Deep beneath Antarctica, locked under an ice shelf some 260 kilometers (161 miles) away from the open ocean, strange life forms have been found.
The creatures were discovered by the British Antarctic Survey during an attempt to gather a sediment core sample from under the ice shelf in the Filchner-Ronne Ice Shelf. While tunneling around 900 meters (2952 feet) into the ice shelf, their drill suddenly hit a boulder. Even more unexpectedly, a camera attached to the drill revealed that a community of creatures were latched onto the rock (picture below).
The community of marine organisms are stationary animals similar to sponges but potentially belong to several different unknown species. As the researchers note in their new study, published in the journal Frontiers in Marine Science, the discovery breaks many of the rules on what we know about life on Earth.
Previous expeditions have found some small mobile scavengers and predators, such as fish, worms, and krill, in similar Antarctic habitats to this. However, this new discovery is especially surprising since the animals are sessile, meaning they are fixed and not mobile. Such stationary creatures are typically filter feeders that rely on food to drift past from above.
Furthermore, they are extremely far from open water and sunlight, living under complete darkness with temperatures of -2.2 °C. This new study estimates this community is up to 1,500 kilometers (932 miles) upstream from the closest source of photosynthesis, raising questions about how they obtain energy and nutrients.
"Our discovery raises so many more questions than it answers, such as how did they get there? What are they eating? How long have they been there? How common are these boulders covered in life? Are these the same species as we see outside the ice shelf or are they new species? And what would happen to these communities if the ice shelf collapsed?,” asks Dr Huw Griffiths, biogeographer and lead author of British Antarctic Survey, in a statement.
“This discovery is one of those fortunate accidents that pushes ideas in a different direction and shows us that Antarctic marine life is incredibly special and amazingly adapted to a frozen world,” Dr Griffiths adds.
It’s possible that the organisms obtain their energy through other means, such as from glacial melts or via chemotrophic processes from methane seeps. To find out, the team will need to collect samples of these organisms, which is no small feat considering their desperately remote location.
Ice shelves cover roughly a third of the Antarctic’s 5 million square kilometers of continental shelf, much of which has remained totally unexplored. The discovery could indicate that life beneath the ice shelf is more common than previously appreciated, just as other recent studies have hinted. In 2019, scientists found colonies of bacteria and other more complex life in Lake Mercer, a glacial lake found beneath the West Antarctic ice sheet.