Antarctica's Lake Vida has been sealed beneath the ice for 2,800 years. Its depths have become a concentrated briny brew, freezing cold, and shrouded completely in darkness. And now, researchers have just shown that it has a thriving bacterial ecosystem.
Lake Vida has approximately six times the salt content of ocean water, allowing it to remain liquid despite its constant -13°C temperature. It's also without oxygen, without light, and, in a finishing touch, is slightly acidic with a pH of 6.2. It's sealed under a 50-foot ice cap. In 2002, researchers saw the first successful removal of microbes from the lake, and this paper expounds on the ecosystem found therein.
Perhaps unsurprisingly, it's life quite different to that found in other bodies of water. It's dominated by bacteria in an environment with very high levels of organic carbon, molecular hydrogen, reduced metals, and oxidized nitrogen and sulfur. The researchers believe that the brine reacts with the sediment beneath the lake to create the nitrous oxide and molecular hydrogen, the latter of which could be tapped as an energy source for the microbes. It's helped by the fact that said microbes have an incredibly slow metabolism, prompting the paper to conclude "we contend that metabolism in this encapsulated brine ecosystem may last for a prolonged period, well in excess of its ∼2,800 y of existence."
While this discovery proves that there's yet another crazy environment where life can survive on Earth, it also provides evidence for life on other planets. Super-slow microbes surviving under the ice sheets in previously thought unsurvivable conditions? It's time to do some drilling on Europa!