1
|
Fabre C, Sonke JE, Tananaev N, Teisserenc R. Organic carbon and mercury exports from pan-Arctic rivers in a thawing permafrost context - A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176713. [PMID: 39389136 DOI: 10.1016/j.scitotenv.2024.176713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2024] [Revised: 09/06/2024] [Accepted: 10/02/2024] [Indexed: 10/12/2024]
Abstract
Climate change affects more than elsewhere the northern circumpolar permafrost region. This zone comprises large rivers flowing mainly to the Arctic Ocean, delivering about 10 % of the global riverine water flux. These pan-Arctic Rivers drive the dynamics of northern organic carbon (OC) and mercury (Hg) cycling. Permafrost degradation may release substantial amounts of OC and Hg, with potential regional and global impacts. In this review, we summarise the main findings in the last three decades about the role of the pan-Arctic Rivers in OC and Hg cycling and the effect of climate change on these dynamics. Total DOC and POC fluxes delivered by the pan-Arctic rivers presently reach 34.4 ± 1.2 TgC·yr-1 and 7.9 ± 0.5 TgC·yr-1, while the export of Hg reaches 38.9 ± 1.7 Mg·yr-1. This review highlights future challenges for the scientific community in evaluating spatial and temporal dynamics of the processes involved in OC and Hg cycling in permafrost-affected areas. Permafrost thawing could lead to greater fluxes of OC and Hg with ill-known resulting risks for food chains. Within this context, efforts should be made to study OC effects on Hg methylation. Moreover, assessing the spatial variability of OC and Hg mobilisation and transport within the pan-Arctic watersheds may help understand the future OC and Hg cycling dynamics in the northern circumpolar permafrost region.
Collapse
Affiliation(s)
- Clément Fabre
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; Laboratoire Ecologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, INPT, UPS, Avenue de l'Agrobiopole, 31326 Auzeville-Tolosane, France.
| | - Jeroen E Sonke
- Geosciences Environnement Toulouse, CNRS/IRD/CNES/Université Toulouse III, 14 avenue Edouard Belin, 31400 Toulouse, France
| | - Nikita Tananaev
- Melnikov Permafrost Institute, SB RAS, Yakutsk 677010, Russia
| | - Roman Teisserenc
- Laboratoire Ecologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, INPT, UPS, Avenue de l'Agrobiopole, 31326 Auzeville-Tolosane, France
| |
Collapse
|
2
|
Gillies EJ, Li ML, Christensen V, Hoover C, Sora KJ, Loseto LL, Cheung WWL, Angot H, Giang A. Exploring Drivers of Historic Mercury Trends in Beluga Whales Using an Ecosystem Modeling Approach. ACS ENVIRONMENTAL AU 2024; 4:219-235. [PMID: 39309976 PMCID: PMC11413906 DOI: 10.1021/acsenvironau.3c00072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 05/08/2024] [Accepted: 05/20/2024] [Indexed: 09/25/2024]
Abstract
While mercury occurs naturally in the environment, human activity has significantly disturbed its biogeochemical cycle. Inorganic mercury entering aquatic systems can be transformed into methylmercury, a strong neurotoxicant that builds up in organisms and affects ecosystem and public health. In the Arctic, top predators such as beluga whales, an ecologically and culturally significant species for many Inuit communities, can contain high concentrations of methylmercury. Historical mercury concentrations in beluga in the western Canadian Arctic's Beaufort Sea cannot be explained by mercury emission trends alone; in addition, they could potentially be driven by climate change impacts, such as rising temperatures and sea ice melt. These changes can affect mercury bioaccumulation through different pathways, including ecological and mercury transport processes. In this study, we explore key drivers of mercury bioaccumulation in the Beaufort Sea beluga population using Ecopath with Ecosim, an ecosystem modeling approach, and scenarios of environmental change informed by Western Science and Inuvialuit Knowledge. Comparing the effect of historical sea ice cover, sea surface temperature, and freshwater discharge time series, modeling suggests that the timing of historical increases and decreases in beluga methylmercury concentrations can be better explained by the resulting changes to ecosystem productivity rather than by those to mercury inputs and that all three environmental drivers could partially explain the decrease in mercury concentrations in beluga after the mid-1990s. This work highlights the value of multiple knowledge systems and exploratory modeling methods in understanding environmental change and contaminant cycling. Future work building on this research could inform climate change adaptation efforts and inform management decisions in the region.
Collapse
Affiliation(s)
- Emma J. Gillies
- Institute
for Resources, Environment and Sustainability, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Mi-Ling Li
- School
of Marine Science and Policy, University
of Delaware, Newark, Delaware 19716, United States
| | - Villy Christensen
- Institute
for the Oceans and Fisheries, University
of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Carie Hoover
- Marine
Affairs Program, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Freshwater
Institute, Fisheries and Oceans Canada, Winnipeg, MB R3T
2N6, Canada
| | - Kristen J. Sora
- Institute
for the Oceans and Fisheries, University
of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Lisa L. Loseto
- Freshwater
Institute, Fisheries and Oceans Canada, Winnipeg, MB R3T
2N6, Canada
- Centre
for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T
2N2, Canada
| | - William W. L. Cheung
- Institute
for the Oceans and Fisheries, University
of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Hélène Angot
- Univ. Grenoble
Alpes, CNRS, INRAE, IRD, Grenoble INP, IGE, Grenoble 38400, France
| | - Amanda Giang
- Institute
for Resources, Environment and Sustainability, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| |
Collapse
|
3
|
Wenwen Z, Yuan X, Zhongsheng Z, Xuehui Z, Haitao W. Accelerated Hg loss and increased methylmercury covary with soil organic matter mineralization and dissolved organic matter humification under warming conditions in permafrost marsh, Northeast China. ENVIRONMENTAL RESEARCH 2023; 234:116593. [PMID: 37423359 DOI: 10.1016/j.envres.2023.116593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/06/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Currently, little is available on how mercury (Hg) methylation couples with soil organic matter decomposition in degraded permafrost in high northern latitudes, where the climate is becoming warmer rapidly. Here, we revealed the complex interactions between soil organic matter (SOM) mineralization, dissolved organic matter (DOM) and methylmercury (MeHg) production based on an 87-day anoxic warming incubation experiment. Results supported remarkably promotion effects of warming on MeHg production, by 130%-205% on average. Total mercury (THg) loss under warming treatment depended on marsh types but showed an increasing trend on the whole. Warming yielded higher proportions of MeHg to THg (%MeHg), increased by 123%-569%. As expected, greenhouse gas emission was significantly enhanced by warming. Warming also strengthened fluorescence intensities of fulvic-like and protein-like DOM, with contributions to total fluorescence intensities of 49%-92% and 8%-51%, respectively. DOM and its spectral features explained 60% variation of MeHg, and the explanation increased to 82% in conjunction with greenhouse gas emissions. The structural equation model implied that warming, greenhouse gas emission, and humification of DOM had positive effects on Hg methylation potential, while microbial-derived DOM showed negative effects on MeHg. These results showed that accelerated Hg loss and increased methylation covaried with greenhouse gas emission and DOM formation under warming conditions in permafrost marsh.
Collapse
Affiliation(s)
- Zhao Wenwen
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin Yuan
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhang Zhongsheng
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
| | - Zhang Xuehui
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Beijing Normal University, Beijing, 136000, China
| | - Wu Haitao
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| |
Collapse
|
4
|
Xin Y, Zhang X, Zheng D, Zhang Z, Jiang M. Impacts of spectral characteristics of dissolved organic matter on methylmercury contents in peatlands, Northeast China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:913-923. [PMID: 35366716 DOI: 10.1007/s10653-022-01257-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Dissolved organic matter (DOM) plays an important role in promoting or suppressing methylmercury (MeHg) production in wetlands. However, the effects of DOM spectral characteristics on MeHg levels remain poorly understood in boreal peatlands in Northeast China, where is undergoing remarkable climate warming. In the present work, soil samples were collected from 22 peatlands in the Greater Khingan Mountains (GKM) to test the hypothesis that DOM spectral properties control MeHg levels. DOM was characterized by UV-Vis absorption and fluorescence spectroscopy; the three-dimensional fluorescence excitation-emission matrix (EEM) was used to unveil the origin of DOM. The average total mercury (THg) and MeHg contents were 112.76 µg/kg and 12.43 µg/kg across all peatlands, respectively. There was a significantly positive correlation between MeHg and the longitude spanning the range from 120 to 123°E (p < 0.05). Proportions of MeHg to THg (%MeHg), 12.3% on average, were positively correlated with DOM humification degree at p < 0.05 level. Protein-like components of DOM (P-like) were negatively related to %MeHg. DOM had positive effects on THg, and P-like components, HIX and BIX can negatively affect THg as well as MeHg. Our findings demonstrate that the spectral characteristics of DOM in soil are crucial to the content of methyl mercury in the GKM soil.
