Field Lab in Pole Position

Dallmann Laboratory on King George Island tends to be overlooked, despite the fact that it is located on the Antarctic Peninsula, the part of the Antarctic where the effects of climate change are most visible – and AWI doctoral candidate Ralf Hoffmann, the perfect place to get to the bottom of those effects. Freshly returned from his first Dallmann expedition, in the following he reports on his experiences. Recorded by Kristina Bär.

When I first saw the spurs of Fourcade Glacier, the last rays of sunshine were falling on the red laboratory and housing containers of Dallmann Laboratory at the Argentinian Carlini Station. We’d finally reached our destination.

At that point, we already had a small odyssey behind us: the long flight to Buenos Aires, then a few days of layover until the Argentinian Air Force plane was ready to set course for the Antarctic, and finally the voyage by ship, following the coast of King George Island to Potter Cove.

What comes next for me: five weeks of diving and conducting underwater experiments, collecting and analysing samples. I want to explore how much oxygen life forms on the local seafloor consume and how life in the sediment is changing as the glaciers recede.

For our work Potter Cove, where Dallmann Laboratory lies, is essentially a ten-square-kilometre outdoor laboratory. We’re right in the middle of the action, so to speak, because climate change is especially apparent on the Antarctic Peninsula. Over the past 50 years, the tongue of the Fourcade Glacier has receded by more than a kilometre.

During my stay, I’ll collect samples at three different sites that up until recently were still covered by ice. By doing so, I hope to discover how long it takes for new species to move in and native ones to disappear – because the shrinking ice masses not only create new habitats; they also transform old ones.

For example, the glacier’s intensifying meltwater flows are washing large quantities of sediment into the cove. They cloud the water so that sunlight can hardly penetrate it, a change that in turn influences e.g. the depths at which certain algae can still be found.

My findings will hopefully be one of many puzzle pieces that will eventually offer us a comprehensive image of how climate change is reshaping the ecosystem of an entire cove.

Further biologists like my AWI colleague Katharina Zacher, as well as glaciologists, geologists and biogeochemists, are also pursuing research in Potter Cove. Within the context of IMCONet, a research network headed by AWI biologist Doris Abele and funded by the EU, our goal is to develop an ecosystem model that includes geographic and chronological aspects, which will allow us to more accurately predict future changes.

Our greatest advantage: thanks to Dallmann Laboratory we have access to summer and winter data from the past 25 years – a veritable treasure trove in the Antarctic, these datasets were and are painstakingly collected by the Argentinian researchers overwintering at Carlini Station. To the present day, they continue to examine plankton and algae, collect water samples and monitor growth panels during the harsh winter months.

A special highlight of this expedition: it marks the first time ever that German, Swedish and Italian researchers are diving together with the Argentinians. Though there were some initial worries about language barriers, in fact it all went quite smoothly, so well that in October 2015 the same international team will return to make further dives in Potter Cove.