Strange creatures found 900 meters under Antarctic ice

Stationary sponge-like animals and potentially unknown species have been found clinging to a rock well below an Antarctic ice shelf.

In an exploratory study, researchers drilled 900 meters of ice on the Filchner-Ronne Ice Shelf, located in the southeastern Weddell Sea. At a distance of 260 km offshore, in total darkness and with temperatures of -2.2 ° C, very few animals were observed in these conditions.

In a statement, lead author and biogeographer Dr Huw Griffiths of the British Antarctic Survey said in a statement: “Our discovery raises many more questions than it answers, for example, how did they get there? What are they eating? How long? How common are these covered rocks in life? Are these the same species we see outside on the ice floes or are they new species? And what would happen to these communities if the sea ice collapsed? “

1.5 million km2, but only one tennis court has been explored

The floating ice shelves represent the largest unexplored habitat in the Southern Ocean. They cover more than 1.5 million square kilometers of the Antarctic continental shelf, but only a total area similar in size to a tennis court has been studied through eight previous holes.

Current theories of what life could survive under the ice shelves suggest that all life becomes less abundant the further away it is from the open ocean and sunlight.

Previous studies have found a few small, mobile predators and scavengers, such as fish, worms, jellyfish or krill, in these habitats. But filter-feeders, which depend on food supplies from above, should 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 samples of sediment, struck a rock instead of mud on the ocean floor. They were even more surprised by the video footage, which showed a large boulder covered in strange creatures.

This is the first record of a hard-substrate community (i.e. a boulder) at the bottom of an ice shelf and it seems to run counter to all previous theories about them. types of life that could survive there.

Considering the water currents in the area, the researchers estimate that this community may be up to 1,500 kilometers from the nearest photosynthetic source. Other organisms are also known to collect nutrients from melting glaciers or chemicals from methane seeps, but researchers won’t know more about these organisms until they have the tools to collect them. samples of these organisms – a tall order in itself.

“To answer our questions, we’ll need to find a way to get closer to these animals and their environment, and that’s under 900 meters of ice, 260 kilometers from the ships where our labs are,” Griffiths continues.

“This means that as polar scientists we will have to find new and innovative ways to study them and answer any new questions we ask ourselves.”

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.