Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic
© 2015 Association for the Sciences of Limnology and Oceanography. Permafrost thaw lakes occur in high abundance across the subarctic landscape but little is known about their limnological dynamics. This study was undertaken to evaluate the hourly, seasonal, and depth variations in oxygen concentrat...
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Language: | English |
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2015
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ftcdlib:qt6sn3b5hv 2023-05-15T16:37:22+02:00 Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic Deshpande, BN Macintyre, S Matveev, A Vincent, WF 1656 - 1670 2015-09-01 application/pdf http://www.escholarship.org/uc/item/6sn3b5hv english eng eScholarship, University of California qt6sn3b5hv http://www.escholarship.org/uc/item/6sn3b5hv public Deshpande, BN; Macintyre, S; Matveev, A; & Vincent, WF. (2015). Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic. Limnology and Oceanography, 60(5), 1656 - 1670. doi:10.1002/lno.10126. UC Santa Barbara: Retrieved from: http://www.escholarship.org/uc/item/6sn3b5hv article 2015 ftcdlib https://doi.org/10.1002/lno.10126 2017-10-13T22:54:11Z © 2015 Association for the Sciences of Limnology and Oceanography. Permafrost thaw lakes occur in high abundance across the subarctic landscape but little is known about their limnological dynamics. This study was undertaken to evaluate the hourly, seasonal, and depth variations in oxygen concentration in three thaw lakes in northern Quebec, Canada, across contrasting permafrost regimes (isolated, sporadic, and discontinuous). All lakes were well stratified in summer despite their shallow depths (2.7-4.0m), with hypoxic or anoxic bottom waters. Continuous automated measurements in each of the lakes showed a period of water column oxygenation over several weeks in fall followed by bottom-water anoxia soon after ice-up. Anoxic conditions extended to shallower depths (1m) over the course of winter, beginning 18-137 d after ice formation, depending on the lake. Full water column anoxia extended over 33-75% of the annual record. There was a brief period of incomplete spring mixing with partial or no reoxygenation of the bottom waters in each lake. Conductivity measurements showed the build-up of solutes in the bottom waters, and the resultant density increase contributed to the resistance to full mixing in spring. These observations indicate the prevalence of stratified conditions throughout most of the year and underscore the importance of the fall mixing period for gas exchange with the atmosphere. Given the long duration of anoxia, subarctic thaw lakes represent an ideal environment for anaerobic processes such as methane production. The intermittent oxygenation also favors intense methanotrophy and aerobic bacterial decomposition processes. Article in Journal/Newspaper Ice permafrost Subarctic University of California: eScholarship Canada Limnology and Oceanography 60 5 1656 1670 |
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Open Polar |
collection |
University of California: eScholarship |
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ftcdlib |
language |
English |
description |
© 2015 Association for the Sciences of Limnology and Oceanography. Permafrost thaw lakes occur in high abundance across the subarctic landscape but little is known about their limnological dynamics. This study was undertaken to evaluate the hourly, seasonal, and depth variations in oxygen concentration in three thaw lakes in northern Quebec, Canada, across contrasting permafrost regimes (isolated, sporadic, and discontinuous). All lakes were well stratified in summer despite their shallow depths (2.7-4.0m), with hypoxic or anoxic bottom waters. Continuous automated measurements in each of the lakes showed a period of water column oxygenation over several weeks in fall followed by bottom-water anoxia soon after ice-up. Anoxic conditions extended to shallower depths (1m) over the course of winter, beginning 18-137 d after ice formation, depending on the lake. Full water column anoxia extended over 33-75% of the annual record. There was a brief period of incomplete spring mixing with partial or no reoxygenation of the bottom waters in each lake. Conductivity measurements showed the build-up of solutes in the bottom waters, and the resultant density increase contributed to the resistance to full mixing in spring. These observations indicate the prevalence of stratified conditions throughout most of the year and underscore the importance of the fall mixing period for gas exchange with the atmosphere. Given the long duration of anoxia, subarctic thaw lakes represent an ideal environment for anaerobic processes such as methane production. The intermittent oxygenation also favors intense methanotrophy and aerobic bacterial decomposition processes. |
format |
Article in Journal/Newspaper |
author |
Deshpande, BN Macintyre, S Matveev, A Vincent, WF |
spellingShingle |
Deshpande, BN Macintyre, S Matveev, A Vincent, WF Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
author_facet |
Deshpande, BN Macintyre, S Matveev, A Vincent, WF |
author_sort |
Deshpande, BN |
title |
Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
title_short |
Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
title_full |
Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
title_fullStr |
Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
title_full_unstemmed |
Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
title_sort |
oxygen dynamics in permafrost thaw lakes: anaerobic bioreactors in the canadian subarctic |
publisher |
eScholarship, University of California |
publishDate |
2015 |
url |
http://www.escholarship.org/uc/item/6sn3b5hv |
op_coverage |
1656 - 1670 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Ice permafrost Subarctic |
genre_facet |
Ice permafrost Subarctic |
op_source |
Deshpande, BN; Macintyre, S; Matveev, A; & Vincent, WF. (2015). Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic. Limnology and Oceanography, 60(5), 1656 - 1670. doi:10.1002/lno.10126. UC Santa Barbara: Retrieved from: http://www.escholarship.org/uc/item/6sn3b5hv |
op_relation |
qt6sn3b5hv http://www.escholarship.org/uc/item/6sn3b5hv |
op_rights |
public |
op_doi |
https://doi.org/10.1002/lno.10126 |
container_title |
Limnology and Oceanography |
container_volume |
60 |
container_issue |
5 |
container_start_page |
1656 |
op_container_end_page |
1670 |
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1766027659392843776 |