Diversity in action

By Rey Mourot 

How going to the Greenland Ice Sheet to study glacier microbial communities, their impact, and their diversity … teaches us quite something about our own! 

“Do we have everything ?”

The kitchen is full of stuff as I’m making sandwiches for the day on the ice sheet. Gluten-free bread and lactose-free spread cheese for Helen; this amazing vegan-feta thing for Katie, cheese and all the crappy food that fuels my motivation daily … thanks god Liane eats pretty much everything. Sandwiches packed, and here we go. Helicopter, ice sheet.

Helen, our GFZ postdoc. Fascinated by eukaryotic algae, she’s the “culturing” part of our team – although, as she says, she’s not able to keep a pet plant alive 😊

While they dig snow pits, the American Katie gently pokes on Helen’s British/Scottish accent and they try to imitate each other. I’m coring in silence, enjoying that my French accent is not brought up in the conversation. Liane is a few meters upwards from us, collecting air and snow samples; as a “European citizen” as she likes to say, her accent is from everywhere and nowhere at the same time.

  

Liane, GFZ Professor and the PI on this trip. Here to supervise, keep us alive and sample aerosols; although not necessarily in that order. Picture by Katie Sipes.

And as it should be, there’s no fieldwork in Greenland without Greenlanders – and our helicopter pilot Pilu, from Sermeq Helicopters, who has seen it all and way too cool to describe, completes our joyful team of small human-ants on the ice. In-between the jokes, our little fieldwork is going smoothly.

 

A view of our office on June 4th. 

Although this year we are only dashing in and out of our field site, I remember our long camping fieldworks of the two past years as a founding experience when it comes to learning from others and about ourselves.

On the ice sheet, isolated from the world and our dear and otherwise ever-present web connections, we quickly get to know each other by sharing common scientific interests and goals, but also by building an everyday life together – cooking, cleaning, doing the dishes, securing the camp, informing one another about the new crevasses that can be spotted around, how to flush the most correctly our natural waste. Camp mood and closeness is important both for the productivity of our sampling and our survival; and we all quickly learn the needs and quirks of each of us that need to be fulfilled to keep each member of the team happy.

Our DP 2021 field camp after the mist suddenly fell on it … speaking about extreme environments.  

This one works in the evening but will be late at breakfast; this one’s mental health depends on a constant supply of hot chocolate, this one needs to snack regularly or their mood will suffer, this one need more access to the communications to the mainland at the moment, this one will take afternoon naps, this one gets cold faster. Although we are all self-preserving, it actually becomes part of the routine to check on each-other, especially in an extreme environment. After all, several studies indicates that mutualistic groups have a higher chance of survival than groups composed of individualistic members.

Katie, postdoc in bioinformatics, the Aarhus part of our team, swimming among the icebergs in the harbor – among many other crazy things she does daily.

We easily adapt to our important diversity by giving our members maybe not the exact same things; but rather, what they need so the team functions at best. I sometimes wonder why this kind of diversity just functions so well for us, but the fieldwork world is still barely able to make gears that are safe and practical to use for everybody, pants half the population wouldn’t need to put down to their knee by a shitty weather to pee, and just, in general, space for all that do not correspond to the dominant idea of the explorer. 

In this bright month of June, far away from those considerations, our little four-people team is working to perfection; flowing smoothly between our differences of tastes, cultures and rhythms, as we learn to know each other’s qualities and quirks.

And, of course, the real stars of our fieldworks … these aggregates of cells and minerals trapped under the snow layer since September, and that we managed to reach to study them! 

 

 

Introduction to the Mineral-Microbe-Interface team

The Mineral-Microbe-Interface (or "MMI") team, made up of seven early career scientists and led by Liane G. Benning, are based at the German Research Centre for Geosciences, GFZ, in Potsdam, Germany. Their research goal this summer is to assess the compositions, fluxes, rates and interactions between of all types of light absorbing particulates (microbes, minerals, black carbon). The team will focus on assessing variations in carbon and other crucial element cycles with a particular focus on the role of pigmented snow and ice algae. By combining molecular microbiological / organic geochemical and mineralogical sampling and analyses our quest is to elucidate how microbe-mineral-interface reactions are affected by delivery/on-ice processing/retention or downstream removal during melting and during overwintering.

