Arctic, Microbiome, What can Arctic microbes tell us about climate change

What can Arctic microbes tell us about climate change?

There’s much that remains mysterious about the vast – and melting – Arctic. With an eye on the region’s long-term environmental sustainability, the Norwegian-led Nansen Legacy project is trying to establish a baseline of knowledge about the Arctic even as climate change alters it. Microbial ecologist Dr. Stefan Thiele’s role: to reveal the microbial communities living in sea ice, sea water and sediments.

Dr. Stefan Thiele tries to live his ethos surrounding sustainability. He eats mostly vegan and limits the amount of plastic he uses in daily life. As a microbial ecologist in the Department of Biological Sciences at the University of Bergen, in Norway, he’s tried to make changes in the lab, where plastic is intrinsic to many kits and instruments, and the ultra-low temperature (ULT) freezers are colder than they need to be. Raising a freezer’s temperature from –80 to –70°C, he says, can reduce a freezer’s energy use by as much energy as an average American household consumes in a year without harming any samples. And though he already has a master’s degree in microbial ecology and a Ph.D., he’s studying for a second master’s degree in sustainability in the little free time he has.

Thiele’s love of nature drives him to explore it. Bergen has 238 rainy days a year, but that doesn’t stop him from hiking the trails winding through the country’s stunning landscape. In this way, Thiele, a native of northern Germany, has adopted one of Norway’s most cherished traditions. “Everybody is on the trail on Sundays,” he says.

That love of nature also drives him to want to protect it. “I always felt we should do something for the world,” he says. “Nature is so beautiful. Why would we destroy it?”

Climate change is the most profound threat to nature. Perhaps no region has seen its impact as much as the Arctic – a region that is still in many ways mysterious. It’s there that Thiele is studying the microbial communities of the Arctic’s sea water, sea ice and sediments to understand how climate change is affecting the smallest organisms of the polar region. His challenge is fourfold: find the organisms, identify them, reveal their behavior and reveal how they change over time. And all this in some of the harshest working conditions in the world.

Microbes are the fundamental core of the ocean’s ecosystem. These microscopic communities effect everything from the ocean’s CO2 to the amount of nutrients up the food chain. Microbial ecologist Dr. Stefan Thiele, heads to the most remote parts of the Arctic, exposing himself to subfreezing temperatures, daunting walks on ice, and the occasional polar bear, to collect very special samples. And he explains why this is all worth the effort.
Not many people have had the honor of being here before, and then on the other hand, if something happens, nature wins. You have no chance.
Dr. Stefan Thiele, Microbial Ecologist, Department of Biological Sciences, University of Bergen

Nansen legacy project overview

Thiele’s work is part of the Nansen Legacy, a six-year research project (2018–2023) aimed at creating a holistic snapshot of the northern Barents Sea and Arctic Basin in this period of rapid climate change so that Arctic scientists of the future have a baseline to compare their own research to. Named after the Norwegian explorer, scientist, diplomat and Nobel Peace Prize winner Fridtjof Nansen, the project’s overarching goal is to enable the long-term sustainability of the Arctic. 

Its microbes are among its least known elements. “I'm looking into sediments to try and see how the warming of the ocean will affect the microbial communities,” Thiele says. “For the same reason, I’m looking into the water column – both the surface waters and deep waters, which are very different. In the surface waters, you have light, and in the depths, it's dark.”

Thiele has made multiple fieldwork voyages aboard the Kronprins Haakon in different seasons to ferret out the differences. “What does the community in the sea look like in summer versus in winter? Or is there a difference between different ice communities in summer and winter? And in the sediment, if the water warms, does that have an effect?”

hero story, arctic, microbiome
Stefan Thiele is a microbial ecologist at the Department of Biological Sciences at the University of Bergen, Norway. In college, Thiele initially studied biology because he wanted to work with animals. “I wanted to be counting lions in the Serengeti or swimming with dolphins,” he admits. Then he took a microbiology class. “I figured out these dudes can do anything. Whatever you can imagine that an organism can do, a microbe is doing it.” He eventually earned his Ph.D. at the Max Planck Institute for Marine Microbiology in Bremen, where the Weser river connects to the North Sea that gave him his love for the marine environment.
The Arctic is two to three fold more prone to climate change due to global warming. 
Dr. Stefan Thiele, Microbial Ecologist, Department of Biological Sciences, University of Bergen

Taking water, ice and sediment samples

The scientists on board are highly collaborative. They collect and process sea, ice and sediment samples for each other from seven field stations across the Barents Sea. “For example, I'm taking samples for colleagues taking viral samples, and they are taking samples for particle nutrition analyses,” Thiele says. “And the samples that I will get in the end are taken in the next lab by the people responsible for DNA sampling.”

