But because researchers have not been able to collect specimens, they still cannot say what these sponges and other creatures might eat. Some sponges filter organic waste from the water, while others are carnivorous, spending time with small animals. “That it would be a kind of title of the year, “says Christopher Mah, a marine biologist at the Smithsonian who was not involved in the research. “Deadly sponges, living in the dark, cold depressions of Antarctica, where no life can survive. ”
And Griffiths and his team still can’t tell if mobile creatures like fish and shellfish live around the rock – the camera didn’t see any – so it’s unclear if the sessile animals are facing any kind of predation. “Do they all eat the same source of food?” Griffiths asks. “Or do some of them get nutrients from each other? Or are there more mobile animals that somehow provide food for this community? “All these are questions that only another expedition can answer.
It seems that the sedimentation around the rock is not very heavy, which means that the animals are not in danger of being buried. “It’s kind of like Goldilocks,” says Griffiths from the seemingly fortuitous location of the rock, “where only enough food comes in and there’s nothing he wants to eat – as far as we know – and he’s not buried by too many.” sediments. ”(In the sediment surrounding the rock, the researchers also observed ripples that are usually formed by currents, thus reinforcing the theory that food is transported here from afar).
It is also not clear how these stationary animals came to be in the first place. “Was it something very local, where they kind of jumped from the local boulder to the local boulder?” Griffiths asks. Alternatively, perhaps their parents lived on a rock hundreds of miles away – where the ice shelf ends and the more typical marine ecosystems begin – and released their sperm and eggs to travel in currents.
Because Griffiths and his colleagues do not have specimens, they cannot say how old these animals are. Antarctic sponges have been known to live for thousands of years, so it is possible that this is a truly ancient ecosystem. The rock may have been sown alive a long time ago, but the currents have refreshed it with extra life over the millennia.
Also, researchers cannot say whether this rock is an aberration or whether such ecosystems are actually common under ice. Maybe geologists weren’t very lucky when they threw their camera on the rock – maybe these animal communities are a common feature of the seabed under Antarctic ice shelves. There would certainly be plenty of room for such ecosystems: these floating ice shelves stretch over 560,000 square miles. However, through previous drilling, scientists have only explored an area below them equal to the size of a tennis court. So it may be that they are there in large numbers, and I just haven’t found them yet.
And we may run out of time to do so. This rock can be trapped under half a kilometer of ice, but ice is increasingly endangered on a warming planet. “There is a potential for some of these large ice shelves to collapse in the future,” says Griffiths, “and we could lose a unique ecosystem.”
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