Chris Trivedi, PhD (Postdoc)

Chris' research interests include using sequencing technologies and bioinformatics to better understand the role that microorganisms play in glacial melt dynamics. In particular, for fieldwork in 2021, he will focus on potential seasonal changes in snow/ice algae via changes in pigment and EPS production using metagenomic and metatranscriptomic sequencing, paired with metabolomics. Additionally, he is interested in the role bacteria play in conjunction with the algae and what mutualistic relationships may exist between the two domains.
 
Stefanie Lutz, PhD (Postdoc)

 
Steffi's research focuses on the microbial diversity and functions of glacial surfaces. In particular, she is interested in the role of cryophilic algae in these ecosystems. Her goal is to get a better understanding of their distribution, as well as their genetic and metabolic inventory that allows them to thrive in these extreme environments. This will be accomplished by using various 'omics' techniques and bioinformatics. 
 
Elisa Katharina Peter (PhD student)

 
Elisa is interested in the metabolic fingerprint and adaptation of glacial microorganisms, and the factors allowing them to survive and thrive in such extreme environments. Her focus is on determining metabolic triggers and controls of pigment formation in the snow and ice algae that cause darkening and increased melting  of the Greenland Ice Sheet. Using a combination of various high resolution mass spectrometric techniques, Elisa targets the variations in primary and secondary algal metabolites and how these change as a function of diurnal and seasonal bloom developments.
 
Rey Mourot (PhD Student)

 
"How do micro-organisms survive in extreme environments?" is one of the questions motivating Rey's scientific interest. As part of the DEEP PURPLE project, their research focuses on glacial microbial communities to better understand how mutualistic interactions could help organisms to survive through the arctic winter, when temperatures, light conditions and the lack of liquid water represent a major stress. With this focus, they are using computed tomography and microscopy techniques for visualising the arrangement of minerals and micro-organisms in ice core, coupled with various 'omics' studies of snow and ice. 
 
Pamela E. Rossel, PhD (Postdoc)

 

Pamela is captivated by the molecular messages encoded in complex organic mixtures. Her studies cover a wide range of environments, going from hot hydrothermal systems to cold sediments from the deep Arctic Ocean. Using ultrahigh resolution mass spectrometry, she deciphers these molecular messages to better understand the source and fate of organic carbon species. In the DEEP PURPLE project, she will evaluate microbial carbon dynamics in ice/snow algae dominated systems, with the focus on how particulate and dissolved organic matter are produced, degraded, preserved, and potentially exported.
 
Helene Hoffmann, PhD (incoming Postdoc)

 

Helene is a specialist in chemical and physical techniques to decipher past atmospheric conditions in Alpine and polar ice samples. After a Physics PhD she spent fourteen months in Antarctica as part of the 38th overwintering team at the German research base Neumayer III taking care of the Air Chemistry Observatory. Now she is a postdoc at the University of Cambridge studying paleoclimate proxies in Antarctica as part of the WACSWAIN (Warm Stability of the West Antarctic ice sheet in the last Interglacial) project. In her 1st Deep Purple summer season she will focus on the origin and fate of the dry and wet deposited particulates deposited onto the Greenland ice sheet and their interactions with the microorganisms during blooms.
 
Helen Feord (incoming postdoc) 
 
Helen is currently finishing her PhD at the University of Edinburgh, studying the cellular mechanisms responsible for the daily rhythms of intracellular ion concentrations in a model green alga. Her research examined endogenous circadian rhythms, to understand how eukaryotic cells self-regulate energy availability and use throughout the 24 hours of the day. Building on this project, she is interested in studying biological rhythms and cellular homeostasis in an ecological context, and, in particular, how algal species adapt to stressful and changing conditions. Helen will join DEEP PURPLE as a postdoc to study function of eukaryotic algae present on the Greenland ice sheet. She will study diurnal and seasonal changes in algal community composition and gene expression as well as algal responses to various abiotic stressors. She hopes this will give us a better understanding of how these species both respond to and anticipate dynamic environmental change. 
 
Some highlights from 2019 and 2020.

Our team at the snow/ice interface on Mittivikatt glacier in 2019. Photo: Laura Halbach.

 

The top of the ice core is full of dark material that consists of minerals and many many ice algae that change the watering crust (top-left). Rey Mourot and Martyn Tranter digging a snow pit at QAS-U in 2020 (top-right). At 2 am the sun almost sets in the camp (bottom-left). Photos: Liane G Benning. GrIS 2020 camp as seen from drone (bottom-right). Photo: Rey Mourot.  

