Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach
The Arctic terrestrial environment harbors a complex mosaic of mercury (Hg) and carbon (C) reservoirs, some of which are rapidly destabilizing in response to climate warming. The sources of riverine Hg across the Mackenzie River basin (MRB) are uncertain, which leads to a poor understanding of poten...
Published in: | Science of The Total Environment |
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Language: | English |
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Uppsala universitet, Luft-, vatten- och landskapslära
2022
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458134 https://doi.org/10.1016/j.scitotenv.2021.150808 |
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ftuppsalauniv:oai:DiVA.org:uu-458134 2024-02-11T10:01:09+01:00 Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach Campeau, Audrey Eklöf, Karin Soerensen, Anne L. Åkerblom, Staffan Yuan, Shengliu Hintelmann, Holger Bieroza, Magdalena Köhler, Stephan Zdanowicz, Christian 2022 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458134 https://doi.org/10.1016/j.scitotenv.2021.150808 eng eng Uppsala universitet, Luft-, vatten- och landskapslära Depatment of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden Department of Environmental Research and Monitoring, Swedish Museum of Natural History, Sweden Statistiska centralbyrån (SCB), Statistic Sweden, Stockholm, Sweden Water Quality Center, Trent University, Peterborough, Ontario, Canada Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden Elsevier BV Science of the Total Environment, 0048-9697, 2022, 806:4, orcid:0000-0002-9113-8915 orcid:0000-0002-1045-5063 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458134 doi:10.1016/j.scitotenv.2021.150808 PMID 34637879 ISI:000744101000003 info:eu-repo/semantics/openAccess Pollution Waste Management and Disposal Environmental Chemistry Environmental Engineering Geochemistry Geokemi Article in journal info:eu-repo/semantics/article text 2022 ftuppsalauniv https://doi.org/10.1016/j.scitotenv.2021.150808 2024-01-17T23:32:13Z The Arctic terrestrial environment harbors a complex mosaic of mercury (Hg) and carbon (C) reservoirs, some of which are rapidly destabilizing in response to climate warming. The sources of riverine Hg across the Mackenzie River basin (MRB) are uncertain, which leads to a poor understanding of potential future release. Measurements of dissolved and particulate mercury (DHg, PHg) and carbon (DOC, POC) concentration were performed, along with analyses of Hg stable isotope ratios (incl. ∆199Hg, d202Hg), radiocarbon content (∆14C) and optical properties of DOC of river water. Isotopic ratios of Hg revealed a closer association to terrestrial Hg reservoirs for the particulate fraction, while the dissolved fraction was more closely associated with atmospheric deposition sources of shorter turnover time. There was a positive correlation between the ∆14C-OC and riverine Hg concentration for both particulate and dissolved fractions, indicating that waters transporting older-OC (14C-depleted) also contained higher levels of Hg. In the dissolved fraction, older DOC was also associated with higher molecular weight, aromaticity and humic content, which are likely associated with higher Hg-binding potential. Riverine PHg concentration increased with turbidity and SO4 concentration. There were large contrasts in Hg concentration and OC age and quality among the mountain and lowland sectors of the MRB, which likely reflect the spatial distribution of various terrestrial Hg and OC reservoirs, including weathering of sulfate minerals, erosion and extraction of coal deposits, thawing permafrost, forest fires, peatlands, and forests. Results revealed major differences in the sources of particulate and dissolved riverine Hg, but nonetheless a common positive association with older riverine OC. These findings reveal that a complex mixture of Hg sources, supplied across the MRB, will contribute to future trends in Hg export to the Arctic Ocean under rapid environmental changes. Article in Journal/Newspaper Arctic Arctic Ocean Mackenzie river permafrost Uppsala University: Publications (DiVA) Arctic Arctic Ocean Mackenzie River Science of The Total Environment 806 150808 |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Pollution Waste Management and Disposal Environmental Chemistry Environmental Engineering Geochemistry Geokemi |
