Strange creatures accidentally discovered under the ice shelves of Antarctica

A recent study in the public diary, far below the ice shelves of Antarctica, has more life than expected Frontiers in marine science.

During an exploratory survey, researchers drilled 900 meters of ice into the Filchner-Ronne ice shelf, located southeast of the Weddell Sea. At a distance of 260 km from the open ocean, under complete darkness and with temperatures of -2.2 ° C, very few animals have ever been 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 boulder on the seabed.

“This discovery is one of those lucky accidents that pushes ideas in another direction and shows us that marine life in Antarctica is incredibly special and amazingly adapted to a frozen world,” says the biogeographer and lead author. Dr. Huw Griffiths to the British Antarctic Survey.

More questions than answers

“Our discovery raises so many questions than answers, such as how they got there? What do they eat? How long have they been there? How common are these boulders covered in life? Are they the same species 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 shelves are the largest unexplored habitat in the Southern Ocean. It covers more than 1.5 square meters of the continental shelf of Antarctica, but only a total area similar to that of a tennis court has been studied through eight previous holes.

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

So it came as a surprise when the team of geologists, who drilled through the ice to collect sediment samples, hit a rock instead of mud from the ocean floor below. They were even more surprised by the video footage, which showed a large boulder covered with strange creatures.

A new Antarctic expedition is needed

This is the first record ever of a hard substrate community (i.e. a boulder) deep beneath an ice shelf and seems to go against all previous theories about what types of life might survive there.

Given the water currents in the region, researchers estimate that this community could reach 1,500 km upstream of the nearest source of photosynthesis. It is also known that other organisms collect nutrients from glacial melts or chemicals from methane filters, but researchers will not know more about these organisms until they have the tools to collect samples of these organisms – a significant challenge in sine.

“To answer our questions we will have to find a way to get closer to these animals and their environment – and that is below 900 meters of ice, 260 km away from the ships in which our laboratories are located,” he 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 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.

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