 

Picking a camping site and a first helicopter trip

By Rey Mourot 

Hi all! Rey here. I'm the youngest member of the Greenland 2020 team - as my supervisor would say, I'm "the team baby". As a short introduction, I am a future PhD student in Liane's team at the GFZ, and I am the "ice corer" of the Deep Purple team. I will study the organization and composition of microbial communities minerals in the columns of ice, with a special focus on the snow - ice transition - that's where everything happens! I already had (and will have) many "first times" during this expedition! First time in Greenland, first time seeing all kinds of new species of plants and birds, trying new food... But on Friday, June 27 was my first time flying in an helicopter. You should certainly read Martyn's post about our arrival in Narsarsuaq. On our first day here Liane, Martyn and myself had a first look IRL at the ice sheet section we were interested in for setting up our camp. Following many discussion with Jason Box, who will accompany the Deep Purple team for the first part of our Summer 2020 field season, we explored and selected a good camp site. We left the first part of our cargo on the ice, so that we can set the camp fast once our real adventure begins, when the Aarhus team - Eva, Laura, Alex, Lasse, and Jason will join us tomorrow. 

Before flying, in the morning, after hesitation and delays due to low clouds covering the mountains, we received the OK call from Pilu, our helicopter pilot and fixer, that he will come to pick us up in Narsarsuaq airport, direction: the ice sheet! The helicopter was already packed full with Zarges boxes and bags for our field camp.

  

Fig 1. My 1st helicopter experience

As the clouds disappeared, this first flight in the helicopter was crazily beautiful. The surroundings of Narsarsuaq is full of mountains of all sizes, some covered by green mosses and some species of flowers I still need to investigate. The melted snow forms diverse ponds of translucent water reflecting the sun.

 

 

 

Fig 2. My 1st iceberg landscapes

As we flew by I saw my first real icebergs (another first time!, my previous icebergs sightings were on a glacial river in Iceland), small farms, sheep... and finally, the massive ice sheet. Even if it appears bright white on the distance, as we got closer it became clear that the surface was actually pretty dark due to a ton of dark particles (minerals and algae) that we can see from the helicopter. 

 

Fig 3. Dark ice surface next to Nunatak

We asked Pilu about how the ice sheet melted during the past years, and he estimated a retreat of more than 15 meters a year in some places. Even on a marvellous trip like this one, climate change is frightening...

As we finally approached our intended camp site area, Pilu had to try to land at different places. 

There was still plenty of snow (and visible red snow algae) on the ground and we had to land a bit lower to find a perfect spot, but here it is.

For a small insight on how we're choosing it, see below!

Smart criteria for a good camping site:

- on the bare ice: even if we chose a broad area with no big crevasses to set our camp, the snow is covering potential dangerous patches. So, safety first!

- not too far away from a small river, which we will use as drinking water source, water for doing the dishes... and all human functions that we still do, even during a science mission on an ice sheet.

- slightly elevated, so our tents can be kept safe from melted snow / slush avalanches

Science criteria for a good camping site:

- not too far from a promice.dk met station 

- not too far from a Nunatak (rock promontory in the middle of the ice field) where Jason will install a rain gauge to monitor precipitations. 

- not too far from the snow line so we can follow the melt and algal bloom progression and development but still be able to collect good transitional snow to ice samples 

Over the 3 weeks of camping we will have to move our tents regularly anyway, to follow the snow line and find a new, safer, and less wet spot as the landscape is changing. We found the perfect spot, and even saw a beautiful patch of bright red snow algae on the way! Our camp will be at ~710m above sea level. 

Once we arrived, we disembarked and remained on the ice in the brilliant sun and Pilu flaw back to Qakortoq to pick up the remaining boxes that were waiting for us since the spring - sent there for an April mission which I was supposed to be part of and that was supposed to be with Alex, Jason, and Masashi; alas Covid19 happened! 

We were more than happy to stay for one hour and a half on the ice sheet under a bright sun and beautiful blue sky. Let me tell you, time goes fast when you can listen to Martyn and Liane talking about polar bear and research stories in such a cool landscape. As I'm in charge of the GoPro, I was glad to record some of the weird things the PIs could do to celebrate the finding of the-perfect-site!

 

Fig 4. PI’s being silly

We left our boxes on the ice, and they are waiting to be united with the remaining cargo tomorrow when we come back, this time with the full team... 

After a final return flight …. over marvellous landscapes … my 1st ‘helo’ flight was over and we had a well-deserved beer after this successful day!