Strange creatures discovered accidentally under the Antarctic ice shelves

Far below the Antarctic ice shelves, there is more life than expected, finds a recent study in the journal Frontiers in marine science.

During exploratory research, the researchers drilled 900 meters of ice on the Filchner-Ronne Ice Shelf, located in the southeast of the Weddell Sea. At a distance of 260km from the open ocean, under complete darkness and with temperatures of -2.2 ° C, very few animals were observed in these conditions.

But this study is the first to discover the existence of stationary animals – similar to sponges and potentially several previously unknown species – attached to a rock at the bottom of the sea.

“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 incredibly adapted to a frozen world,” says biogeographer and lead author, Dr. Huw Griffiths of British Antarctic Survey.

More questions than answers

“Our discovery raises many more questions than answers, like how did they get there? What are they eating? How long have they been there? How common are these stones covered in life? Are they 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? “

Floating ice platforms represent the largest unexplored habitat in the Southern Ocean. They cover more than 1.5 km² of the continental shelf of Antarctica, but only a total area similar in size to a tennis court has been studied through eight previous wells.

Current theories about how life could survive under the ice shelves suggest that all life becomes less abundant as you move away from open water and sunlight. Previous studies have found some small scavengers and predators, such as fish, worms, jellyfish or krill, in these habitats. But the filter-feeding organisms – which depend on a supply of food from above – were expected to be among the first to disappear further under the ice.

So it was a surprise when the team of geologists, drilling through the ice to collect sediment samples, hit a rock instead of mud on the ocean floor. They were even more surprised by the video, which showed a large stone covered by strange creatures.

New Antarctic Expedition Required

This is the first record of a hard-substrate community (that is, a rock) in the depths of an ice shelf and seems to go against all previous theories about what types of life could survive there.

Given the water currents in the region, the researchers estimate that this community may be up to 1,500 km upstream from the nearest source of photosynthesis. Other organisms are also known to collect nutrients from glacial melts or chemicals from methane infiltrations, but researchers will not 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 to get closer to these animals and their environment – and that is less than 900 meters of ice, 260 km away from the ships where our labs are,” continues 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.”

Griffiths and the team also note that, with the climate crisis and the collapse of these ice shelves, time is running out to study and protect these ecosystems.