A microbial ecosystem beneath the West Antarctic ice sheet
- Christner, Brent C. [ Department of Biological Sciences, Louisiana State University ]
- Priscu, John C. [ Montana State University: Land Resources & Environmental Sciences ]
- Acheberger, Amanda M. [ Department of Biological Sciences, Louisiana State University ]
- Barbante, Carlo [ Institute for the Dynamics of Environmental Processes – CNR, Venice, and Department of Environmental Sciences, Informatics and Statistics, Ca′Foscari University of Venice ]
- Carter, Sasha P. [ Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego ]
- Christianson, Knut [ Physics Department, St Olaf College ]
- Michaud, Alexander B. [ Montana State University: Land Resources & Environmental Sciences ]
- Mikucki, Jill A. [ Department of Microbiology, University of Tennessee ]
- Mitchell, Andrew C. [ Department of Geography and Earth Sciences, Aberystwyth University ]
- Skidmore, Mark L. [ Montana State University: Earth Sciences ]
- Vick-Majors, Trista J. [ Montana State University: Land Resources & Environmental Sciences ]
- the WISSARD Science Team
Liquid water has been known to occur beneath the Antarctic ice sheet for more than 40 years1, but only recently have these subglacial aqueous environments been recognized as microbial ecosystems that may influence biogeochemical transformations on a global scale2, 3, 4. Here we present the first geomicrobiological description of water and surficial sediments obtained from direct sampling of a subglacial Antarctic lake. Subglacial Lake Whillans (SLW) lies beneath approximately 800 m of ice on the lower portion of the Whillans Ice Stream (WIS) in West Antarctica and is part of an extensive and evolving subglacial drainage network5. The water column of SLW contained metabolically active microorganisms and was derived primarily from glacial ice melt with solute sources from lithogenic weathering and a minor seawater component. Heterotrophic and autotrophic production data together with small subunit ribosomal RNA gene sequencing and biogeochemical data indicate that SLW is a chemosynthetically driven ecosystem inhabited by a diverse assemblage of bacteria and archaea. Our results confirm that aquatic environments beneath the Antarctic ice sheet support viable microbial ecosystems, corroborating previous reports suggesting that they contain globally relevant pools of carbon and microbes2, 4 that can mobilize elements from the lithosphere6 and influence Southern Ocean geochemical and biological systems7.