QIAGEN toolkits are present throughout, especially the DNeasy PowerWater and PowerSoil (Pro) Kits. 

Their lab is in Longyearbyen, the largest settlement in Svalbard, a nine-island archipelago dominated by glaciers, tundra, snowy mountains and fjords. It’s there that a technician does DNA extraction for the water and ice samples using QIAGEN’s DNeasy PowerWater Sterivex Kit. “You have this plastic tube and the filter system is inside, so you can either crack it open, but that's not really favorable, or you can work in the filter itself. And for this work, the DNeasy PowerWater Sterivex Kit is actually perfect, because it is made to do exactly that.” 

Thiele spends around three weeks collecting and processing samples while traveling on the Kronprins Haakon along with the 30–40 other researchers on board. Time tends to lose much of its meaning. “Once you're on the ship, everything changes in a way. You're going from normal time, with morning and evening, into ship time, which means you basically have three ‘seasons’ – work, sleep or eat,” he says. “Especially when you are out in the Arctic and you have the midnight sun, you're just constantly in daylight. At some point you can only measure your days in meals.” But Thiele takes it all in stride and knows how to stay entertained under these unusual conditions.
I want to find out how the warming of the ocean will affect microbial communities and sediments.
Dr. Stefan Thiele, Microbial Ecologist, Department of Biological Sciences, University of Bergen

Initial findings

“We run into problems with low cell densities,” he says. “Imagine you get an ice core of about 14 centimeters in diameter and then maybe 20 centimeters long. If you melt it, it boils down to about a liter of water, and the cell densities in the ice are not that high. We run into the problem of low DNA yields. So in that case, the DNeasy PowerWater Kit is absolutely perfect for us, because it ensures that we get a lot of DNA out of these samples.”

Each ship voyage yields hundreds of samples – about 50 for sediments and 250 for water and ice.

Thiele now has some initial results from the 2018 and 2019 field seasons. “We already found something very interesting,” he says. “2018 was a year with very little sea ice, while 2019 had a lot of sea ice. If we look at samples from roughly the same time of the year, we have vastly different communities based on their response to algae blooms.”

The algal blooms came earlier in 2018 than in 2019, indicating that “less sea ice will lead to earlier phytoplankton blooms,” he notes. “With these phytoplankton blooms comes carbon cycling and bacterial succession – so we will have a shift in the ecosystem based on how much ice we get. These longer blooms could lead to more carbon going into the system, but we can also imagine that the nutrients are running out, because the bacteria are not fast enough to replenish the nutrients, or there's just too much algae, or the bacteria also use the nutrients. So at some point, the nutrients will run out of the system. And that is a pretty bad thing. The system collapses at some point.” 

arctic, microbiom, hero story, Stefen Thiele
“If I could have a perfect lab, it would not produce any plastic anymore,” he says. “There are a lot of plastic parts that we can get rid of that are not necessary and still get very good results. QIAGEN’s QIAwave is a good first step into this direction, with up to 62% less plastic and up to 58% less cardboard compared to standard QIAGEN purification kits. This is for sure not the end, but this is the way forward. If we follow the 9 Rs of the circular economy consequently, I am sure my dream of a plastic-free lab can become true before I’m old and grumpy. But it needs changes and people need to embrace and back these changes, otherwise there is no evolution. And no evolution in the eyes of a biologist leads to extinction.” 
We want to do metagenomics and metatranscriptomics, so we need both DNA and RNA, and QIAGEN provides the optimal solution for both.

Dr. Stefan Thiele, Microbial Ecologist, Department of Biological Sciences, University of Bergen

The future

While there’s much analysis still to do, Thiele says he may have an opportunity to join another Arctic research ship on a mission to collect more samples. He’d like look at the interactions between eukaryotic hunters and the bacterial prey they feed on. “There are a lot of small predators out there that are eating bacteria. I would like to see how this predation changes the microbial community – which microbes are eaten preferably, and which not? And why not?” 

In the meantime, Thiele’s pursuit of a second master’s degree in sustainability incorporates natural sciences, economics, politics and law. This broader knowledge helps him explain to people who think it’s too late to stop climate change that environmental doom is not inevitable. 

“I believe that the moment we stop thinking about the climate, that we stop caring about it, that's the moment when we've lost. And we have to be very quick to act, because otherwise we are losing the race,” he says. “But I think everybody can do small things. Everything counts. And as long as we do that, there's still hope and a chance for the climate.”

hero story, Stefen Thiele
Research related to climate change can be disheartening when it documents a warming planet’s dire effects, but it motivates Thiele to have hope. “It’s always interesting to see there are still things that we don't understand and still things that could make a major impact. If we find these things, we can put them into the climate models. The climate models will get better, and we will know much more about how the climate is changing—and how we can maybe stop it.”

January 2022