Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada
Abstract In arctic and sub‐arctic environments, mercury (Hg), more specifically toxic methylmercury (MeHg), is of growing concern to local communities because of its accumulation in fish. In these regions, there is particular interest in the potential mobilization of atmospherically deposited Hg seq...
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crwiley:10.1002/hyp.10911 2024-06-02T08:01:58+00:00 Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada Gordon, J. Quinton, W. Branfireun, B. A. Olefeldt, D. Canadian Space Agency 2016 http://dx.doi.org/10.1002/hyp.10911 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.10911 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.10911 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Hydrological Processes volume 30, issue 20, page 3627-3638 ISSN 0885-6087 1099-1085 journal-article 2016 crwiley https://doi.org/10.1002/hyp.10911 2024-05-03T10:34:23Z Abstract In arctic and sub‐arctic environments, mercury (Hg), more specifically toxic methylmercury (MeHg), is of growing concern to local communities because of its accumulation in fish. In these regions, there is particular interest in the potential mobilization of atmospherically deposited Hg sequestered in permafrost that is thawing at unprecedented rates. Permafrost thaw and the resulting ground surface subsidence transforms forested peat plateaus into treeless and permafrost‐free thermokarst wetlands where inorganic Hg released from the thawed permafrost and draining from the surrounding peat plateaus may be transformed to MeHg. This study begins to characterize the spatial distribution of MeHg in a peat plateau–thermokarst wetland complex, a feature that prevails throughout the wetland‐dominated southern margin of thawing discontinuous permafrost in Canada's Northwest Territories. We measured pore water total Hg, MeHg, dissolved organic matter characteristics and general water chemistry parameters to evaluate the role of permafrost thaw on the pattern of water chemistry. A gradient in vegetation composition, water chemistry and dissolved organic matter characteristics followed a toposequence from the ombrotrophic bogs near the crest of the complex to poor fens at its downslope margins. We found that pore waters in poor fens contained elevated levels of MeHg, and the water draining from these features had dissolved MeHg concentrations 4.5 to 14.5 times higher than the water draining from the bogs. It was determined through analysis of historical aerial images that the poor fens in the toposequence had formed relatively recently (early 1970s) as a result of permafrost thaw. Differences between the fens and bogs are likely to be a result of their differences in groundwater function, and this suggests that permafrost thaw in this landscape can result in hotspots for Hg methylation that are hydrologically connected to downstream ecosystems. Copyright © 2016 John Wiley & Sons, Ltd. Article in Journal/Newspaper Arctic Northwest Territories Peat Peat plateau permafrost Thermokarst Wiley Online Library Arctic Canada Northwest Territories Hydrological Processes 30 20 3627 3638 |
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Open Polar |
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Wiley Online Library |
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language |
English |
description |
Abstract In arctic and sub‐arctic environments, mercury (Hg), more specifically toxic methylmercury (MeHg), is of growing concern to local communities because of its accumulation in fish. In these regions, there is particular interest in the potential mobilization of atmospherically deposited Hg sequestered in permafrost that is thawing at unprecedented rates. Permafrost thaw and the resulting ground surface subsidence transforms forested peat plateaus into treeless and permafrost‐free thermokarst wetlands where inorganic Hg released from the thawed permafrost and draining from the surrounding peat plateaus may be transformed to MeHg. This study begins to characterize the spatial distribution of MeHg in a peat plateau–thermokarst wetland complex, a feature that prevails throughout the wetland‐dominated southern margin of thawing discontinuous permafrost in Canada's Northwest Territories. We measured pore water total Hg, MeHg, dissolved organic matter characteristics and general water chemistry parameters to evaluate the role of permafrost thaw on the pattern of water chemistry. A gradient in vegetation composition, water chemistry and dissolved organic matter characteristics followed a toposequence from the ombrotrophic bogs near the crest of the complex to poor fens at its downslope margins. We found that pore waters in poor fens contained elevated levels of MeHg, and the water draining from these features had dissolved MeHg concentrations 4.5 to 14.5 times higher than the water draining from the bogs. It was determined through analysis of historical aerial images that the poor fens in the toposequence had formed relatively recently (early 1970s) as a result of permafrost thaw. Differences between the fens and bogs are likely to be a result of their differences in groundwater function, and this suggests that permafrost thaw in this landscape can result in hotspots for Hg methylation that are hydrologically connected to downstream ecosystems. Copyright © 2016 John Wiley & Sons, Ltd. |
author2 |
Canadian Space Agency |
format |
Article in Journal/Newspaper |
author |
Gordon, J. Quinton, W. Branfireun, B. A. Olefeldt, D. |
spellingShingle |
Gordon, J. Quinton, W. Branfireun, B. A. Olefeldt, D. Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada |
author_facet |
Gordon, J. Quinton, W. Branfireun, B. A. Olefeldt, D. |
author_sort |
Gordon, J. |
title |
Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada |
title_short |
Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada |
title_full |
Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada |
title_fullStr |
Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada |
title_full_unstemmed |
Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, Northwest Territories, Canada |
title_sort |
mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex, northwest territories, canada |
publisher |
Wiley |
publishDate |
2016 |
url |
http://dx.doi.org/10.1002/hyp.10911 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.10911 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.10911 |
geographic |
Arctic Canada Northwest Territories |
geographic_facet |
Arctic Canada Northwest Territories |
genre |
Arctic Northwest Territories Peat Peat plateau permafrost Thermokarst |
genre_facet |
Arctic Northwest Territories Peat Peat plateau permafrost Thermokarst |
op_source |
Hydrological Processes volume 30, issue 20, page 3627-3638 ISSN 0885-6087 1099-1085 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/hyp.10911 |
container_title |
Hydrological Processes |
container_volume |
30 |
container_issue |
20 |
container_start_page |
3627 |
op_container_end_page |
3638 |
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1800746460274229248 |