First identified in 1956 by the Russians and mapped in the 1990s by the British, Vostok covers an area of 15,000 square km, and in places is 800m deep. Researchers believe it has not been open to the atmosphere for many millions of years, and a drilling effort has recently tried to sample its waters.
The new PLoS study examined genetic material - stretches of RNA - isolated from ice that froze on to the ice sheet as it moved above the lake. The supposition was that this content might hint at the type of life present in Vostok.
Thousands of unique matches were identified with sequences already listed in public databases. The vast majority (94%) of these matches were with bacteria, while a smaller group (6%) were with more complex, multi-cellular organisms (eukaryotes). A handful of links were made also to archaea - very primitive, single-celled microbes. A large number of bacterial sequences, reports the team, were from “animal commensals, mutualists and pathogens… including those associated with annelids, sea anemones, brachiopods, tardigrades and fish.”
The team also found matches to types of bacteria that thrive in hot environments, such as around volcanic hydrothermal vents on the sea floor. If such vents existed in Vostok, they could “provide sources of energy and nutrients vital for organisms living in the lake”, the team writes in PloS One.