The ice is 200 meters thick at the point where a research team from the Alfred Wegener Institute (AWI) drilled two holes with hot water. Nevertheless, not far from Neumayer Station III on the Ekström Ice Shelf in the southeastern Weddell Sea, they discovered an astonishing biological diversity on the seabed.
As the team now explains in the journal Current Biology, a total of 77 species came to light. This makes the biodiversity even greater than many samples that were taken in open water, writes the team led by David Barnes, lead author and marine biologist at the British Antarctic Survey.
The remarkable thing about the dark ecosystem under the thick ice is that no plants or algae thrive there, but most of the living things that occur there feed on microalgae. Apparently what is washed up from beyond the edge of the ice shelf is enough for the filter feeders – enough to grow about as fast as other species in the open water. The open sea is three to nine kilometers away from the sampling point.
© Alfred Wegener Institute (detail)
A camera provided a view of the ecosystem below | For at least around 6000 years there has been an ecosystem under the ice that is adapted to the extreme conditions, but nonetheless diverse.
The species discovered under the ice shelf include saber-shaped bryozoa (bryozoa) and tube worms. In order to find out how long the ecosystem had already existed, the experts dated samples of dead animals in the near-surface sediments using the radiocarbon method. The oldest parts were therefore 5800 years old. There seems to be “an oasis of life under the ice shelf for almost 6000 years,” says the head of the research project Gerhard Kuhn from AWI.