Collapse
Affiliation(s)
- Yuan Xin
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China
- Environmental College, Shenyang University, Shenyang, 110044, China
- Key Laboratory of Regional Environment and Eco-Remediation, Ministry of Education, Shenyang University, Shenyang, 110044, China
| | - Xuehui Zhang
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dongmei Zheng
- Environmental College, Shenyang University, Shenyang, 110044, China
- Key Laboratory of Regional Environment and Eco-Remediation, Ministry of Education, Shenyang University, Shenyang, 110044, China
| | - Zhongsheng Zhang
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China.
| | - Ming Jiang
- Institute of Northeast Geography and Agroecology, Chinese Academy of Science, No.4888, Shengbei Street, Kuancheng District, Changchun, 130102, China
| |
Collapse
|
5
|
Jonsson S, Mastromonaco MN, Wang F, Bravo AG, Cairns WRL, Chételat J, Douglas TA, Lescord G, Ukonmaanaho L, Heimbürger-Boavida LE. Arctic methylmercury cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157445. [PMID: 35882324 DOI: 10.1016/j.scitotenv.2022.157445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Anthropogenic mercury (Hg) undergoes long-range transport to the Arctic where some of it is transformed into methylmercury (MeHg), potentially leading to high exposure in some Arctic inhabitants and wildlife. The environmental exposure of Hg is determined not just by the amount of Hg entering the Arctic, but also by biogeochemical and ecological processes occurring in the Arctic. These processes affect MeHg uptake in biota by regulating the bioavailability, methylation and demethylation, bioaccumulation and biomagnification of MeHg in Arctic ecosystems. Here, we present a new budget for pools and fluxes of MeHg in the Arctic and review the scientific advances made in the last decade on processes leading to environmental exposure to Hg. Methylation and demethylation are key processes controlling the pool of MeHg available for bioaccumulation. Methylation of Hg occurs in diverse Arctic environments including permafrost, sediments and the ocean water column, and is primarily a process carried out by microorganisms. While microorganisms carrying the hgcAB gene pair (responsible for Hg methylation) have been identified in Arctic soils and thawing permafrost, the formation pathway of MeHg in oxic marine waters remains less clear. Hotspots for methylation of Hg in terrestrial environments include thermokarst wetlands, ponds and lakes. The shallow sub-surface enrichment of MeHg in the Arctic Ocean, in comparison to other marine systems, is a possible explanation for high MeHg concentrations in some Arctic biota. Bioconcentration of aqueous MeHg in bacteria and algae is a critical step in the transfer of Hg to top predators, which may be dampened or enhanced by the presence of organic matter. Variable trophic position has an important influence on MeHg concentrations among populations of top predator species such as ringed seal and polar bears distributed across the circumpolar Arctic. These scientific advances highlight key processes that affect the fate of anthropogenic Hg deposited to Arctic environments.
Collapse
Affiliation(s)
- Sofi Jonsson
- Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden.
| | | | - Feiyue Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
| | - Warren R L Cairns
- CNR Institute of Polar Sciences and Ca' Foscari University, Venice, Italy
| | - John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK, USA
| | - Gretchen Lescord
- Wildlife Conservation Society Canada and Laurentian University, Vale Living with Lakes Center, Sudbury, Ontario, Canada
| | - Liisa Ukonmaanaho
- Natural Resources Institute Finland (Luke), P.O. Box 2, FI-00791 Helsinki, Finland
| | - Lars-Eric Heimbürger-Boavida
- CNRS/INSU,Aix Marseille Université,Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France
| |
Collapse
|
6
|
Dastoor A, Wilson SJ, Travnikov O, Ryjkov A, Angot H, Christensen JH, Steenhuisen F, Muntean M. Arctic atmospheric mercury: Sources and changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156213. [PMID: 35623517 DOI: 10.1016/j.scitotenv.2022.156213] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Global anthropogenic and legacy mercury (Hg) emissions are the main sources of Arctic Hg contamination, primarily transported there via the atmosphere. This review summarizes the state of knowledge of the global anthropogenic sources of Hg emissions, and examines recent changes and source attribution of Hg transport and deposition to the Arctic using models. Estimated global anthropogenic Hg emissions to the atmosphere for 2015 were ~2220 Mg, ~20% higher than 2010. Global anthropogenic, legacy and geogenic Hg emissions were, respectively, responsible for 32%, 64% (wildfires: 6-10%) and 4% of the annual Arctic Hg deposition. Relative contributions to Arctic deposition of anthropogenic origin was dominated by sources in East Asia (32%), Commonwealth of Independent States (12%), and Africa (12%). Model results exhibit significant spatiotemporal variations in Arctic anthropogenic Hg deposition fluxes, driven by regional differences in Hg air transport routes, surface and precipitation uptake rates, and inter-seasonal differences in atmospheric circulation and deposition pathways. Model simulations reveal that changes in meteorology are having a profound impact on contemporary atmospheric Hg in the Arctic. Reversal of North Atlantic Oscillation phase from strongly negative in 2010 to positive in 2015, associated with lower temperature and more sea ice in the Canadian Arctic, Greenland and surrounding ocean, resulted in enhanced production of bromine species and Hg(0) oxidation and lower evasion of Hg(0) from ocean waters in 2015. This led to increased Hg(II) (and its deposition) and reduced Hg(0) air concentrations in these regions in line with High Arctic observations. However, combined changes in meteorology and anthropogenic emissions led to overall elevated modeled Arctic air Hg(0) levels in 2015 compared to 2010 contrary to observed declines at most monitoring sites, likely due to uncertainties in anthropogenic emission speciation, wildfire emissions and model representations of air-surface Hg fluxes.
Collapse
Affiliation(s)
- Ashu Dastoor
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans-Canada Highway, Dorval, Québec H9P 1J3, Canada.
| | - Simon J Wilson
- Arctic Monitoring and Assessment Programme (AMAP). The Fram Centre, Box 6606 Stakkevollan, 9296 Tromsø, Norway.
| | - Oleg Travnikov
- Meteorological Synthesizing Centre-East, EMEP, 2nd Roshchinsky proezd, 8/5, 115419 Moscow, Russia
| | - Andrei Ryjkov
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans-Canada Highway, Dorval, Québec H9P 1J3, Canada
| | - Hélène Angot
- Extreme Environments Research Laboratory, École Polytechnique Fédérale de Lausanne (EPFL) Valais Wallis, Sion, Switzerland
| | - Jesper H Christensen
- Department of Environmental Science, iClimate, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Frits Steenhuisen
- Arctic Centre, University of Groningen, Aweg 30, 9718CW Groningen, the Netherlands
| | - Marilena Muntean
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749 (T.P. 123), I-21027 Ispra, VA, Italy
| |
Collapse
|
7
|
Chételat J, McKinney MA, Amyot M, Dastoor A, Douglas TA, Heimbürger-Boavida LE, Kirk J, Kahilainen KK, Outridge PM, Pelletier N, Skov H, St Pierre K, Vuorenmaa J, Wang F. Climate change and mercury in the Arctic: Abiotic interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153715. [PMID: 35149079 DOI: 10.1016/j.scitotenv.2022.153715] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Dramatic environmental shifts are occuring throughout the Arctic from climate change, with consequences for the cycling of mercury (Hg). This review summarizes the latest science on how climate change is influencing Hg transport and biogeochemical cycling in Arctic terrestrial, freshwater and marine ecosystems. As environmental changes in the Arctic continue to accelerate, a clearer picture is emerging of the profound shifts in the climate and cryosphere, and their connections to Hg cycling. Modeling results suggest climate influences seasonal and interannual variability of atmospheric Hg deposition. The clearest evidence of current climate change effects is for Hg transport from terrestrial catchments, where widespread permafrost thaw, glacier melt and coastal erosion are increasing the export of Hg to downstream environments. Recent estimates suggest Arctic permafrost is a large global reservoir of Hg, which is vulnerable to degradation with climate warming, although the fate of permafrost soil Hg is unclear. The increasing development of thermokarst features, the formation and expansion of thaw lakes, and increased soil erosion in terrestrial landscapes are increasing river transport of particulate-bound Hg and altering conditions for aquatic Hg transformations. Greater organic matter transport may also be influencing the downstream transport and fate of Hg. More severe and frequent wildfires within the Arctic and across boreal regions may be contributing to the atmospheric pool of Hg. Climate change influences on Hg biogeochemical cycling remain poorly understood. Seasonal evasion and retention of inorganic Hg may be altered by reduced sea-ice cover and higher chloride content in snow. Experimental evidence indicates warmer temperatures enhance methylmercury production in ocean and lake sediments as well as in tundra soils. Improved geographic coverage of measurements and modeling approaches are needed to better evaluate net effects of climate change and long-term implications for Hg contamination in the Arctic.
