Far under the ice racks of the Antarctic, there’s more life than expected, finds a new study in the journal Frontiers in Marine Science.
Throughout an exploratory survey, scientists drilled through Nine hundred meters of ice in the Filchner-Ronne Ice rack, located in the southeastern Weddell Sea.
At a distance of 260 kilometers away from the open ocean, under complete darkness and with temperatures of -2.2°C, not many animals have at any point been seen in these conditions.
however, this study is the first to find the existence of stationary animals similar to sponges and possibly a few previously unknown species attached to a stone on the ocean bottom.
Biogeographer and lead author, Dr. Huw Griffiths of the British Antarctic Survey said, “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.”
More questions than answers
“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?”
Floating ice racks represent the greatest unexplored habitat in the Southern Ocean. They cover more than 1.5m sq km of the Antarctic continental rack, however, just a complete area similar in size to a tennis court has been studied through eight prior boreholes.
Current theories on what life could survive under-ice racks propose that all life turns out to be less abundant as you move further away from open water and sunlight. Past studies have discovered some small mobile scavengers and predators, for example, fish, worms, jellyfish, or krill, in these habitats. But filter-feeding organisms that rely upon a supply of food from above were expected to be among the first to disappear further under the ice.
So, it came as an unexpected when the team of geologists, drilling through the ice to collect sediment samples, hit a rock rather than mud at the bottom of the ocean beneath. They were even more surprised by the video footage, which showed a large stone covered in strange creatures.
New Antarctic expedition needed
This is the first-ever record of a hard substrate (ie a stone) local area far below an ice rack and it seems to go against all past theories of what types of life could survive there.
Given the water currents in the region, the researchers calculate that this community may be as much as 1,500km upstream from the closest source of photosynthesis. Other organisms are also known to collect nutrients from glacial melts or chemicals from methane seeps, 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.
“To answer our questions we will have to find a way of getting up close with these animals and their environment—and that’s under 900 meters of ice, 260km away from the ships where our labs are,” continues Griffiths. “This means that as polar scientists, we are going to have to find new and innovative ways to study them and answer all the new questions we have.”
Griffiths and the team also note that with the climate emergency and the collapse of these ice racks, time is running out to study and protect these ecosystems.