Drilling down half a mile beneath the Antarctic ice and discovering mysterious signs of life sounds like the setup to a horror film. Instead, it’s the latest finding from the British Antarctic Survey, which is reporting the first time stationary animals have been identified in the deeply inhospitable frozen environment.
The general consensus is that, as you go further down, temperature dropping and pressure increasing, animal life is gradually squeezed out of the equation. In the Filchner-Ronne Ice Shelf, situated on the south eastern Weddell Sea, then, the expectations for animals are low.
It’s about 160 miles from open ocean, and when the survey team drilled down 900 meters – or almost 3,000 feet – hopes weren’t exactly high for living creatures in the -2.2 degrees Centigrade (28F) conditions. Instead, according to a new study published in Frontiers in Marine Science, they found what could be entirely new species living there. Clinging to a mysterious rock, the so-called hard substrate community is the first to be recorded.
What makes it particularly surprising, the group say in a press release, is that “it appears to go against all previous theories of what types of life could survive” in those conditions. The video showed filter feeding organisms, which can only survive if they have a source of food that replenishes via photosynthesis. The closest source of that, however, is potentially almost a thousand miles away.
“Other organisms are also known to collect nutrients from glacial melts or chemicals from methane seeps,” the group explains, “but the researchers won’t know more about these organisms until they have the tools to collect samples of these organisms–a significant challenge in itself.”
There’s a reason, after all, that the depths of the ice shelves are so mysterious. This particular location is around 160 miles from where the British Antarctic Survey’s base ships are, and that’s before you consider reaching the depths at which they’re apparently living. Floating ice shelves in general cover a vast area – the seafloor underneath is equivalent to around a third of the Antarctic’s continental shelf – but are relatively unexplored, with just eight prior boreholes drilled.
The community is made up of what’s known is sessile organisms, such as sponges. They consume plankton that drifts down from above, and can build up into high levels of biomass in continental shelf areas. However areas beneath floating ice shelves are far less friendly for such growths, given they’re predominantly cut off from daylight and thus the flourishing photosynthesis which the plankton make use of.
For now, there are still more questions than the scientists have answers. It’s unclear how long the sessile community has been there, or how widespread it is. Even the species that make it up are uncertain – “it is impossible to tell if they are glass sponges, demosponges, or calcareous” the study concludes – and whether they gathered there or evolved in place. What seems most clear, however, is that climate change and its impact on ice shelves could have a huge, and detrimental, effect on these previously unknown animals, which scientists say could help explain how the first complex organisms on Earth actually evolved.