Life brimming with active ecosystem beneath Antarctic ice
A lake that has not seen sunlight or felt a breath of wind for millions of years beneath the Antarctic ice is brimming with life and active ecosystem, reveal findings of a massive US expedition.
The life is in the form of microorganisms that live one-and-a-half mile below the surface of the West Antarctic Ice Sheet and convert ammonium and methane into the energy required for growth.
"We were able to prove unequivocally to the world that Antarctica is not a dead continent. Many of the microbes are single-celled organisms known as Archaea," said Montana State University professor John Priscu.
Priscu is the chief scientist of the US project called the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) that sampled the sub-ice environment.
It is the first definitive evidence that there's not only life, but active ecosystems underneath the Antarctic ice sheet, something that "we have been guessing about for decades", said lead author Brent Christner from Montana State University.
To prove that an ecosystem existed below the West Antarctic Ice Sheet, Priscu wanted at least three lines of evidence.
They had to see microorganisms under the microscope that came from Lake Whillans and not contaminated equipment.
They then had to show that the microorganisms were alive and growing.
Lastly, they had to be identifiable by their DNA.
"When we found those things, we knew we had succeeded," Priscu said.
Scientists are excited to see how the microbes function without sunlight at subzero temperatures and the fact that evidence from DNA sequencing revealed that the dominant organisms are archaea.
Archaea is one of three domains of life, with the others being Bacteria and Eukaryote.
Priscu also noted that as Antarctica continues to grow warm, vast amounts of methane, a potent greenhouse gas, will be liberated into the atmosphere enhancing climate warming.
The WISSARD project began in 2009 with a $10 million grant from the National Science Foundation.
The study appeared in the journal Nature.
(Posted on 21-08-2014)