Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic
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 contrast...
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ftcdlib:oai:escholarship.org/ark:/13030/qt6sn3b5hv 2023-05-15T16:37:19+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 https://escholarship.org/uc/item/6sn3b5hv unknown eScholarship, University of California qt6sn3b5hv https://escholarship.org/uc/item/6sn3b5hv public Limnology and Oceanography, vol 60, iss 5 Marine Biology & Hydrobiology Earth Sciences Environmental Sciences Biological Sciences article 2015 ftcdlib 2021-04-16T07:10:16Z 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 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Marine Biology & Hydrobiology Earth Sciences Environmental Sciences Biological Sciences |
spellingShingle |
Marine Biology & Hydrobiology Earth Sciences Environmental Sciences Biological Sciences Deshpande, BN Macintyre, S Matveev, A Vincent, WF Oxygen dynamics in permafrost thaw lakes: Anaerobic bioreactors in the Canadian subarctic |
topic_facet |
Marine Biology & Hydrobiology Earth Sciences Environmental Sciences Biological Sciences |
description |
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 |
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 |
https://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 |
Limnology and Oceanography, vol 60, iss 5 |
op_relation |
qt6sn3b5hv https://escholarship.org/uc/item/6sn3b5hv |
op_rights |
public |
_version_ |
1766027608108040192 |