Strange living forms have been discovered deep beneath Antarctica, trapped behind an ice sheet some 260 kilometers (161 miles) from the open ocean.
During an effort to collect a sediment core sample from beneath the ice shelf on the Filchner-Ronne Ice Shelf, the British Antarctic Survey spotted the critters. Their drill hit a rock while drilling roughly 900 meters (2952 ft) beneath the ice shelf. Surprisingly, a camera linked to the drill revealed that a population of organisms had taken up residence on the rock (picture below).
The community of marine creatures is made up of stationary animals that look like sponges but might be from numerous distinct species. The revelation, as the researchers point out in their recent article published in the journal Frontiers in Marine Science, defies many of our preconceived notions about life on Earth.
Small mobile scavengers and predators, including as fish, worms, and krill, have been discovered in comparable Antarctic settings by previous missions. This new discovery is even the more startling because the creatures are sessile, which means they are not mobile. Filter feeders, which rely on food drifting down from above, are typical of such sedentary organisms.
Furthermore, they live in full darkness with temperatures of -2.2 °C, far away from open water and sunshine. This population is estimated to be up to 1,500 kilometers (932 miles) upstream from the nearest source of photosynthesis, raising issues about how they receive energy and nutrients, according to this new study.
“Our finding raises many more questions than it answers, for example, how did they get there?” What are they munching on? I’m curious as to how long they’ve been there. In real life, how frequently are these boulders covered? Are these the same species as those found outside of the ice shelf, or are they new? In a statement, Dr Huw Griffiths, biogeographer and principal author of the British Antarctic Survey, wonders, “And what would happen to these populations if the ice shelf collapsed?”
Dr. Griffiths adds, “This discovery is one of those happy accidents that pushes thoughts in a different path and reminds us that Antarctic marine life is extraordinarily special and superbly suited to a frozen planet.”
It’s likely that the creatures get their energy from other sources, such as glacial meltwater or methane seep chemotrophic activities. To find out, the researchers will have to gather samples of these species, which will be no easy task given their extreme remoteness.
Ice shelves encompass about a third of the Antarctic continent’s 5 million square kilometers of continental shelf, much of which is yet undiscovered. As other recent research have shown, the discovery might imply that life beneath the ice shelf is more abundant than previously thought. In Lake Mercer, a glacial lake beneath the West Antarctic ice sheet, scientists discovered bacterium colonies and other more complex life in 2019.