The tiny ice inhabitants darken the glacier’s surface, which can accelerate its melting.
Glaciers are massive bodies of white ice that reflect a significant amount of sunlight. However, in areas where the snow has melted and the bare ice is exposed, dark patches often appear.
These dark areas are caused by microscopic algae that grow directly on the ice. By darkening the surface, these algae reduce the glacier’s ability to reflect sunlight, leading to increased absorption of heat. This, in turn, causes the ice to warm and melt more quickly.
Mysterious algae growth
Little is known about how the tiny algae obtain the nutrients they need to survive in the harsh environment of glacial ice. To explore this question, a research team led by Laura Halbach, Katharina Kitzinger, and Alexandre Anesio from the Max Planck Institute for Marine Microbiology in Bremen, Germany, along with colleagues from Aarhus University in Denmark, conducted a study on the Greenland Ice Sheet.
They discovered that the algae on the glacier ice are true champions of nutrient uptake.
“I wanted to understand how such algal blooms can develop in Greenland,” explains lead author Laura Halbach from the Max Planck Institute for Marine Microbiology.
Using new methods, Halbach was the first researcher ever to measure how the algae absorb and store nutrients.
“The algae can grow and colonize the ice despite the scarcity of nutrients,” says Halbach.
“On the west coast of Greenland, around a tenth of the ice melt is already caused by these microscopic inhabitants. In some cases, they darken the glacier surface so much that is even visible on satellite images. In view of the fact that the climate is getting warmer and ever more snow-free areas and thus more potential habitat for the algae appears on the Greenland Ice Sheet, the algae’s ability to efficiently absorb and store nutrients is particularly significant.”
Efficient nutrient uptake of global importance
The Greenland Ice Sheet plays an important role in our climate. Its melting contributes significantly to global sea level rise, as it releases large quantities of fresh water into the oceans. Due to global warming, the snow disappears from ever more glacier areas and the ice is exposed.
This creates new areas that can be colonized by ice algae, which in turn accelerates the melting – a cycle that urgently needs to be understood in more detail.
Here, the present study takes us a big step forward: “Until now, there have been no measurements of how the ice algae supply themselves with nutrients,” says Halbach.
“We are now closing this gap with a particularly precise method that allows us to measure the nutrient uptake and storage of individual cells. Our results show that the algae can grow rapidly even though there are hardly any nutrients available on the spot. Instead, they can efficiently take up inorganic nitrogen and are good at storing phosphorus.”
If these ice algae are not otherwise decimated, for example by parasitic fungi or a lack of trace elements, there would be little to stop their growth. They could grow on exposed ice surfaces and thus intensify the ice melt – a potential positive feedback with global warming.
The findings of the researchers led by Laura Halbach are not only fascinating, but also important. They will help to better predict the contribution of the dark pigmented algae to the melting of the Greenland Ice Sheet. Calculations of the annual ice melt are incorporated into today’s climate models. The new findings could be used to improve the representation of the algae in models predicting the ice melt, and thus better incorporate its effect on the global climate.
Reference: “Single-cell imaging reveals efficient nutrient uptake and growth of microalgae darkening the Greenland Ice Sheet” by Laura Halbach, Katharina Kitzinger, Martin Hansen, Sten Littmann, Liane G. Benning, James A. Bradley, Martin J. Whitehouse, Malin Olofsson, Rey Mourot, Martyn Tranter, Marcel M. M. Kuypers, Lea Ellegaard-Jensen and Alexandre M. Anesio, 19 February 2025, Nature Communications.
DOI: 10.1038/s41467-025-56664-6
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1 Comment
And this algae is caused by my car burning gas right? I mean it HAS to be since we’ve been yelled at and screamed at and shamed and told that it’s OUR fault the glaciers are all melting and that we’re ALL GOING TO DIE!!!!.
So… if an algae is responsible for even a tiny bit of that melting then the algae MUST be caused by my car.
And what is with the refeence to … Global Warming?? I thought that had been rebranded as Climate “Change” since there hasn’t actually been much warming despite all the dire predictions of doom. And Dr. Mann’s Hockey Stick turned out to be pure bunkum and fake data.
You folks have so corrupted Science with Ideology and Political Agendas that no one really believes much of anything you say anymore.