TUESDAY, JUNE 8TH, 2021
Atop the French Alps, thousands of feet above sea level, the normally white snow sometimes appears stained with blotches of dark red blood, some of which extend for miles.
But no, these aren't the sites of violent mountaintop massacres — the spooky red stains, known as "glacier blood," actually come from microalgae that live in the snow, and scientists recently trekked into the Alps to study these mysterious organisms.
The expedition is part of the AlpAlga project, an effort to study microalgae living in the mountains, 3,280 to 9,842 feet (1,000 to 3,000 meters) above sea level. Much like the microalgae that inhabit oceans, lakes and rivers, snow-borne microalgae help form the base of the food web of a mountainous ecosystem and likely react to pollution and climate change in a similar fashion, said Eric Maréchal, a coordinator of the AlpAlga consortium and a director of the Laboratory of Cellular and Plant Physiology, a research facility in Grenoble, France.
In general, microalgae cells measure only a few ten-thousandths of an inch (thousandths of a millimeter) across, and they can exist as either isolated single-cell organisms or colonies. They produce sugars through photosynthesis, "and all the ecosystem eats that, directly and indirectly," whether the algae grows in the liquid ocean or in compacted snow in the mountains.