Khaberni - Scientists from the University of Copenhagen in Denmark have discovered an impossible phenomenon beneath the sea ice in the Arctic, where they found microscopic organisms living under conditions previously thought to be unsuitable for life.
These microscopic bacteria live under the frozen surface of the Arctic Ocean, surviving by breaking down organic materials dissolved in the cold waters. What is even more astonishing is that they need to convert nitrogen into usable forms, despite this gas being essentially rare in that region.
The scientific team says: "We have discovered an important phenomenon beneath the sea ice in the Arctic that was previously thought to be impossible." These bacteria, known as "non-cyanobacterial diazotrophs" (or briefly NCDs), do not perform photosynthesis but rely on converting atmospheric nitrogen into nourishing forms such as ammonium.
By collecting water samples from 13 different locations in the Arctic, the scientists found surprisingly high rates of nitrogen fixation, especially at the ice edge where melting occurs actively.
Dr. Lisa von Freizen explains: "Until now, it was believed that nitrogen fixation could not occur under sea ice, and we were wrong."
It appears that there is an unexpected cooperation between these bacteria and algae, where the bacteria release "fixed" nitrogen that helps the algae grow. However, this cooperation may carry risks, as excessive algae growth can lead to a toxic "algae bloom" that threatens fish and marine mammals.
The research suggests that the productive potential of algae in the Arctic may have been previously underestimated. With temperatures rising at rates up to four times the global average and the ice cover receding, it seems that climate change is responsible for these unexpected environmental shifts.
This study presents the first evidence of nitrogen fixation occurring under sea ice in the central Arctic, opening a new chapter in our understanding of this sensitive ecosystem.