Collapse
Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, National Wildlife Research Centre, Ottawa, ON K1A 0H3, Canada.
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Marc Amyot
- Groupe de recherche interuniversitaire en limnologie (GRIL), Département de sciences biologiques, Complexe des Sciences, Montréal, QC H2V 0B3, Canada
| | - Ashu Dastoor
- Environment and Climate Change Canada, Air Quality Research Division, Dorval, QC H9P 1J3, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK 99709, USA
| | - Lars-Eric Heimbürger-Boavida
- Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Marseille, France
| | - Jane Kirk
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Burlington, ON L7S 1A1, Canada
| | - Kimmo K Kahilainen
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, FI-16900 Lammi, Finland
| | - Peter M Outridge
- Geological Survey of Canada, Natural Resources Canada, Ottawa, ON K1A 0E8, Canada
| | - Nicolas Pelletier
- Geography and Environmental Studies, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Henrik Skov
- Department of Environmental Science, iClimate, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Kyra St Pierre
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jussi Vuorenmaa
- Finnish Environment Institute (SYKE), Latokartanonkaari 11, FI-00790 Helsinki, Finland
| | - Feiyue Wang
- Centre for Earth Observation Sciences (CEOS), Dept. of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
8
|
Zhang L, Philben M, Taş N, Johs A, Yang Z, Wullschleger SD, Graham DE, Pierce EM, Gu B. Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 299:118878. [PMID: 35085651 DOI: 10.1016/j.envpol.2022.118878] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Arctic tundra soils store a globally significant amount of mercury (Hg), which could be transformed to the neurotoxic methylmercury (MeHg) upon warming and thus poses serious threats to the Arctic ecosystem. However, our knowledge of the biogeochemical drivers of MeHg production is limited in these soils. Using substrate addition (acetate and sulfate) and selective microbial inhibition approaches, we investigated the geochemical drivers and dominant microbial methylators in 60-day microcosm incubations with two tundra soils: a circumneutral fen soil and an acidic bog soil, collected near Nome, Alaska, United States. Results showed that increasing acetate concentration had negligible influences on MeHg production in both soils. However, inhibition of sulfate-reducing bacteria (SRB) completely stalled MeHg production in the fen soil in the first 15 days, whereas addition of sulfate in the low-sulfate bog soil increased MeHg production by 5-fold, suggesting prominent roles of SRB in Hg(II) methylation. Without the addition of sulfate in the bog soil or when sulfate was depleted in the fen soil (after 15 days), both SRB and methanogens contributed to MeHg production. Analysis of microbial community composition confirmed the presence of several phyla known to harbor microorganisms associated with Hg(II) methylation in the soils. The observations suggest that SRB and methanogens were mainly responsible for Hg(II) methylation in these tundra soils, although their relative contributions depended on the availability of sulfate and possibly syntrophic metabolisms between SRB and methanogens.
Collapse
Affiliation(s)
- Lijie Zhang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA; Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Michael Philben
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Neslihan Taş
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, USA
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, MI, 48309, USA
| | - Stan D Wullschleger
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - David E Graham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Eric M Pierce
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| |
Collapse
|
9
|
Matsuyama A, Yano S, Taniguchi Y, Kindaichi M, Tada A, Wada M. Trends in mercury concentrations and methylation in Minamata Bay, Japan, between 2014 and 2018. MARINE POLLUTION BULLETIN 2021; 173:112886. [PMID: 34571383 DOI: 10.1016/j.marpolbul.2021.112886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/21/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Methylmercury concentrations in Minamata Bay are high, but the cause is unclear. We conducted a basic study on the behavior of methylmercury in Minamata Bay seawater; the findings suggest that mercury methylation may occur throughout the year in Minamata Bay. Seawater temperature, salinity, and concentrations of dissolved organic carbon were the environmental factors that affected methylation, and the degree of methylation was closely related to bacterial community structure. The concentration of methylmercury in suspended particulate matter was highest 10 m below the surface and decreased with greater depths. We did not observe a correlation between methylmercury concentrations in suspended particulate matter and concentrations of dissolved methylmercury.
Collapse
Affiliation(s)
- Akito Matsuyama
- Department of International Affairs and Research, National Institute for Minamata Disease (NIMD), 4058-18 Hama, Minamata, Kumamoto 867-0008, Japan.
| | - Shinichiro Yano
- Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Yoko Taniguchi
- Department of International Affairs and Research, National Institute for Minamata Disease (NIMD), 4058-18 Hama, Minamata, Kumamoto 867-0008, Japan.
| | - Michiaki Kindaichi
- Department of International Affairs and Research, National Institute for Minamata Disease (NIMD), 4058-18 Hama, Minamata, Kumamoto 867-0008, Japan.
| | - Akihide Tada
- Faculty of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
| | - Minoru Wada
- Faculty of Fisheries, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
| |
Collapse
|
10
|
Malcata Martins B, O'Driscoll NJ, Mallory ML, Canário J. A Review of Freshwater Invertebrates as Biomonitors of Methylmercury: the Importance of More Complete Physical and Chemical Reporting. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 107:801-808. [PMID: 34081149 DOI: 10.1007/s00128-021-03274-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
Methylmercury (MeHg) is a toxic and bioaccumulative organo-metallic compound that is naturally produced in many ecosystems. Organisms that occupy the lower trophic positions in food webs may be key factors in the assessment of MeHg biomagnification between ecosystems. Here we present a review of the peer-reviewed literature examining MeHg bioaccumulation in freshwater invertebrates, focused principally on insects. This review aims to characterize the invertebrates that bioaccumulate higher MeHg concentrations and therefore pose a higher risk to upper trophic levels and to clarify which ecosystems are more susceptible to bioaccumulation in lower trophic levels. However, we found that few studies provided robust environmental data (notably water chemistry) as part of their papers, dramatically limiting our ability to test for factors that might contribute to different concentrations of MeHg in invertebrates. We highlight the importance of providing physical and chemical characteristics of study sites in publications examining MeHg bioaccumulation and biomagnification. Adopting the proposed recommendations will improve the available information for future mercury risk assessment analyses.
Collapse
Affiliation(s)
- Beatriz Malcata Martins
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisboa, Portugal.
| | - Nelson J O'Driscoll
- Department of Earth and Environmental Science, K.C. Irving Environmental Science Center, Acadia University, Wolfville, NS, B4P 2R6, Canada
| | - Mark L Mallory
- Department of Biology, Acadia University, Wolfville, NS, B4P 2R6, Canada
| | - João Canário
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisboa, Portugal
| |
Collapse
|
11
|
Tarbier B, Hugelius G, Kristina Sannel AB, Baptista-Salazar C, Jonsson S. Permafrost Thaw Increases Methylmercury Formation in Subarctic Fennoscandia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6710-6717. [PMID: 33902281 PMCID: PMC8277125 DOI: 10.1021/acs.est.0c04108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 04/13/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
Methylmercury (MeHg) forms in anoxic environments and can bioaccumulate and biomagnify in aquatic food webs to concentrations of concern for human and wildlife health. Mercury (Hg) pollution in the Arctic environment may worsen as these areas warm and Hg, currently locked in permafrost soils, is remobilized. One of the main concerns is the development of Hg methylation hotspots in the terrestrial environment due to thermokarst formation. The extent to which net methylation of Hg is enhanced upon thaw is, however, largely unknown. Here, we have studied the formation of Hg methylation hotspots using existing thaw gradients at five Fennoscandian permafrost peatland sites. Total Hg (HgT) and MeHg concentrations were analyzed in 178 soil samples from 14 peat cores. We observed 10 times higher concentrations of MeHg and 13 times higher %MeHg in the collapse fen (representing thawed conditions) as compared to the peat plateau (representing frozen conditions). This suggests significantly greater net methylation of Hg when thermokarst wetlands are formed. In addition, we report HgT to soil organic carbon ratios representative of Fennoscandian permafrost peatlands (median and interquartile range of 0.09 ± 0.07 μg HgT g-1 C) that are of value for future estimates of circumpolar HgT stocks.
