surprising and exciting. While cameras have filmed some marine life under Antarctic ice shelves before, extensive research like the one conducted by the German team has not been done. In total, 77 species were found, including some moss animals such as Melicerita obliqua and serpulid worms such as Paralaeospira sicula. All creatures were found to be suspension feeders which means that they stay put in a certain place and use their feathery tentacles to grab organic matter from the water flowing around them.

“This discovery of so much life living in these extreme conditions is a complete surprise and reminds us how Antarctic marine life is so unique and special. It’s amazing that we found evidence of so many animal types, most feed on micro-algae (phytoplankton) yet no plants or algae can live in this environment. So the big question is how do these animals survive and flourish here,” says lead author Dr David Barnes, a marine biologist at British Antarctic Survey.

Co-author Dr Gerhard Kuhn adds: “Another surprise was to find out how long life has existed here. Carbon dating of dead fragments of these seafloor animals varied from current to 5,800 years. So, despite living 3 to 9 km from the nearest open water, an oasis of life may have existed continuously for nearly 6,000 years under the ice shelf. Only samples from the sea floor beneath the floating ice shelf will tell us stories from its past history.”

Unfortunately, the team of researchers also highlight the urgency to protect these important ecosystems. “It may be cold, dark and food-scarce in most places,” the team writes, “but the least disturbed habitat on Earth could be the first habitat to go extinct as sub-ice shelf conditions disappear due to global warming.”

For more from our Ocean Newsroom, click here.

Photography courtesy of Unsplash.

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