At the heart of the dispute is a small but diverse group of microbes found in the single core that has been drilled from the ice above the lake. The Russians and French say these are contaminants from the drilling and testing of samples in the labs. They also argue that the lake itself is too toxic to sustain life because of its extremely high levels of oxygen. If they are right, it would be the first lifeless water body found on Earth. As such, it could help us hone our techniques for the search for life under the polar ice caps on Mars, and in the oceans under the frozen surface of Jupiter's moon Europa. Lake Vostok hit the headlines in 1996 when its extraordinary size first came to light. Spanning some 14,000 square kilometres, and reaching a depth of nearly 800 metres in parts, it has been shut away from sunlight and the atmosphere for at least 15 million years.
There has been much speculation about the exotic ecosystems that might be found in this unique environment. French, Russian and American scientists looking for evidence of climate change began drilling through the ice sheet above the lake in 1989. But as they were not looking for life forms, the equipment was not sterilised and the samples were never properly stored. The drilling stopped 130 metres from the lake's surface to avoid contaminating it with antifreeze and the drilling fluid, kerosene. At this depth the ice is refrozen lake water, known as accretion ice. Four groups of researchers have found organisms in samples of this ice, suggesting that the lake supports a small but thriving microbial ecosystem. Bu
'"/>
Contact: Claire Bowles
claire.bowles@rbi.co.uk
44-207-331-2751
New Scientist
4-Aug-2004