Collapse
Affiliation(s)
- Brittany Tarbier
- Department
of Physical Geography, Stockholm University, Stockholm 106 91, Sweden
| | - Gustaf Hugelius
- Department
of Physical Geography, Stockholm University, Stockholm 106 91, Sweden
- Bolin
Centre for Climate Research, Stockholm University, Stockholm 106 91, Sweden
| | - Anna Britta Kristina Sannel
- Department
of Physical Geography, Stockholm University, Stockholm 106 91, Sweden
- Bolin
Centre for Climate Research, Stockholm University, Stockholm 106 91, Sweden
| | | | - Sofi Jonsson
- Department
of Environmental Science, Stockholm University, Stockholm 106 91, Sweden
| |
Collapse
|
12
|
Varty S, Lehnherr I, St Pierre K, Kirk J, Wisniewski V. Methylmercury Transport and Fate Shows Strong Seasonal and Spatial Variability along a High Arctic Freshwater Hydrologic Continuum. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:331-340. [PMID: 33356178 DOI: 10.1021/acs.est.0c05051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The presence of toxic methylmercury (MeHg) in Arctic freshwater ecosystems and foodwebs is a potential health concern for northern Indigenous people. Addressing this issue requires a better understanding of MeHg production, fate during transport, and uptake into foodwebs. We used methylation assays and spatiotemporal surveys of MeHg concentrations, during the ice-covered and open water seasons, across a hydrologic continuum (composed of thaw seeps, lake/ponds, and a wetland) to identify Hg methylation hotspots and seasonal differences in MeHg cycling unique to Arctic ecosystems. Ponds and saturated wetland soils support methylation hotspots during the open water season, but subsequent export of MeHg to downstream ecosystems is limited by particle settling, binding of MeHg on soil organic matter, and/or demethylation in drier wetland soils. During the ice-covered season, MeHg concentrations in lake waters were approximately ten-fold greater than in summer; however, zooplankton MeHg concentrations were paradoxically five times lower at this time. Despite limited evidence of snow-phase methylation, the snowpack is an important MeHg reservoir. Changes in ice-cover duration will alter MeHg production and bioaccumulation in lakes, while increased thaw and surface water flow will likely result in higher methylation rates at the aquatic-terrestrial interface and more efficient downstream transport of MeHg.
Collapse
Affiliation(s)
- Stephanie Varty
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Igor Lehnherr
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Kyra St Pierre
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - Jane Kirk
- Canada Centre for Inland Waters, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Victoria Wisniewski
- Department of Geography, Geomatics and Environment, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| |
Collapse
|
13
|
Liu J, Wang D, Zhang J, Liem-Nguyen V, Huang R, Jiang T. Evaluation of Hg methylation in the water-level-fluctuation zone of the Three Gorges Reservoir region by using the MeHg/Hg T ratio. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 195:110468. [PMID: 32200146 DOI: 10.1016/j.ecoenv.2020.110468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/05/2020] [Accepted: 03/09/2020] [Indexed: 06/10/2023]
Abstract
In the recent decade, the hydroelectric reservoir is identified as a methylmercury (MeHg) hotspot and gained much attention. The artificial water level management in the Three Gorges Reservoir (TGR) in China formed a water-level-fluctuation zone (WLFZ) undergoing flooding drying rotations annually. However, the mercury (Hg) methylation and major geochemical driving factors at different elevations in the WLFZ remain unclear. Here we use total Hg (HgT) normalized MeHg (MeHg/HgT ratio) to evaluate Hg methylation degree in a one-year field study at 155, 165 m elevations in the WLFZ and with >175 m elevation as the reference. Results demonstrate that MeHg/HgT ratio at the WLFZ could reach 4.1% in soils, and both 155 and 165 m elevations have a higher Hg methylation degree than the >175 m elevation. However, the differences in MeHg/HgT ratios both in soils and waters between 155 and 165 m elevations are not significant. This indicates the influence of different submerging periods on the MeHg/HgT at the WLFZ elevations is not observed. The significant correlation between the MeHg/HgT ratio and soil organic carbon (SOC) content implies a MeHg retention in re-exposed soils after flooding. Decoupling of MeHg/HgT ratios between submerged soil and overlying water are found at both elevations and therefore make MeHg/HgT in waters alone cannot be used to evaluate Hg methylation degree in this study. The calculation of HgT and MeHg partitioning coefficient (Kd) found an immobilization of MeHg by submerged soils at the WLFZ during the flooding period. Major geochemical factors, determined through principal component analysis (PCA), in affecting Hg methylation are the redox cycling of sulfur and the distribution of organic matters in the WLFZ.
Collapse
Affiliation(s)
- Jiang Liu
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China; Centre for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| | - Dingyong Wang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China.
| | - Jinzhong Zhang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China.
| | - Van Liem-Nguyen
- Laboratory of Advanced Materials Chemistry, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
| | - Rong Huang
- College of Resources, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Tao Jiang
- Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China.
| |
Collapse
|
14
|
Ci Z, Peng F, Xue X, Zhang X. Permafrost Thaw Dominates Mercury Emission in Tibetan Thermokarst Ponds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:5456-5466. [PMID: 32294379 DOI: 10.1021/acs.est.9b06712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Increasing evidence shows that warming is driving Hg release from the cryosphere. However, Hg cycling in thawing permafrost is less understood to date. Here we show that permafrost thaw dominantly supplied no-run thermokarst ponds by permafrost melt waters (PMWs) with high concentration of photoreducible Hg (PRHg) and subsequently controlled Hg(0) emissions in the Tibetan Plateau. This study was motivated by field survey suggesting that thermokarst ponds as recipient aquatic systems of PMWs could be an active converter of PRHg to Hg(0). Annual Hg mass balance in three seasonally ice-covered thermokarst ponds suggests that PMWs were the dominant input (81.2% to 91.2%) of PRHg in all three thermokarst ponds, and PRHg input would be a constraint of Hg(0) emission owing to the fast photoreduction of PRHg to Hg(0) in the water column. Annual Hg(0) emission in the thermokarst ponds of study region was conservatively estimated to increase by 15% over the past half century. Our findings highlight that climate-induced landscape disturbances and changes in hydrogeochemical processes in climate-sensitive permafrost will quickly and in situ drive Hg stored in permafrost for a very long time into the modern day Hg cycle, which potentially offsets the anthropogenic Hg mitigation policies.
Collapse
Affiliation(s)
- Zhijia Ci
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Fei Peng
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
- International Platform for Dryland Research and Education, Tottori University, Tottori 680-0001, Japan
| | - Xian Xue
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
| | - Xiaoshan Zhang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| |
Collapse
|
15
|
Bravo AG, Cosio C. Biotic formation of methylmercury: A bio-physico-chemical conundrum. LIMNOLOGY AND OCEANOGRAPHY 2020; 65:1010-1027. [PMID: 32612306 PMCID: PMC7319479 DOI: 10.1002/lno.11366] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/17/2019] [Accepted: 10/02/2019] [Indexed: 05/11/2023]
Abstract
Mercury (Hg) is a natural and widespread trace metal, but is considered a priority pollutant, particularly its organic form methylmercury (MMHg), because of human's exposure to MMHg through fish consumption. Pioneering studies showed the methylation of divalent Hg (HgII) to MMHg to occur under oxygen-limited conditions and to depend on the activity of anaerobic microorganisms. Recent studies identified the hgcAB gene cluster in microorganisms with the capacity to methylate HgII and unveiled a much wider range of species and environmental conditions producing MMHg than previously expected. Here, we review the recent knowledge and approaches used to understand HgII-methylation, microbial biodiversity and activity involved in these processes, and we highlight the current limits for predicting MMHg concentrations in the environment. The available data unveil the fact that HgII methylation is a bio-physico-chemical conundrum in which the efficiency of biological HgII methylation appears to depend chiefly on HgII and nutrients availability, the abundance of electron acceptors such as sulfate or iron, the abundance and composition of organic matter as well as the activity and structure of the microbial community. An increased knowledge of the relationship between microbial community composition, physico-chemical conditions, MMHg production, and demethylation is necessary to predict variability in MMHg concentrations across environments.
