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Meltwater export of prokaryotic cells from the Greenland ice sheet
Author(s) -
Cameron Karen A.,
Stibal Marek,
Hawkings Jon R.,
Mikkelsen Andreas B.,
Telling Jon,
Kohler Tyler J.,
Gözdereliler Erkin,
Zarsky Jakub D.,
Wadham Jemma L.,
Jacobsen Carsten S.
Publication year - 2017
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13483
Subject(s) - meltwater , greenland ice sheet , fjord , glacier , microbial population biology , ecosystem , biology , bacteroidetes , flux (metallurgy) , oceanography , ecology , geology , bacteria , 16s ribosomal rna , chemistry , paleontology , organic chemistry
Summary 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 × 10 4 cells mL −1 and we estimate that ∼1.02 × 10 21 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.