Hidden Antarctic Ecosystem
Scientists recently gave us our first glimpse of a vast Antarctic ecosystem of microscopic life hidden in under-ice lakes.
For those who have visited Antarctica, or seen photos or videos, it appears as a pretty austere place. Vast spans of ice backed by even vaster spans of ice. But just as the land is dotted with birds and other wildlife, the lakes below the surface are filled with life.
Deep beneath the ice at the bottom of the world, John Priscu, a microbial ecologist from Montana State University in Bozeman and his team, figures out how to extract a sample of water. It wasn’t an easy task and scientists from around the world have been racing to be the first to sample one of Antarctica’s hundreds of subglacial lakes.
Priscu’s water sample came from Lake Whillans, and was trapped beneath half a mile of ice less than 400 miles from the South Pole. That water, obtained on January 28, 2013, was the first sample ever retrieved directly from a subglacial lake.
Priscu and his team reported their findings in a recent issue of Nature. They found an unexpected diversity of life in the isolated lake. Nearly 4,000 species of bacteria and archaea call Lake Whillans home.
“I was surprised by how rich the ecosystem was,” Priscu said. “It’s pretty amazing.”
The reason scientists find so much life surprising is that these species have survived for 120,000 to a million years without sunlight—the basis for most life on earth. Bacteria must depend on organic material that has drifted into the lake from other sources, such as decaying microbes from melting glaciers — or on minerals in the rock of the Antarctic continent.
Darkness isn’t the only odd thing about the lake. According to an article on Nature’s website, “Lake Whillans resembles nothing on Earth’s surface. The weight of the ice forces the subglacial water upwards, causing the lake to sit at a slant on the side of a hill. It is a thin lens of water — only 2 metres (five feet) deep and nearly 60 square kilometres (23-square-miles) in area — held in a pocket of low pressure created by the thinning of the ice sheet as it oozes over the hill.”
The discovery of critters surviving in the dark cold may advance knowledge of how life could survive on other planets or moons.