Collapse
Affiliation(s)
- Andrea G. Bravo
- Department of Marine Biology and Oceanography, Institute of Marine SciencesSpanish National Research Council (CSIC)BarcelonaSpain
| | - Claudia Cosio
- Université de Reims Champagne Ardennes, UMR‐I 02 INERIS‐URCA‐ULH SEBIO, Unité Stress Environnementaux et BIOsurveillance des milieux aquatiquesReimsFrance
| |
Collapse
|
16
|
Zolkos S, Krabbenhoft DP, Suslova A, Tank SE, McClelland JW, Spencer RGM, Shiklomanov A, Zhulidov AV, Gurtovaya T, Zimov N, Zimov S, Mutter EA, Kutny L, Amos E, Holmes RM. Mercury Export from Arctic Great Rivers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4140-4148. [PMID: 32122125 DOI: 10.1021/acs.est.9b07145] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Land-ocean linkages are strong across the circumpolar north, where the Arctic Ocean accounts for 1% of the global ocean volume and receives more than 10% of the global river discharge. Yet estimates of Arctic riverine mercury (Hg) export constrained from direct Hg measurements remain sparse. Here, we report results from a coordinated, year-round sampling program that focused on the six major Arctic rivers to establish a contemporary (2012-2017) benchmark of riverine Hg export. We determine that the six major Arctic rivers exported an average of 20 000 kg y-1 of total Hg (THg, all forms of Hg). Upscaled to the pan-Arctic, we estimate THg flux of 37 000 kg y-1. More than 90% of THg flux occurred during peak river discharge in spring and summer. Normalizing fluxes to watershed area (yield) reveals higher THg yields in regions where greater denudation likely enhances Hg mobilization. River discharge, suspended sediment, and dissolved organic carbon predicted THg concentration with moderate fidelity, while suspended sediment and water yields predicted THg yield with high fidelity. These findings establish a benchmark in the face of rapid Arctic warming and an intensifying hydrologic cycle, which will likely accelerate Hg cycling in tandem with changing inputs from thawing permafrost and industrial activity.
Collapse
Affiliation(s)
- Scott Zolkos
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - David P Krabbenhoft
- Upper Midwest Water Science Center, Mercury Research Laboratory, United States Geological Survey, Middleton, Wisconsin 53562, United States
| | - Anya Suslova
- Woods Hole Research Center, Woods Hole, Massachusetts 02540, United States
| | - Suzanne E Tank
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - James W McClelland
- Marine Science Institute, University of Texas at Austin, Port Aransas, Texas 78373, United States
| | - Robert G M Spencer
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Alexander Shiklomanov
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Alexander V Zhulidov
- South Russia Centre for Preparation and Implementation of International Projects, Rostov-on-Don 344090, Russia
| | - Tatiana Gurtovaya
- South Russia Centre for Preparation and Implementation of International Projects, Rostov-on-Don 344090, Russia
| | - Nikita Zimov
- Northeast Science Station, Far Eastern Branch of Russian Academy of Science, Chersky 690041, Russia
| | - Sergey Zimov
- Northeast Science Station, Far Eastern Branch of Russian Academy of Science, Chersky 690041, Russia
| | - Edda A Mutter
- Yukon River Inter-Tribal Watershed Council, Anchorage, Alaska 99501, United States
| | - Les Kutny
- Les Kutny Consultant, Inuvik, Northwest Territories X0E 0T0, Canada
| | - Edwin Amos
- Western Arctic Research Centre, Inuvik, Northwest Territories X0E 0T0, Canada
| | - Robert M Holmes
- Woods Hole Research Center, Woods Hole, Massachusetts 02540, United States
| |
Collapse
|
17
|
Hudelson KE, Muir DCG, Drevnick PE, Köck G, Iqaluk D, Wang X, Kirk JL, Barst BD, Grgicak-Mannion A, Shearon R, Fisk AT. Temporal trends, lake-to-lake variation, and climate effects on Arctic char (Salvelinus alpinus) mercury concentrations from six High Arctic lakes in Nunavut, Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 678:801-812. [PMID: 31085496 DOI: 10.1016/j.scitotenv.2019.04.453] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
Climate warming and mercury (Hg) are concurrently influencing Arctic ecosystems, altering their functioning and threatening food security. Non-anadromous Arctic char (Salvelinus alpinus) in small lakes were used to biomonitor these two anthropogenic stressors, because this iconic Arctic species is a long-lived top predator in relatively simple food webs, and yet population characteristics vary greatly, reflecting differences between lake systems. Mercury concentrations in six landlocked Arctic char populations on Cornwallis Island, Nunavut have been monitored as early as 1989, providing a novel dataset to examine differences in muscle [Hg] among char populations, temporal trends, and the relationship between climate patterns and Arctic char [Hg]. We found significant lake-to-lake differences in length-adjusted Arctic char muscle [Hg], which varied by up to 9-fold. Arctic char muscle [Hg] was significantly correlated to dissolved and particulate organic carbon concentrations in water; neither watershed area or vegetation cover explained differences. Three lakes exhibited significant temporal declines in length-adjusted [Hg] in Arctic char; the other three lakes had no significant trends. Though precipitation, temperature, wind speed, and sea ice duration were tested, no single climate variable was significantly correlated to length-adjusted [Hg] across populations. However, Arctic char Hg in Resolute Lake exhibited a significant correlation with sea ice duration, which is likely closely linked to lake ice duration, and which may impact Hg processing in lakes. Additionally, Arctic char [Hg] in Amituk Lake was significantly correlated to snow fall, which may be linked to Hg deposition. The lack of consistent temporal trends in neighboring char populations indicates that currently, within lake processes are the strongest drivers of [Hg] in char in the study lakes and potentially in other Arctic lakes, and that the influence of climate change will likely vary from lake to lake.
Collapse
Affiliation(s)
- Karista E Hudelson
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada; Centre Eau Terre Environnement, Institut National de la Recherche Scientifique, Université du Québec, Québec, QC G1K 9A9, Canada.
| | - Derek C G Muir
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON L7S 1A1, Canada.
| | - Paul E Drevnick
- Centre Eau Terre Environnement, Institut National de la Recherche Scientifique, Université du Québec, Québec, QC G1K 9A9, Canada; Alberta Environment and Parks, Environmental Monitoring and Science Division, Calgary, AB T2E 7L7, Canada
| | - Günter Köck
- Institute for Interdisciplinary Mountain Research, 6020 Innsbruck, Austria
| | - Deborah Iqaluk
- Hamlet of Resolute Bay, Resolute Bay, NU X0A 0V0, Canada
| | - Xiaowa Wang
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON L7S 1A1, Canada
| | - Jane L Kirk
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, ON L7S 1A1, Canada
| | - Benjamin D Barst
- Centre Eau Terre Environnement, Institut National de la Recherche Scientifique, Université du Québec, Québec, QC G1K 9A9, Canada; Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Alice Grgicak-Mannion
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Rebecca Shearon
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Aaron T Fisk
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada
| |
Collapse
|
18
|
St Pierre KA, Zolkos S, Shakil S, Tank SE, St Louis VL, Kokelj SV. Unprecedented Increases in Total and Methyl Mercury Concentrations Downstream of Retrogressive Thaw Slumps in the Western Canadian Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:14099-14109. [PMID: 30474969 DOI: 10.1021/acs.est.8b05348] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Retrogressive thaw slumps (RTSs) are thermokarst features created by the rapid thaw of ice-rich permafrost, and can mobilize vast quantities of sediments and solutes downstream. However, the effect of slumping on downstream concentrations and yields of total mercury (THg) and methylmercury (MeHg) is unknown. Fluvial concentrations of THg and MeHg downstream of RTSs on the Peel Plateau (Northwest Territories, Canada) were up to 2 orders of magnitude higher than upstream, reaching concentrations of 1,270 ng L-1 and 7 ng L-1, respectively, the highest ever measured in uncontaminated sites in Canada. MeHg concentrations were particularly elevated at sites downstream of RTSs where debris tongues dammed streams to form reservoirs where microbial Hg methylation was likely enhanced. However, > 95% of the Hg downstream was typically particle-bound and potentially not readily bioavailable. Mean open-water season yields of THg (610 mg km-2 d-1) and MeHg (2.61 mg km-2 d-1) downstream of RTSs were up to an order of magnitude higher than those for the nearby large Yukon, Mackenzie and Peel rivers. We estimate that ∼5% of the Hg stored for centuries or millennia in northern permafrost soils (88 Gg) is susceptible to release into modern-day Hg biogeochemical cycling from further climate changes and thermokarst formation.
