In Popsci, Francie Diep reports on a new study of Lake Vostok – Antartica’s largest sealed lake:
For this study, the Ohio biologists examined ice gathered from just underneath Lake Vostok’s glacier, at the lake’s southern edges. Scientists think such ice, called accretion ice, represents water from the surface of the lake that froze to the glacier. Getting accretion ice isn’t as difficult as drilling through the glacier in search of deeper liquid water, so it’s actually been available for study since the 1990s. However, biologists didn’t previously have access to the genetic analysis techniques they do now. The techniques weren’t invented yet. After comparing the genetic material they found in Lake Vostok to a database of the known microbes on Earth, the biologists found a remarkable variety of critters. There were organisms known for living in salt water, fresh water, super-hot water and even in the guts and other body parts of tube worms, fish and other animals. There were low amounts of genetic material that appeared to come from animals such as a microscopic crustacean, a marine bivalve and a small sea anemone. Vostok is a freshwater lake, but it may have originally been connected with the ocean and still contain layers of salt water, they said. The thermophilic organisms may mean that there’s some hydrothermal activity inside Lake Vostok, whose bottom is a rift valley that could well be thermally active. Volcanic vents and other activity may add energy and nutrients into the lake that can’t come in from the surface.