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Kohler TJ, Vinšová P, Falteisek L, Žárský JD, Yde JC, Hatton JE, Hawkings JR, Lamarche-Gagnon G, Hood E, Cameron KA, Stibal M. Patterns in Microbial Assemblages Exported From the Meltwater of Arctic and Sub-Arctic Glaciers. Front Microbiol 2020; 11:669. [PMID: 32351489 PMCID: PMC7174618 DOI: 10.3389/fmicb.2020.00669] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/24/2020] [Indexed: 01/14/2023] Open
Abstract
Meltwater streams connect the glacial cryosphere with downstream ecosystems. Dissolved and particulate matter exported from glacial ecosystems originates from contrasting supraglacial and subglacial environments, and exported microbial cells have the potential to serve as ecological and hydrological indicators for glacial ecosystem processes. Here, we compare exported microbial assemblages from the meltwater of 24 glaciers from six (sub)Arctic regions – the southwestern Greenland Ice Sheet, Qeqertarsuaq (Disko Island) in west Greenland, Iceland, Svalbard, western Norway, and southeast Alaska – differing in their lithology, catchment size, and climatic characteristics, to investigate spatial and environmental factors structuring exported meltwater assemblages. We found that 16S rRNA gene sequences of all samples were dominated by the phyla Proteobacteria, Bacteroidetes, and Actinobacteria, with Verrucomicrobia also common in Greenland localities. Clustered OTUs were largely composed of aerobic and anaerobic heterotrophs capable of degrading a wide variety of carbon substrates. A small number of OTUs dominated all assemblages, with the most abundant being from the genera Polaromonas, Methylophilus, and Nitrotoga. However, 16–32% of a region’s OTUs were unique to that region, and rare taxa revealed unique metabolic potentials and reflected differences between regions, such as the elevated relative abundances of sulfur oxidizers Sulfuricurvum sp. and Thiobacillus sp. at Svalbard sites. Meltwater alpha diversity showed a pronounced decrease with increasing latitude, and multivariate analyses of assemblages revealed significant regional clusters. Distance-based redundancy and correlation analyses further resolved associations between whole assemblages and individual OTUs with variables primarily corresponding with the sampled regions. Interestingly, some OTUs indicating specific metabolic processes were not strongly associated with corresponding meltwater characteristics (e.g., nitrification and inorganic nitrogen concentrations). Thus, while exported assemblage structure appears regionally specific, and probably reflects differences in dominant hydrological flowpaths, OTUs can also serve as indicators for more localized microbially mediated processes not captured by the traditional characterization of bulk meltwater hydrochemistry. These results collectively promote a better understanding of microbial distributions across the Arctic, as well as linkages between the terrestrial cryosphere habitats and downstream ecosystems.
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Affiliation(s)
- Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.,Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Petra Vinšová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Lukáš Falteisek
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jakub D Žárský
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jacob C Yde
- Department of Environmental Sciences, Western Norway University of Applied Sciences, Sogndal, Norway
| | - Jade E Hatton
- School of Earth Sciences, University of Bristol, Bristol, United Kingdom
| | - Jon R Hawkings
- National High Magnetic Field Laboratory, Department of Earth, Ocean & Atmospheric Science, Florida State University, Tallahassee, FL, United States.,GFZ German Research Centre for Geosciences, Potsdam, Germany
| | | | - Eran Hood
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK, United States
| | - Karen A Cameron
- Institute of Biological, Environmental and Rural Sciences, Faculty of Earth and Life Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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Hatton JE, Hendry KR, Hawkings JR, Wadham JL, Opfergelt S, Kohler TJ, Yde JC, Stibal M, Žárský JD. Silicon isotopes in Arctic and sub-Arctic glacial meltwaters: the role of subglacial weathering in the silicon cycle. Proc Math Phys Eng Sci 2019; 475:20190098. [PMID: 31534420 PMCID: PMC6735475 DOI: 10.1098/rspa.2019.0098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/16/2019] [Indexed: 11/12/2022] Open
Abstract
Glacial environments play an important role in high-latitude marine nutrient cycling, potentially contributing significant fluxes of silicon (Si) to the polar oceans, either as dissolved silicon (DSi) or as dissolvable amorphous silica (ASi). Silicon is a key nutrient in promoting marine primary productivity, contributing to atmospheric CO2 removal. We present the current understanding of Si cycling in glacial systems, focusing on the Si isotope (δ30Si) composition of glacial meltwaters. We combine existing glacial δ30Si data with new measurements from 20 sub-Arctic glaciers, showing that glacial meltwaters consistently export isotopically light DSi compared with non-glacial rivers (+0.16‰ versus +1.38‰). Glacial δ30SiASi composition ranges from −0.05‰ to −0.86‰ but exhibits low seasonal variability. Silicon fluxes and δ30Si composition from glacial systems are not commonly included in global Si budgets and isotopic mass balance calculations at present. We discuss outstanding questions, including the formation mechanism of ASi and the export of glacial nutrients from fjords. Finally, we provide a contextual framework for the recent advances in our understanding of subglacial Si cycling and highlight critical research avenues for assessing potential future changes in these environments.
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Affiliation(s)
- Jade E Hatton
- School of Earth Sciences, University of Bristol, Bristol, UK
| | | | - Jonathan R Hawkings
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.,German Research Centre for Geosciences GFZ, Potsdam, Germany
| | - Jemma L Wadham
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Sophie Opfergelt
- Earth and Life Institute, Environmental Sciences, Université Catholique de Louvain, L7.05.10, 1348, Louvain-la-Neuve, Belgium
| | - Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.,Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jacob C Yde
- Department of Environmental Sciences, Western Norway University of Applied Sciences, Sogndal, Norway
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jakub D Žárský
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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Žárský JD, Kohler TJ, Yde JC, Falteisek L, Lamarche-Gagnon G, Hawkings JR, Hatton JE, Stibal M. Prokaryotic assemblages in suspended and subglacial sediments within a glacierized catchment on Qeqertarsuaq (Disko Island), west Greenland. FEMS Microbiol Ecol 2018; 94:5017442. [DOI: 10.1093/femsec/fiy100] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 05/27/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jakub D Žárský
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
| | - Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
| | - Jacob C Yde
- Department of Environment Sciences, Western Norway University of Applied Sciences, Royrgata 6, 6856 Sogndal, Norway
| | - Lukáš Falteisek
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
| | - Guillaume Lamarche-Gagnon
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - Jon R Hawkings
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - Jade E Hatton
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Vinicna 7, 128 44 Prague 2, Czechia
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