Collapse
Affiliation(s)
- Kyra A St Pierre
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Scott Zolkos
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Sarah Shakil
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Suzanne E Tank
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Vincent L St Louis
- Department of Biological Sciences , University of Alberta , Edmonton , Alberta T6G 2E3 , Canada
| | - Steven V Kokelj
- Northwest Territories Geological Survey , Yellowknife , Northwest Territories X1A 2L9 , Canada
| |
Collapse
|
19
|
Emmerton CA, Cooke CA, Wentworth GR, Graydon JA, Ryjkov A, Dastoor A. Total Mercury and Methylmercury in Lake Water of Canada's Oil Sands Region. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10946-10955. [PMID: 30229653 DOI: 10.1021/acs.est.8b01680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Increased delivery of mercury to ecosystems is a common consequence of industrialization, including in the Athabasca Oil Sands Region (AOSR) of Canada. Atmospheric mercury deposition has been studied previously in the AOSR; however, less is known about the impact of regional industry on toxic methylmercury (MeHg) concentrations in lake ecosystems. We measured total mercury (THg) and MeHg concentrations for five years from 50 lakes throughout the AOSR. Mean lake water concentrations of THg (0.4-5.3 ng L-1) and MeHg (0.01-0.34 ng L-1) were similar to those of other boreal lakes and <5% of all samples exceeded Provincial water quality guidelines. Lakes with the highest THg concentrations were found >100 km northwest of oil sands mines and received runoff from geological formations high in metals concentrations. MeHg concentrations were highest in those lakes, and in smaller productive lakes closer to oil sands mines. Simulated annual average direct deposition of THg to sampled lakes using an atmospheric chemical transport model showed <2% of all mercury deposited to sampled lakes was emitted from oil sands activities. Consequently, spatial patterns of mercury in AOSR lakes were likely most influenced by watershed and lake conditions, though mercury concentrations in these lakes may be perturbed with future development and climatic change.
Collapse
Affiliation(s)
- Craig A Emmerton
- Environmental Monitoring and Science Division , Alberta Environment and Parks , Edmonton , Alberta T5J 5C6, Canada
| | - Colin A Cooke
- Environmental Monitoring and Science Division , Alberta Environment and Parks , Edmonton , Alberta T5J 5C6, Canada
| | - Gregory R Wentworth
- Environmental Monitoring and Science Division , Alberta Environment and Parks , Edmonton , Alberta T5J 5C6, Canada
| | | | - Andrei Ryjkov
- Air Quality Research Division , Environment and Climate Change Canada , Dorval , Quebec H9P 1J3, Canada
| | - Ashu Dastoor
- Air Quality Research Division , Environment and Climate Change Canada , Dorval , Quebec H9P 1J3, Canada
| |
Collapse
|
20
|
Góngora E, Braune BM, Elliott KH. Nitrogen and sulfur isotopes predict variation in mercury levels in Arctic seabird prey. MARINE POLLUTION BULLETIN 2018; 135:907-914. [PMID: 30301115 DOI: 10.1016/j.marpolbul.2018.07.075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 07/19/2018] [Accepted: 07/28/2018] [Indexed: 06/08/2023]
Abstract
Mercury (Hg) biotransformation and biomagnification are processes that affect Hg burdens in wildlife. To interpret variation in Hg in seabird eggs, used as Hg bioindicators in the Arctic, it is important to understand how Hg biomagnifies through the food web. We evaluated the use of δ34S, along with other commonly used stable isotope signatures (δ15N and δ13C), for the determination of possible sources of Hg in an Arctic food web (56 individuals of 15 species of fish and invertebrates). Hg correlated with δ34S (R2 = 0.72). When the combined effects of δ34S and δ15N were considered in mixed-effects models, both δ34S and δ15N together described Hg patterns in Arctic food webs better than either isotope alone. Our results demonstrate the usefulness of δ34S to account for variation in Hg among marine animals and to study the possible underlying effects that MeHg production may have on Hg pathways in Arctic ecosystems.
Collapse
Affiliation(s)
- Esteban Góngora
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue H9X 3V9, Canada.
| | - Birgit M Braune
- Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa K1A 0H3, Canada
| | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue H9X 3V9, Canada
| |
Collapse
|
21
|
Pokrovsky OS, Bueno M, Manasypov RM, Shirokova LS, Karlsson J, Amouroux D. Dissolved Organic Matter Controls Seasonal and Spatial Selenium Concentration Variability in Thaw Lakes across a Permafrost Gradient. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10254-10262. [PMID: 30148609 DOI: 10.1021/acs.est.8b00918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Little is known about the sources and processing of selenium, an important toxicant and essential micronutrient, within boreal and sub-arctic environments. Upon climate warming and permafrost thaw, the behavior of Se in northern peatlands becomes an issue of major concern, because a sizable amount of Se can be emitted to the atmosphere from thawing soils and inland water surfaces and exported to downstream waters, thus impacting the Arctic biota. Working toward providing a first-order assessment of spatial and temporal variation of Se concentration in thermokarst waters of the largest frozen peatland in the world, we sampled thaw lakes and rivers across a 750-km latitudinal profile. This profile covered sporadic, discontinuous, and continuous permafrost regions of western Siberia Lowland (WSL), where we measured dissolved (<0.45 μm) Se concentration during spring (June), summer (August), and autumn (September). We found maximum Se concentration in the discontinuous permafrost zone. Considering all sampled lakes, Se exhibited linear relationship ( R2 = 0.7 to 0.9, p < 0.05, n ≈ 70) with dissolved organic carbon (DOC) concentration during summer and autumn. Across the permafrost gradient, the lakes in discontinuous permafrost regions demonstrated stronger relationship with DOC and UV-absorbance compared to lakes in sporadic/isolated and continuous permafrost zones. Both seasonal and spatial features of Se distribution in thermokarst lakes and ponds suggest that Se is mainly released during thawing of frozen peat. Mobilization and immobilization of Se within peat-lake-river watersheds likely occurs as organic and organo-Fe, Al colloids, probably associated with reduced and elemental Se forms. The increase of active layer thickness may enhance leaching of Se in the form of organic complexes with aromatic carbon from the deep horizons of the peat profile. Further, the northward shift of permafrost boundaries in WSL may sizably increase Se concentration in lakes of continuous permafrost zone.
Collapse
Affiliation(s)
- Oleg S Pokrovsky
- Geoscience and Environment Toulouse, UMR 5563 CNRS , University of Toulouse , 31400 Toulouse , France
| | - Maite Bueno
- CNRS/UNIV PAU & PAYS ADOUR , Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR5254 , 64000 , Pau , France
| | - Rinat M Manasypov
- N. Laverov Federal Center for Integrated Arctic Research, IEPS , Russian Academy of Science , 16300 Arkhangelsk , Russia
- BIO-GEO-CLIM Laboratory , Tomsk State University , 634050 Tomsk , Russia
| | - Liudmila S Shirokova
- Geoscience and Environment Toulouse, UMR 5563 CNRS , University of Toulouse , 31400 Toulouse , France
- N. Laverov Federal Center for Integrated Arctic Research, IEPS , Russian Academy of Science , 16300 Arkhangelsk , Russia
| | - Jan Karlsson
- Climate Impacts Research Centre (CIRC), Department of Ecology and Environmental Science , Umeå University , 901 87 Umeå , Sweden
| | - David Amouroux
- CNRS/UNIV PAU & PAYS ADOUR , Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR5254 , 64000 , Pau , France
| |
Collapse
|
22
|
Ci Z, Peng F, Xue X, Zhang X. Temperature sensitivity of gaseous elemental mercury in the active layer of the Qinghai-Tibet Plateau permafrost. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 238:508-515. [PMID: 29605610 DOI: 10.1016/j.envpol.2018.02.085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 02/21/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
Soils represent the single largest mercury (Hg) reservoir in the global environment, indicating that a tiny change of Hg behavior in soil ecosystem could greatly affect the global Hg cycle. Climate warming is strongly altering the structure and functions of permafrost and then would influence the Hg cycle in permafrost soils. However, Hg biogeochemistry in climate-sensitive permafrost is poorly investigated. Here we report a data set of soil Hg (0) concentrations in four different depths of the active layer in the Qinghai-Tibet Plateau permafrost. We find that soil Hg (0) concentrations exhibited a strongly positive and exponential relationship with temperature and showed different temperature sensitivity under the frozen and unfrozen condition. We conservatively estimate that temperature increases following latest temperature scenarios of the IPCC could result in up to a 54.9% increase in Hg (0) concentrations in surface permafrost soils by 2100. Combining the simultaneous measurement of air-soil Hg (0) exchange, we find that enhanced Hg (0) concentrations in upper soils could favor Hg (0) emissions from surface soil. Our findings indicate that Hg (0) emission could be stimulated by permafrost thawing in a warmer world.
