LSU associate professor on team studying life in Antarctic lake

It’s dark, it’s cold, it’s largely cut off from the outside world, but the lake water under a half-mile of ice in Antarctica is teeming with microbial life.

That discovery is the focus of an article in the most recent Nature magazine published Thursday.

“Antarctica, it’s the coldest place on the planet,” said Brent Christner, LSU associate professor of biological sciences and lead author of the report.

The coldest temperature measured on Antarctica was down to 130 degrees below zero, he said.

“Doesn’t seem like an ideal place for life,” he said; however, the lakes underneath the ice actually are an oasis for life.

The ice that covers Antarctica hides a large system of lakes, rivers, estuaries and other water bodies. Imagine, Christner said, if you took coastal Louisiana and then put a half-mile of ice on top of it. All of those water features still would exist and still function, but it’s just hidden.

Lakes form as the ice on top of it melts through the heat put off by the Earth. The large layer of ice acts like a blanket trapping that heat, which in turn melts the ice underneath, creating the network of lakes and rivers.

For the current project outlined in the Nature article, research scientists drilled through the ice, down to the lake and took samples of the water for further study. Looking at the DNA contained in those samples, researchers identified about 4,000 separate microbial species.

This is the first time that one of these subglacial lakes has been sampled directly, he said. A previous project that involved drilling in Lake Vostok took samples of refrozen lake water but not the water itself.

Although those samples showed microbial life, there were questions about the drilling technique that used kerosene to help keep the drill pipe pressurized.

In this more recent project at Whillans Lake, the team used a clean hot-water drill and took other precautions against contaminating the samples.

What they found surpassed what they had been expecting based on results from the Lake Vostok work with thousands instead of hundreds of different microbes showing up in results. So without sunlight, how does this system of life exist? Scientists say the moving ice overhead pulverizes the rock it is sliding along, which releases minerals into the water. Microbes use these minerals as their energy, turning out waste products that other microbes use as energy.

Just how this is done, and which microbes do which jobs, is the topic of future research.

This current National Science Foundation-funded Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project included 12 co-principal investigators from as many institutions along with a host of graduate and doctoral candidate students. In total, there were 46 researchers on the ice of western Antarctica for the four days the research work was going on.

“We were the third biggest settlement on Antarctica,” Christner said.

The site of Whillans subglacial lake is about 600 miles from the group’s base station at McMurdo Station. The approximately million pounds of equipment to do the drilling and research took the two-week journey over the ice, while most of the scientists and more fragile equipment was flown into the area later, Christner explained.

It took four, suspense-filled days for the drilling work to get done and was made even more nail-biting because a neighboring expedition had to pack up and go home after their drill got stuck in the ice before reaching the lake.

When the WISSARD project team saw its drill bit break through into the lake, there was a huge sense of relief and excitement that the work could continue.

The team then had four days to do its work, which included the use of a microbiology laboratory on site. With time being short, the team worked 24 hours a day, aided by the fact that the sun never went down, said Amanda Achberger, a doctoral candidate and a researcher on the project.

The next excitement of the trip for Achberger was once she got a chance to look for DNA in the samples. When she started finding that DNA, she knew they were on their way to finding what previous research had hinted they would find — life.

Achberger will be continuing the research to sequence the DNA, which will show just what types of microbial life they found and how each of these function in the ecosystem.

“It’s really a food web that is microbial,” she said.

Achberger, Christner and others will be heading back out in January to drill in a different spot to sample pools of water more in the ocean salinity range to see what they can find.

Follow Amy Wold on Twitter, @awold10.