Hidden life found beneath Antarctic ice shelf
Down in Antarctica, researchers have made the rather surprising and accidental discovery of life in a place we thought it couldn’t exist. They've reported seeing animals resembling sponges, quite happily ‘chilling’ on a boulder on the sea floor, under a massive sheet of ice. Huw Griffiths from the British Antarctic Survey told Katie Haylor how it happened...
Huw - This was a total accident. The researchers who discovered this weren't even biologists, they were geologists. And they were drilling through this huge floating ice shelf to try and get at some mud from underneath. There's sort of 900 metres thick of ice and then 500 metres of seawater, and they wanted to get the mud that would be able to tell them the history of the ice shelf. Unfortunately, after doing all that work, they hit a rock instead of mud at the bottom! And luckily for us, they'd attached a video camera and they were able to spot that there was some strange life growing on it. So they brought it back to Cambridge - the video that is - and showed us.
Katie - Blimey, what are these creatures? What can you glean from the footage? What are we talking about?
Huw - We're looking at animals that are attached to the rock. There's at least four types of them, from their body shapes. And two of them we definitely think are sponges. One is kind of like a wine glass-shaped with a very long stem, and the others look like classic sponges, almost vase-shaped attached directly to the rock. Beyond that there's another couple of types of animals: one has almost a moss-type appearance to it, and we only see that when the camera actually bashes into the rock.
Katie - Isn't it quite surprising to find a rock with life in it on the seafloor?
Huw - It wouldn't be surprising to find a rock, because that can drop off the bottom of the ice shelf; this ice used to be on land that has been pushed off. This rock was 260 kilometres back from any daylight. So any animals that we normally find underneath an ice shelf are ones that can run around and go to where the food is, because obviously the further you are from daylight in the ocean, the less food you're going to get. We expected to lose filter feeding animals like these a lot further out towards the daylight.
Katie - How are they actually surviving on this rock under this ice?
Huw - We think they're getting food with some currents that circulate under the ice shelf from the open water. But unfortunately for them, the food has to go the long way, because they're currently on the outflow of the current system, not the inflow. That means the food that comes in is coming from almost 600-1000 kilometres away. So it's basically like being at the end of the line on a night bus or something, where everyone else has got off; the food is down to the kind of dregs by the time it gets to these sponges.
Katie - Oh no, poor sponges! You mentioned that you took the footage back to Cambridge, but do you think you could actually get one up to the surface to look at it more closely? Is that practical?
Huw - It's not with our current technology that we have. So we're talking about looking for life on frozen moons, and things around the universe; those kinds of technologies are probably what we're going to have to employ here, because we've got two options: we send the device from 260 kilometres away on its own under the ice, and hope that it manages to do a job without any human interference, or we put something down one of these boreholes. But these boreholes are only about a foot across, and most of our proper underwater robotics are much bigger than that. And if we try smaller ones in the Antarctic, they tend to freeze up and break within a few minutes because the water's minus two degrees. So it's about miniaturising our tech and making it more rugged, so that we can put things down that will collect a tissue sample without destroying the whole thing. Because we don't know how special this environment is; we can't destroy it by trying to pull the whole rock up, for example.
Katie - Do you have any idea if this is a one off, or if you stumbled upon something that might be a bit more prevalent?
Huw - We're talking about an area that covers one third of the Antarctic continental shelf, which is about 1.6 million square kilometres. So that's bigger than a country like South Africa. If we found one by accident, then I'm guessing there are a lot more boulders under there, and there's probably a lot more life attached to those boulders. But what sort of life that is... given we didn't expect to find these, it could be anything! Which is amazing, But also shows us there's a huge habitat that we really know nothing about.
Katie - This sounds like a pretty extreme environment to me. Do you think these sorts of life forms would be relatively unique?
Huw - Well, when we work in Antarctica anyway, if we work in sort of normal depths, about 10 to 20% of what we find is new to science. And if we go into the deep sea, it goes up to: about 80 or 90% of what we find is new to science. So if we're going to an even more extreme habitat than the deep sea, which is what this habitat is, then the likelihood is, you have to be pretty specially adapted to survive on this kind of extremely low calorie diet. And given that two ice shelves have collapsed in my lifetime, that also makes them incredibly vulnerable to things like climate change, because we may lose the entire habitat before we've even found out what lives there.