Collapse
Affiliation(s)
- Zhijia Ci
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Fei Peng
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Xian Xue
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Xiaoshan Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| |
Collapse
|
23
|
Wu P, Bishop K, von Brömssen C, Eklöf K, Futter M, Hultberg H, Martin J, Åkerblom S. Does forest harvest increase the mercury concentrations in fish? Evidence from Swedish lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1353-1362. [PMID: 29890601 DOI: 10.1016/j.scitotenv.2017.12.075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/05/2017] [Accepted: 12/07/2017] [Indexed: 06/08/2023]
Abstract
A number of studies have evaluated the effects of forest harvest on mercury (Hg) concentrations and exports in surface waters, but few studies have tested the effect from forest harvest on the change in fish Hg concentrations over the course of several years after harvest. To address this question, mercury (Hg) concentrations in perch (Perca fluviatilis) muscle tissue from five lakes were analyzed for two years before (2010-2011) and three years after (2013-2015) forest harvest conducted in 2012. Fish Hg concentrations in the clear-cut catchments (n=1373 fish specimens) were related to temporal changes of fish Hg in reference lakes (n=1099 fish specimen) from 19 lakes in the Swedish National Environmental Monitoring Programme. Small (length<100mm) and large perch (length≥100mm) were analyzed separately, due to changing feeding habitats of fish over growing size. There was considerable year-to-year and lake-to-lake variation in fish Hg concentrations (-14%-121%) after forest harvest in the clearcut lakes, according to our first statistical model that count for fish Hg changes. While the effect ascribed to forest harvest varied between years, after three years (in 2015), a significant increase of 26% (p<0.0001) in Hg concentrations of large fish was identified in our second statistical model that pooled all 5 clearcut lakes. The large fish Hg concentrations in the 19 reference lakes also varied, and in 2015 had decreased by 7% (p=0.03) relative to the concentrations in 2010-2011. The majority of the annual changes in fish Hg concentrations in the clearcut lakes after harvest were in the lower range of earlier predictions for high-latitude lakes extrapolated primarily from the effects of forest harvest operations on Hg concentrations in water. Since the risk of forest harvest impacts on Hg extends to fish and not just surface water concentrations, there is even more reason to consider Hg effects in forestry planning, alongside other ecosystem effects.
Collapse
Affiliation(s)
- Pianpian Wu
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden; Department of Earth Sciences, Uppsala University, Uppsala, Sweden
| | - Claudia von Brömssen
- Department of Energy and Technology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Karin Eklöf
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Martyn Futter
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Hans Hultberg
- IVL Swedish Environmental Research Institute, Gothenburg, Sweden
| | - Jaclyn Martin
- Environmental Resources Management, Charlotte, NC, USA
| | - Staffan Åkerblom
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| |
Collapse
|
24
|
Obrist D, Kirk JL, Zhang L, Sunderland EM, Jiskra M, Selin NE. A review of global environmental mercury processes in response to human and natural perturbations: Changes of emissions, climate, and land use. AMBIO 2018; 47:116-140. [PMID: 29388126 PMCID: PMC5794683 DOI: 10.1007/s13280-017-1004-9] [Citation(s) in RCA: 355] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We review recent progress in our understanding of the global cycling of mercury (Hg), including best estimates of Hg concentrations and pool sizes in major environmental compartments and exchange processes within and between these reservoirs. Recent advances include the availability of new global datasets covering areas of the world where environmental Hg data were previously lacking; integration of these data into global and regional models is continually improving estimates of global Hg cycling. New analytical techniques, such as Hg stable isotope characterization, provide novel constraints of sources and transformation processes. The major global Hg reservoirs that are, and continue to be, affected by anthropogenic activities include the atmosphere (4.4-5.3 Gt), terrestrial environments (particularly soils: 250-1000 Gg), and aquatic ecosystems (e.g., oceans: 270-450 Gg). Declines in anthropogenic Hg emissions between 1990 and 2010 have led to declines in atmospheric Hg0 concentrations and HgII wet deposition in Europe and the US (- 1.5 to - 2.2% per year). Smaller atmospheric Hg0 declines (- 0.2% per year) have been reported in high northern latitudes, but not in the southern hemisphere, while increasing atmospheric Hg loads are still reported in East Asia. New observations and updated models now suggest high concentrations of oxidized HgII in the tropical and subtropical free troposphere where deep convection can scavenge these HgII reservoirs. As a result, up to 50% of total global wet HgII deposition has been predicted to occur to tropical oceans. Ocean Hg0 evasion is a large source of present-day atmospheric Hg (approximately 2900 Mg/year; range 1900-4200 Mg/year). Enhanced seawater Hg0 levels suggest enhanced Hg0 ocean evasion in the intertropical convergence zone, which may be linked to high HgII deposition. Estimates of gaseous Hg0 emissions to the atmosphere over land, long considered a critical Hg source, have been revised downward, and most terrestrial environments now are considered net sinks of atmospheric Hg due to substantial Hg uptake by plants. Litterfall deposition by plants is now estimated at 1020-1230 Mg/year globally. Stable isotope analysis and direct flux measurements provide evidence that in many ecosystems Hg0 deposition via plant inputs dominates, accounting for 57-94% of Hg in soils. Of global aquatic Hg releases, around 50% are estimated to occur in China and India, where Hg drains into the West Pacific and North Indian Oceans. A first inventory of global freshwater Hg suggests that inland freshwater Hg releases may be dominated by artisanal and small-scale gold mining (ASGM; approximately 880 Mg/year), industrial and wastewater releases (220 Mg/year), and terrestrial mobilization (170-300 Mg/year). For pelagic ocean regions, the dominant source of Hg is atmospheric deposition; an exception is the Arctic Ocean, where riverine and coastal erosion is likely the dominant source. Ocean water Hg concentrations in the North Atlantic appear to have declined during the last several decades but have increased since the mid-1980s in the Pacific due to enhanced atmospheric deposition from the Asian continent. Finally, we provide examples of ongoing and anticipated changes in Hg cycling due to emission, climate, and land use changes. It is anticipated that future emissions changes will be strongly dependent on ASGM, as well as energy use scenarios and technology requirements implemented under the Minamata Convention. We predict that land use and climate change impacts on Hg cycling will be large and inherently linked to changes in ecosystem function and global atmospheric and ocean circulations. Our ability to predict multiple and simultaneous changes in future Hg global cycling and human exposure is rapidly developing but requires further enhancement.
Collapse
Affiliation(s)
- Daniel Obrist
- Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts, Lowell, One University Ave, Lowell, MA 01854 USA
| | - Jane L. Kirk
- Environment and Climate Change, Canada, 867 Lakeshore Road, Burlington, ON L7P 2X3 Canada
| | - Lei Zhang
- School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023 Jiangsu China
| | - Elsie M. Sunderland
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard T.H. Chan School of Public Health, Harvard University, 29 Oxford Street, Cambridge, MA 02138 USA
| | - Martin Jiskra
- Géosciences Environnement Toulouse, GET-CNRS, CNRS – OMP, 14 Avenue Edouard Belin, 31400 Toulouse, France
| | - Noelle E. Selin
- Institute for Data, Systems, and Society and Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
| |
Collapse
|
25
|
Nasr M, Arp PA. Relating Fish Hg to Variations in Sediment Hg, Climate and Atmospheric Deposition. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/ajcc.2018.73024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
26
|
Poulin BA, Gerbig CA, Kim CS, Stegemeier JP, Ryan JN, Aiken GR. Effects of Sulfide Concentration and Dissolved Organic Matter Characteristics on the Structure of Nanocolloidal Metacinnabar. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13133-13142. [PMID: 29032673 DOI: 10.1021/acs.est.7b02687] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Understanding the speciation of divalent mercury (Hg(II)) in aquatic systems containing dissolved organic matter (DOM) and sulfide is necessary to predict the conversion of Hg(II) to bioavailable methylmercury. We used X-ray absorption spectroscopy to characterize the structural order of mercury in Hg(II)-DOM-sulfide systems for a range of sulfide concentration (1-100 μM), DOM aromaticity (specific ultraviolet absorbance (SUVA254)), and Hg(II)-DOM and Hg(II)-DOM-sulfide equilibration times (4-142 h). In all systems, Hg(II) was present as structurally disordered nanocolloidal metacinnabar (β-HgS). β-HgS nanocolloids were significantly smaller or less ordered at lower sulfide concentration, as indicated by under-coordination of Hg(II) in β-HgS. The size or structural order of β-HgS nanocolloids increased with increasing sulfide abundance and decreased with increasing SUVA254 of the DOM. The Hg(II)-DOM or Hg(II)-DOM-sulfide equilibration times did not significantly influence the extent of structural order in nanocolloidal β-HgS. Geochemical factors that control the structural order of nanocolloidal β-HgS, which are expected to influence nanocolloid surface reactivity and solubility, should be considered in the context of mercury bioavailability.
