The researchers discover, amazed, an unexpected microscopic life: an entire ecosystem that lives in the snow.
Hervé Poirier, editor-in-chief of the scientific magazine Epsiloon, is today interested in the discovery of an entire ecosystem, hidden in the snow. Algae, but also fungi, bacteria adapted to snow and ice.
franceinfo: This discovery is both wonderful and tragic. Explain to us…
Hervé Poirier: It’s wonderful, yes. Biologists have long considered glaciers sterile, a sort of immense freezer. But no. Thanks to genomic sequencing, environmental DNA detection and very high resolution microscopy techniques, they are beginning to be able to explore this environment. And discover a whole people who live in the snow – the power to conquer life is definitely limitless.
Dfungi, bacteria, viruses, and above all, algae. It’s unexpected. Even if these algae had, in fact, been spotted for a long time, because they are responsible for a phenomenon well known to mountain dwellers: “glacier blood”.
Glacier blood?
Aristotle was already talking about it 2500 years ago. He had probably observed it on Mount Olympus: at certain times of the year, in certain places, the snow turns scarlet red. He imagined hairy larvae. Others considered a mushroom. But since the beginning of the 19th century, we have known that these are microscopic algae blooms. Except that they are very difficult to study.
It was only in 2019 that botanists were able to identify the dominant algae of Alpine glaciers: Sanguina. And it is only today that they are discovering how its architecture and metabolism are perfectly adapted to life in the snow.
Around fifteen other algae have since been identified – work is ongoing. Their interactions with other discovered microorganisms are being studied. Who eats who? Who cooperates with whom? Who is in competition with whom? In short, researchers discover, amazed, a whole new ecosystem.
And why is it tragic?
Because barely discovered, these “snow people” are doomed to disappear. As temperatures rise, glaciers are shrinking – and they are warming even faster than the rest of the planet. But the most tragic thing is that by darkening the snow, the algae changes its ability to reflect solar energy, and it melts even faster. It’s a vicious circle.
The researchers, who left for Greenland this summer, returned frightened: they saw expanses of black snow – it is not the Sanguina species that dominates there. Which will accelerate warming even more.
Certain algae, also adapted to other environments, will survive. Others, like Sanguina, are condemned. And the blood of the glaciers that they cause to flow will only accelerate this tragic destiny.