spellingShingle |
Pollution Waste Management and Disposal Environmental Chemistry Environmental Engineering Geochemistry Geokemi Campeau, Audrey Eklöf, Karin Soerensen, Anne L. Åkerblom, Staffan Yuan, Shengliu Hintelmann, Holger Bieroza, Magdalena Köhler, Stephan Zdanowicz, Christian Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach |
topic_facet |
Pollution Waste Management and Disposal Environmental Chemistry Environmental Engineering Geochemistry Geokemi |
description |
The Arctic terrestrial environment harbors a complex mosaic of mercury (Hg) and carbon (C) reservoirs, some of which are rapidly destabilizing in response to climate warming. The sources of riverine Hg across the Mackenzie River basin (MRB) are uncertain, which leads to a poor understanding of potential future release. Measurements of dissolved and particulate mercury (DHg, PHg) and carbon (DOC, POC) concentration were performed, along with analyses of Hg stable isotope ratios (incl. ∆199Hg, d202Hg), radiocarbon content (∆14C) and optical properties of DOC of river water. Isotopic ratios of Hg revealed a closer association to terrestrial Hg reservoirs for the particulate fraction, while the dissolved fraction was more closely associated with atmospheric deposition sources of shorter turnover time. There was a positive correlation between the ∆14C-OC and riverine Hg concentration for both particulate and dissolved fractions, indicating that waters transporting older-OC (14C-depleted) also contained higher levels of Hg. In the dissolved fraction, older DOC was also associated with higher molecular weight, aromaticity and humic content, which are likely associated with higher Hg-binding potential. Riverine PHg concentration increased with turbidity and SO4 concentration. There were large contrasts in Hg concentration and OC age and quality among the mountain and lowland sectors of the MRB, which likely reflect the spatial distribution of various terrestrial Hg and OC reservoirs, including weathering of sulfate minerals, erosion and extraction of coal deposits, thawing permafrost, forest fires, peatlands, and forests. Results revealed major differences in the sources of particulate and dissolved riverine Hg, but nonetheless a common positive association with older riverine OC. These findings reveal that a complex mixture of Hg sources, supplied across the MRB, will contribute to future trends in Hg export to the Arctic Ocean under rapid environmental changes. |
format |
Article in Journal/Newspaper |
author |
Campeau, Audrey Eklöf, Karin Soerensen, Anne L. Åkerblom, Staffan Yuan, Shengliu Hintelmann, Holger Bieroza, Magdalena Köhler, Stephan Zdanowicz, Christian |
author_facet |
Campeau, Audrey Eklöf, Karin Soerensen, Anne L. Åkerblom, Staffan Yuan, Shengliu Hintelmann, Holger Bieroza, Magdalena Köhler, Stephan Zdanowicz, Christian |
author_sort |
Campeau, Audrey |
title |
Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach |
title_short |
Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach |
title_full |
Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach |
title_fullStr |
Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach |
title_full_unstemmed |
Sources of riverine mercury across the Mackenzie River Basin : inferences from a combined Hg C isotopes and optical properties approach |
title_sort |
sources of riverine mercury across the mackenzie river basin : inferences from a combined hg c isotopes and optical properties approach |
publisher |
Uppsala universitet, Luft-, vatten- och landskapslära |
publishDate |
2022 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458134 https://doi.org/10.1016/j.scitotenv.2021.150808 |
geographic |
Arctic Arctic Ocean Mackenzie River |
geographic_facet |
Arctic Arctic Ocean Mackenzie River |
genre |
Arctic Arctic Ocean Mackenzie river permafrost |
genre_facet |
Arctic Arctic Ocean Mackenzie river permafrost |
op_relation |
Science of the Total Environment, 0048-9697, 2022, 806:4, orcid:0000-0002-9113-8915 orcid:0000-0002-1045-5063 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458134 doi:10.1016/j.scitotenv.2021.150808 PMID 34637879 ISI:000744101000003 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.scitotenv.2021.150808 |
container_title |
Science of The Total Environment |
container_volume |
806 |
container_start_page |
150808 |
_version_ |
1790596906531946496 |