Scientists have been forced to rethink the limits of life on Earth after accidentally stumbling upon marine organisms living on a boulder 900 meters (3,000 ft) below an Antarctic ice shelf.
The scientists were attempting to sink a borehole through nearly a kilometer of the Filchner-Ronne ice shelf with the hope of obtaining a sediment core from the seabed. The fact that a boulder prevented them from doing so would have been utterly frustrating had their camera not picked up on something unthinkable: living organisms hanging off the boulder.
“It’s slightly bonkers,” said Dr. Huw Griffiths, a marine biogeographer at the British Antarctic Survey. “Never in a million years would we have thought about looking for this kind of life, because we didn’t think it would be there.”
Although scientists have found some small mobile organisms such as fish, worms, and jellyfish deep beneath ice shelves, never have organisms been found this far below. One of the creatures discovered is stationary filter-feeders, which survive by ingesting food that falls down on them. Considering the total darkness, lack of food, and bone-chilling -2C temperatures, it was quite a surprise for them to be found down there.
In addition, the camera also picked up on at least two types of sponges living on the boulder as well as what appeared to be either tube worms or stalked barnacles.
“This is by far the furthest under an ice shelf that we’ve seen any of these filter-feeding animals,” said Griffiths. “These things are stuck on a rock and only get fed if something comes floating along.”
To be clear, the life-containing boulder is 160 miles from the nearest open water, so any floating food that makes it that far below the ice shelf must come from a long way away. Due to strong currents in the area, the scientists believe that the dead plankton that these filter-feeders ingest is carried anywhere between 370 and 930 miles before reaching them—although there is no way to know for certain.
“It was a real shock to find them there, a really good shock, but we can’t do DNA tests, we can’t work out what they’ve been eating, or how old they are,” said Griffiths. “We don’t even know if they are new species, but they’re definitely living in a place where we wouldn’t expect them to be living.”
Although this story isn’t necessarily a solution, it reminds us once more just how incredible planet Earth is and how much we have yet to discover!
