Dissolved Organic Matter in Antarctica
What Are They Doing?
An interdisciplinary research team collected water and ice cores to study the microbial communities found in the Transantarctic Mountains and the McMurdo Dry Valleys in Antarctica. Once believed to be devoid of life, closer observations of glacial ice have revealed microhabitats teeming with life. In these extreme conditions, microorganisms live in the liquid water phases of ice, and they depend upon dissolved organic matter (DOM) in the water for food and nutrients. Although DOM is found in every environment and is an important component of the global carbon cycle, we still need more basic information about it, such as how DOM forms and changes over time.
The research team compared the microbes and DOM in two different types of Antarctic streams: normal streams that flow out of a lake and a supraglacial stream that forms on top of a glacier each summer. Because the supraglacial stream forms each year from a relatively clean surface, the investigators had a unique chance to study how the microbial community and DOM start from scratch and develop over time. By isolating the DOM and studying its chemical and structural composition, the team learned more about how the contributions and interactions between microbes and the DOM pool are different in the two different types of streams.
In addition, it is not well known how DOM and carbon locked in glacial ice will respond to climate change. The connection between ice-bound DOM and climate change is important because frozen environments comprise 25% of the Earth's surface, potentially releasing additional carbon into the atmosphere as global temperatures warm.
Where Are They?
The team had a lab in McMurdo Station, but spent most of their time working at a base camp at Lake Fryxell in the McMurdo Dry Valleys of Antarctica. The McMurdo Dry Valleys are located on the western coast of McMurdo Sound (77°00' S, 162° 52' E) and form the largest relatively ice-free area on the Antarctic continent. The team studied the streams in the Fryxell basin in order to compare these to the supraglacial stream on the Cotton Glacier.
The Cotton Glacier lies in the Transantarctic Mountains north of Cape Roberts (77° 07' S, 161° 40' E) in Antarctica. The unique fluvial system that forms on the Cotton Glacier results from the prevailing winds which deposit debris on the surface of the glacier. Heating of the dark debris warms the surface, melting the ice, and generating large quantities of meltwater which were essential for the project's data collection.
The Lake Fryxell basin is up valley from Lake Bonney, which is the location of the Microorganisms in Antarctic Glacier Ice PolarTREC project.
Meet the Team
Sarah Diers has worn many professional hats in her life…commercial crab and salmon fisher in Alaska, fisheries biologist, coffee barista, whale watching naturalist, caterer and most recently, middle school science teacher. She is very excited to add the “hat” of PolarTREC participant to her collection. Sarah has dreamt of visiting our Earth’s great Southern continent since she was a child. She cannot wait to share her expedition with Polar students of all ages. Sarah invites you to become an active participant in the Dissolved Organic Matter expedition- ask her team questions, join the webinars, read the journals, wonder and explore Antarctica with her.
Dr. Yu-Ping (Yo) Chin, is a Professor of Geology at Ohio State University. Dr. Chin is an aquatic geochemist and hydrogeologist whose research interests range from photolytic degradation of environmental contaminants and contaminant reduction to the role of natural organic matter in environmental oxidation/reduction processes.
Dr. Christine Foreman is an Associate Research Professor at Montana State University at the Center for Biofilm Engineering and the Department of Land Resources and Environmental Sciences. Dr. Foreman has spent seven seasons in Antarctica studying life in extreme conditions, connecting the very smallest organisms to the workings of the entire planet. Her research revolves around the organization of microbial communities in relation to their physical environment, and the processing of nutrients and dissolved organic matter (DOM). In her spare time, Dr. Foreman enjoys being outdoors, hiking, and fly-fishing with her friends, husband, Toby, two sons, Alex and Matthew, and two dogs, Táo and Tye. Dr. Diane McKnight is a Professor at the Institute of Arctic and Alpine Research at the University of Colorado-Boulder. Dr. McKnight is a Principal Investigator with the McMurdo Dry Valleys and Niwot Ridge Long Term Ecological Research Groups. Her research focuses on interactions between hydrologic, chemical and biological processes in controlling the dynamics in aquatic ecosystems. This research is carried out through field-scale experiments, modeling, and laboratory characterization of natural substrates.