New Life Discovered in Sediments in Antarctic Subglacial Lake
Deep below the Antarctic ice sheet lie dark and cold subglacial lakes. For years, scientists have wondered whether these freezing bodies of water could hold life, despite the harsh conditions they presented. Now, they may have their answer. Researchers have discovered extreme life forms dating back nearly a hundred thousand years in subglacial lake sediments.
Sampling these buried lakes is not an easy task. Because they lie miles below the thick ice, it's difficult to actually access them. That's why scientists have been searching around the retreating margins of the ice sheet for subglacial lakes that are becoming exposed for the first time since they were buried more than 100,000 years ago.
In this case, the scientists targeted Lake Hodgson on the Antarctic Peninsula. Covered by more than 1,300 feet of ice at the end of the last Ice Age, the lake is slowly emerging from its icy prison. Now, there's a thin covering of a mere 10 to 15 feet. Researchers drilled the ice using clean coring techniques and then took samples from the layers of mud at the bottom of the lake.
"What was surprising was the high biomass and diversity we found," said David Pearce, one of the researchers, in a news release. "This is the first time microbes have been identified living in the sediments of a subglacial Antarctic lake and indicates that life can exist and potentially thrive in environments we would consider too extreme. The fact these organisms have survived in such a unique environment could mean they have developed in unique ways which would lead to exciting discoveries for us. This is the early stage and we now need to do more work to further investigate these life forms."
So what sort of life did they find? They discovered different types of bacteria, including a range of extremophiles. In addition, they found remnants of many species that are likely to be new to science, which makes exploration of the remote lakes isolated under the deeper parts of the ice sheet even more pressing.
The findings give researchers new evidence that life can exist even within extremely harsh conditions. This could, in turn, could have implications for life on other planets.
The findings are published in the journal Diversity.