Meltwater export of prokaryotic cells from the Greenland ice sheet

Cameron, K. A. , Stibal, M., Hawkings, J. R., Mikkelsen, A. B., Telling, J., Kohler, T. J., Gözdereliler, E., Zarsky, J. D., Wadham, J. L. and Jacobsen, C. S. (2017) Meltwater export of prokaryotic cells from the Greenland ice sheet. Environmental Microbiology, 19(2), pp. 524-534. (doi: 10.1111/1462-2920.13483) (PMID:27489963)

Abstract

Microorganisms are flushed from the Greenland Ice Sheet (GrIS) where they may contribute towards the nutrient cycling and community compositions of downstream ecosystems. We investigate meltwater microbial assemblages as they exit the GrIS from a large outlet glacier, and as they enter a downstream river delta during the record melt year of 2012. Prokaryotic abundance, flux and community composition was studied, and factors affecting community structures were statistically considered. The mean concentration of cells exiting the ice sheet was 8.30 × 104 cells mL−1 and we estimate that ∼1.02 × 1021 cells were transported to the downstream fjord in 2012, equivalent to 30.95 Mg of carbon. Prokaryotic microbial assemblages were dominated by Proteobacteria, Bacteroidetes, and Actinobacteria. Cell concentrations and community compositions were stable throughout the sample period, and were statistically similar at both sample sites. Based on our observations, we argue that the subglacial environment is the primary source of the river-transported microbiota, and that cell export from the GrIS is dependent on discharge. We hypothesise that the release of subglacial microbiota to downstream ecosystems will increase as freshwater flux from the GrIS rises in a warming world.

• Item Type: Articles
• Additional Information: This research was funded by Danish Research Council grants FNU 10‐085274 to CJ and CENPERM DNRF100. It has additionally been supported by a NERC grant NE/I008845/1 to JLW, and by a Czech Science Foundation grant GACR 15‐17346Y to MS. We thank Pernille Stockmarr for technical assistance.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cameron, Dr Karen
• Authors: Cameron, K. A., Stibal, M., Hawkings, J. R., Mikkelsen, A. B., Telling, J., Kohler, T. J., Gözdereliler, E., Zarsky, J. D., Wadham, J. L., and Jacobsen, C. S.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences
• Journal Name: Environmental Microbiology
• Publisher: Wiley-Blackwell Publishing Ltd.
• ISSN: 1462-2912
• ISSN (Online): 1462-2920
• Published Online: 30 August 2016
• Copyright Holders: Copyright © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd
• First Published: First published in Environmental Microbiology 19(2):524-534
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher