Microbial life has been found in a lake trapped under 800 metres of ice on the edge of the Ross Ice shelf in Antarctica.
The large wetland ecosystem found in Lake Whillans, a 60 km2 body of water, was reached by the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) science field team from the US using a hot-water drill to penetrate the 800 metres of ice. They finally broke through on 28 January 2013. The scientists used the borehole to collect 30 litres of liquid lake water and eight sediment cores from the lake’s bottom.
Microbes that don’t need sunlight
Both the water samples and sediment cores contained an array of microbes that did not need sunlight to survive. The scientists say that the microbes could get their energy from organic material or from chemical reactions, like the chemotrophs found near deep-sea hydrothermal vents.
The scientists counted about 1000 microbes per millilitre of lake water (about one-tenth the abundance of microbes in the oceans). The microbes will now undergo DNA sequencing and other tests to find out what they are and how they live in a world deprived of light and warmth.
Life on Europa?
Since the discovery of life under the ice, scientists have speculated in various blogs and articles that, if subglacial microbes can survive in such conditions, they might also survive on Jupiter’s moon Europa. Based on imaging from Voyager and Galileo and on theoretical calculations of the tidal pull effect between Jupiter and Europa, many scientists believe that a layer of liquid water exists beneath Europa’s solid ice crust.
Check out the Whillans Ice Stream Subglacial Access Research Drilling website.
If your students are interested in how the microbes discussed in this article live, they may like to read this article, Cold seep communities, that explains the chemical process that allows bacteria to survive in cold seeps.