Researchers exploring the sea floor in Antarctica have discovered a huge colony of ice fish “about a third the size of London”.
The surprising discovery of about 60 million active nests was made by a team of biologists during routine data collection in the southern Weddell Sea in Antarctica.
Prior to this discovery, the largest colony found contained only 60 nests.
“We expected to see a natural sea floor in Antarctica [mas] “During the first four hours of diving, we saw nothing but fish nests,” says Otton Purser, of the Alfred Wegener Institute for Polar and Marine Research in Germany, and lead author of the study published in Current Biology.
The ecosystem was found by chance using a photo and video recording system and measurements of deep water habitats.
The researchers were initially interested in the area because of a process called bottoming, in which winds and currents bring cold water to the surface, causing the water to warm by two degrees Celsius than the surrounding area.
This colony of ice fish is the largest found so far, extending 240 kilometers below sea level.
Colony size indicates that the Weddell Sea ecosystem is affected by these nests.
“It’s very likely that seals were feeding on these fish nests,” Purser says.
Purser says the discovery showed that there are still significant gaps in understanding how deep-sea ecosystems function.
“Deep seas are not deserts, they are really full of life,” he says, adding that “the fact that there are ecosystems so large that we didn’t know about them shows how, probably, they remain to be discovered.”
The ecosystem will be monitored over the next two years to try to determine how it functions and how it interacts with other ecosystems.
The researchers plan to return to the area in April 2022, to survey the surrounding waters and see if the fish are breeding again in the same nests.
