American scientists believe that Antarctica’s largest and deepest underground lake could contain thousands of different tiny organisms and even fish. Scientists say that the icy darkness of Lake Vostok, which has been cut off from the outside world for 15 million years under 3,700 metres of ice, provides a glimpse of the planet before the Ice Age. Research from Bowling Green State University, Ohio, suggests that the lake harbours plenty of life from bacteria to complex organisms. Not only had most scientists believed Lake Vostok completely inhospitable to life, some thought it might even be sterile After two years of computer analysis of DNA sequences from ice samples, the final results showed that Lake Vostok contains a diverse set of microbes, as well as some multicellular organisms. Over 3,500 DNA sequences were identified in samples of ice ‘as clear as diamonds’ extracted from the ice, of which 95 per cent were associated with types of bacteria. The remaining five per cent of the samples contained hints of more complex organisms called eukaryokes and two of them were linked to one-called organisms called archaea. Dr Scott Rogers, a Bowling Green State University professor of biological sciences and his team found sequences that are similar to types of fungi as well as water fleas, arthropods and a mollusk. Interestingly come of the bacteria are generally found in fish guts, suggesting that there could be fish in the subterranean lake, according to the research published in the PLOS ONE journal. ‘The bounds of what is habitable and what is not are changing,’ said Dr Rogers. Lake Vostok is located 800 miles from the South Pole and 35 million years ago, when the climate was warmer, was thought to have been open to the air and surrounded by forests. The researchers said: ‘At that time, the lake probably contained a complex network of organisms.’ They think that the organisms were sealed in the lake, which is around a quarter of a mile deep, by the thick ice approximately 15 million years ago. They said: ‘While the current conditions are different than earlier in history, the lake seems to have maintained a surprisingly diverse community of organisms. ‘These organisms may have slowly adapted to the changing conditions in Lake Vostok during the past 15 to 35 million years when the lake converted from a terrestrial system to a subglacial system.’ Several of the sequences are similar to organisms that live near deep sea thermal vents, leading researchers to believe that Lake Vostok might contain similar features in its icy depths.
