CU scientists travel the globe to explore life in Antarctica’s cryoconite “gunk”

Above: McMurdo Station courtesy of Gaelen Marsden for Wikimedia Commons

Late last month a group of Colorado scientists embarked on a journey a third of the way around the planet, all to explore gunk-filled holes in vast Antarctic glaciers.

To many of us, the area these scientists travelled to, Antarctica’s McMurdo Dry Valleys, represents absolute desolation. It’s hard to imagine why anyone would chose to spend Thanksgiving so far from home in one of the driest, coldest places on Earth.

According to the team of University of Colorado researchers venturing to the area, the answer exists just beneath the ice.

“The glaciers, despite their cold and lifeless appearance, offer functioning habitats for life,” wrote research associate Dorota Porazinska, along with a team of fellow researchers in a 2004 article published by the university’s Institute of Arctic and Alpine Research – also known as INSTAAR.

Specifically, it’s the holes – known as cryoconite holes in the science world – that function as habitats in such an unlikely region. A picture on the team’s blog shows one of the holes up close: an aqua blue, water-filled depression beneath the surface of one of the glaciers. They contain a bottom layer of sediment and an ice “lid” at the top, and average about 30 centimeters in diameter and 40 centimeters in height, though they can grow significantly as the ice melts.

The microbes exist within the sediment “gunk” layer at the bottom of the depressions, and though they may be tiny, these hardy creatures are able to survive in one of the harshest regions in the world.

That’s what sparked the interest of Steve Schmidt, a professor in CU Boulder’s Department of Ecology and Evolutionary Biology who serves as the project’s principal investigator. While Schmidt didn’t go along for this year’s trip to McMurdo, he has spent decades studying extreme environments, from the Andes of Peru to the Nepalese Himalayas.

The holes are special, Schmidt said, both because they allow life to exist in an extreme climate, and because they serve as individual, closed-off worlds for the microbial communities within.

“The fact that they can be isolated under the ice makes them like isolated islands, so you can study biogeography at a small scale,” he said. “It’s like studying a whole world of different continents just on one glacier.” 

Pacifica Sommers, an ecologist and postdoctoral researcher on the team who studies factors that effect biodiversity called the holes a “Goldilocks system.” 

It’s a rare opportunity to study microbial life so effectively, Sommers said. Most natural settings aren’t closed off like the holes are, so outside factors can contaminate a colony, but transferring the microbes from their natural environment to a controlled lab setting often kills much of the sample. The holes, closed off from outside factors but accessible to scientists, solve this problem.

This is what made the nearly 9,000 mile trip worth it for Sommers, who sees the project as a way to finally test ideas that, until now, she had only been able to theorize about.

Take medicine, for example.

Our bodies are full of microbes, and doctors could improve treatments through a better understanding of biological systems, but so far researchers haven’t found a simple way to study such systems in their natural habitats: patients’ bodies. 

“It’s really hard to drill cores in someone’s butt, but it’s comparatively easier to go down to Antarctica and drill holes in a glacier,” said team member Jack Darcey, a graduate student who plans to use drones to map cryoconite holes throughout the Dry Valleys.  

Darcey was referring to Sommers’ mention of Clostridium Difficile Infections – also known as C. diff infections – as a potential area for crossover research.

The infections are caused when C. diff bacteria overgrow and release toxins that attack the intestinal lining, which can result in abdominal pain and diarrhea that ranges from mildly uncomfortable to life-threatening.  

Antibiotics are a common method of treatment for these infections, but some doctors are turning to fecal transplants as an alternative. The transplants allow doctors to introduce a healthy diversity of bacteria into the patient’s gut, creating a resistance to the C. diff bacterium.   

“You might want to know things like, after a round of antibiotics, or if you get some horrible C. diff infection, how to reestablish a healthy community there,” Sommers said. “You might want to know how many species to introduce — whether it matters what order you introduce them.” 

These are all questions that could potentially be answered by investigating the microbial communities that live within cryoconite holes, Sommers said.

The key word, however, is potentially. The idea that cryoconite holes contain life didn’t gain traction until the late 1990’s, so there isn’t a huge foundation of research on the topic. The team is venturing into somewhat unknown territory not only in terms of their destination, but also in terms of what they’ll be studying.

The microbes dwelling beneath McMurdo’s glaciers still hold many mysteries and endless possibilities, which is all part of the appeal.

“We didn’t even know about most of them until, you know, yesterday, so it’s really really exciting stuff,” Darcey said.   



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