The Unseen Glacier Microorganism Community

Friday - May 5 2023, 00:07 UTC - 1 year ago

A research team from Aarhus University in Denmark uncovered a previously unknown ecosystem in glacial environments, which contains several thousand different species of microorganisms, including a black algae which exponentially increases the melting rate of the ice by 20%. The team is now looking for ways to neutralize the effects of the black algae on the melting rate.

Glaciers contain a large reservoir of microbial life. And these microbial communities in glacial environments can survive on top of the ice, beneath its surface, or in between. Glaciers are an ecosystem on their own. When they melt, their inhabitants also change.

A group of researchers from the Department of Environmental Science at Aarhus University in Denmark have discovered that these glaciers are teeming with life. The team assessed the activity and diversity of microbes living on glacial surfaces in Iceland and Greenland.

There are several thousand different species of microorganisms living under environmental extremes. The study reports that one strategy that enables microbial life to exist and persist in environmental extremes is dormancy, which despite being prevalent among microbial communities in natural settings, has not been directly measured and quantified in glacier surface ecosystems. "A small puddle of melt-water on a glacier can easily have 4,000 different species living in it. They live on bacteria, algae, viruses and microscopic fungi. It’s a whole ecosystem that we never knew existed until recently," said Professor Alexandre Anesio, lead author of the study.

--- Black algae --- .

The vast sheet of ice the team was investigating was covered by black algae formation, which fascinated the team. "When the ice darkens, it becomes more difficult to reflect sunlight. Instead, heat from the sun's rays is absorbed by the ice, which starts to melt. The more the ice melts, the warmer the temperature on Earth. The algae therefore play an important role in global warming," added Anesio in the press release.

The team assessed that the algae are exponentially making the ice melt faster, approximately by 20%, according to their own estimates. And with global warming, additionally, the springtime melting of snow and ice will occur earlier, which means that the black algae will have more time to grow and spread.

"The algae spread a little more every year. When I travel to Greenland, I now see vast areas where the ice is completely dark because of the algae," said Anesio.

The team is now looking into the effects of black algae and finding if the growth rate of algae can be slowed down in some way or another.

Interesting Engineering had earlier reported on how these microorganisms are also found at high elevations, like Mount Everest, which is now acting as a deep freezer for these organisms.

The study was published in the journal Geobiology.

Study abstract: Glacier and ice sheet surfaces host diverse communities of microorganisms whose activity (or inactivity) influences biogeochemical cycles and ice melting. Supraglacial microbes endure various environmental extremes including resource scarcity, frequent temperature fluctuations above and below the freezing point of water, and high UV irradiance during summer followed by months of total darkness during winter. One strategy that enables microbial life to persist through environmental extremes is dormancy, which despite being prevalent among microbial communities in natural settings, has not been directly measured and quantified in glacier surface ecosystems.