A world of unusual forms of life under the ice of Antarctica . A team of scientists stumbled upon something surprising when they decided to drill a 900-meter-long hole in an Antarctic ice shelf in order to collect sediment samples from the ocean floor: a rock covered with hitherto unknown animals on the seafloor. .
They had set up camp on the Filchner-Ronne Ice Shelf, a large body of floating ice in the southeastern Weddell Sea. Once the entire hole was completed, they lowered a camera with their sediment corer to observe the seabed more than 300 meters below the bottom of the platform. And there, in this dark place and with temperatures below zero, they found a rock that is home to several species that we have probably never seen.
The community of marine organisms are stationary animals similar to sponges but potentially belong to several different unknown species.
They are also very far from open water and sunlight. They live in complete darkness with temperatures of -2.2 ° C. How do they get their energy and nutrients? Perhaps the melting of glaciers? Animals are sessile, which means that they are fixed and not mobile, that is, they depend on food that passes from above for their survival.
“This discovery is one of those lucky accidents that pushes ideas in a different direction and shows us that Antarctic marine life is incredibly special and surprisingly adapted to an icy world,” British Antarctic Survey biogeographer Huw Griffiths commented in the study that collects the journal Frontiers in Marine Science.
This part of the world is one of the last most unexplored regions on the planet, as floating ice shelves have made it impossible to study the depths of the ocean. Hardly an area the size of a tennis court has been surveyed, thanks to eight pits drilled into the ice, so this iron fortress of ice is still a great mystery to us. The extreme climate of the area only complicates efforts due to its poor accessibility.
“Our discovery raises many more questions than it answers, for example, how did they get there? What do they eat? How long have they been there? How common are these life-covered boulders? Are these the ones? The same species that we see outside the ice shelf or are they new species? And what would happen to these communities if the ice shelf collapsed? ” scientists wonder.
Current theories clearly state that life becomes increasingly unlikely the lower we go underwater and the further away from open water.
How will we answer all these questions?
“To answer our questions, we will have to find a way to get closer to these animals and their environment, and that is under 900 meters of ice, 260 km from the ships where our laboratories are,” adds Griffiths . “This means that, as polar scientists, we will have to find new and innovative ways to study them and answer all the new questions that we have.”
Will life be more frequent than we thought?
Referencia: Huw J. Griffiths et al, Breaking All the Rules: The First Recorded Hard Substrate Sessile Benthic Community Far Beneath an Antarctic Ice Shelf, Frontiers in Marine Science (2021). DOI: 10.3389/fmars.2021.642040