Collapse
Affiliation(s)
- Brett A Poulin
- U.S. Geological Survey, 3215 Marine St., Suite E127, Boulder, Colorado 80303, United States
| | - Chase A Gerbig
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , UCB 607, Boulder, Colorado 80309, United States
| | - Christopher S Kim
- Schmid College of Science and Technology, Chapman University , One University Drive, Orange, California 92866, United States
| | - John P Stegemeier
- Schmid College of Science and Technology, Chapman University , One University Drive, Orange, California 92866, United States
| | - Joseph N Ryan
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , UCB 607, Boulder, Colorado 80309, United States
| | - George R Aiken
- U.S. Geological Survey, 3215 Marine St., Suite E127, Boulder, Colorado 80303, United States
| |
Collapse
|
27
|
Amyot M, Clayden MG, MacMillan GA, Perron T, Arscott-Gauvin A. Fate and Trophic Transfer of Rare Earth Elements in Temperate Lake Food Webs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6009-6017. [PMID: 28440648 DOI: 10.1021/acs.est.7b00739] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Many mining projects targeting rare earth elements (REE) are in development in North America, but the background concentrations and trophic transfer of these elements in natural environments have not been well characterized. We sampled abiotic and food web components in 14 Canadian temperate lakes unaffected by mines to assess the natural ecosystem fate of REE. Individual REE and total REE concentrations (sum of individual element concentrations, ΣREE) were strongly related with each other throughout different components of lake food webs. Dissolved organic carbon and dissolved oxygen in the water column, as well as ΣREE in sediments, were identified as potential drivers of aqueous ΣREE. Log10 of median bioaccumulation factors ranged from 1.3, 3.7, 4.0, and 4.4 L/kg (wet weight) for fish muscle, zooplankton, predatory invertebrates, and nonpredatory invertebrates, respectively. [ΣREE] in fish, benthic macroinvertebrates, and zooplankton declined as a function of their trophic position, as determined by functional feeding groups and isotopic signatures of nitrogen (δ15N), indicating that REE were subject to trophic dilution. Low concentrations of REE in freshwater fish muscle compared to their potential invertebrate prey suggest that fish fillet consumption is unlikely to be a significant source of REE to humans in areas unperturbed by mining activities. However, other fish predators (e.g., piscivorous birds and mammals) may accumulate REE from whole fish as they are more concentrated than muscle. Overall, this study provides key information on the baseline concentrations and trophic patterns for REE in freshwater temperate lakes in Quebec, Canada.
Collapse
Affiliation(s)
- Marc Amyot
- Groupe de recherche interuniversitaire en limnologie et environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , Pavillon Marie-Victorin CP6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - Meredith G Clayden
- Groupe de recherche interuniversitaire en limnologie et environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , Pavillon Marie-Victorin CP6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - Gwyneth A MacMillan
- Groupe de recherche interuniversitaire en limnologie et environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , Pavillon Marie-Victorin CP6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - Tania Perron
- Groupe de recherche interuniversitaire en limnologie et environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , Pavillon Marie-Victorin CP6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - Alexandre Arscott-Gauvin
- Groupe de recherche interuniversitaire en limnologie et environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , Pavillon Marie-Victorin CP6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7, Canada
| |
Collapse
|
28
|
Yan C, Che F, Zeng L, Wang Z, Du M, Wei Q, Wang Z, Wang D, Zhen Z. Spatial and seasonal changes of arsenic species in Lake Taihu in relation to eutrophication. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 563-564:496-505. [PMID: 27152991 DOI: 10.1016/j.scitotenv.2016.04.132] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/18/2016] [Accepted: 04/18/2016] [Indexed: 06/05/2023]
Abstract
Spatial and seasonal variations of arsenic species in Lake Taihu (including Zhushan Bay, Meiliang Bay, Gonghu Bay, and Southern Taihu) were investigated. Relatively high levels of total arsenic (TAs) and arsenate (As(V)) were observed in hyper-eutrophic regions during summer and autumn, which is attributed to exogenous contamination and seasonal endogenous release from sediments. The distributions of TAs and As(V) were significantly affected by total phosphorus, iron, manganese, and dissolved organic carbon. Arsenite (As(III)) and methylarsenicals (the sum of monomethylarsenic acid (MMA(V)) and dimethylarsenic acid (DMA(V))), mainly from biotransformation of As(V), were affected by temperature-controlled microalgae activities and local water quality parameters, exhibiting significantly higher concentrations and proportions in hyper-eutrophic and middle eutrophic regions during summer compared to mesotrophic region. The eutrophic environment, which induces changes in the main water quality parameters such as phosphorus, chlorophyll-a, iron, manganese, and dissolved organic carbon, can favor the biogeochemical cycling of arsenic in the aquatic systems.
Collapse
Affiliation(s)
- Changzhou Yan
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Feifei Che
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liqing Zeng
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zaosheng Wang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Miaomiao Du
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Qunshan Wei
- College of Environmental Science & Engineering, Donghua University, Songjiang District, Shanghai 201620, China
| | - Zhenhong Wang
- College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China
| | - Dapeng Wang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuo Zhen
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| |
Collapse
|
29
|
Yang Z, Fang W, Lu X, Sheng GP, Graham DE, Liang L, Wullschleger SD, Gu B. Warming increases methylmercury production in an Arctic soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 214:504-509. [PMID: 27131808 DOI: 10.1016/j.envpol.2016.04.069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 06/05/2023]
Abstract
Rapid temperature rise in Arctic permafrost impacts not only the degradation of stored soil organic carbon (SOC) and climate feedback, but also the production and bioaccumulation of methylmercury (MeHg) toxin that can endanger humans, as well as wildlife in terrestrial and aquatic ecosystems. Currently little is known concerning the effects of rapid permafrost thaw on microbial methylation and how SOC degradation is coupled to MeHg biosynthesis. Here we describe the effects of warming on MeHg production in an Arctic soil during an 8-month anoxic incubation experiment. Net MeHg production increased >10 fold in both organic- and mineral-rich soil layers at warmer (8 °C) than colder (-2 °C) temperatures. The type and availability of labile SOC, such as reducing sugars and ethanol, were particularly important in fueling the rapid initial biosynthesis of MeHg. Freshly amended mercury was more readily methylated than preexisting mercury in the soil. Additionally, positive correlations between mercury methylation and methane and ferrous ion production indicate linkages between SOC degradation and MeHg production. These results show that climate warming and permafrost thaw could potentially enhance MeHg production by an order of magnitude, impacting Arctic terrestrial and aquatic ecosystems by increased exposure to mercury through bioaccumulation and biomagnification in the food web.
Collapse
Affiliation(s)
- Ziming Yang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Wei Fang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, China
| | - Xia Lu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Guo-Ping Sheng
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, China
| | - David E Graham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Liyuan Liang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Stan D Wullschleger
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| |
Collapse
|
30
|
Girard C, Leclerc M, Amyot M. Photodemethylation of Methylmercury in Eastern Canadian Arctic Thaw Pond and Lake Ecosystems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:3511-3520. [PMID: 26938195 DOI: 10.1021/acs.est.5b04921] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Permafrost thaw ponds of the warming Eastern Canadian Arctic are major landscape constituents and often display high levels of methylmercury (MeHg). We examined photodegradation potentials in high-dissolved organic matter (DOC) thaw ponds on Bylot Island (BYL) and a low-DOC oligotrophic lake on Cornwallis Island (Char Lake). In BYL, the ambient MeHg photodemethylation (PD) rate over 48 h of solar exposure was 6.1 × 10(-3) m(2) E(-1), and the rate in MeHg amended samples was 9.3 × 10(-3) m(2) E(-1). In contrast, in low-DOC Char Lake, PD was only observed in the first 12 h, which suggests that PD may not be an important loss process in polar desert lakes. Thioglycolic acid addition slowed PD, while glutathione and chlorides did not impact northern PD rates. During an ecosystem-wide experiment conducted in a covered BYL pond, there was neither net MeHg increase in the dark nor loss attributable to PD following re-exposure to sunlight. We propose that high-DOC Arctic thaw ponds are more prone to MeHg PD than nearby oligotrophic lakes, likely through photoproduction of reactive species rather than via thiol complexation. However, at the ecosystem level, these ponds, which are widespread through the Arctic, remain likely sources of MeHg for neighboring systems.
Collapse
Affiliation(s)
- Catherine Girard
- Centre d'études nordiques (CEN), Département de sciences biologiques, Université de Montréal , 90 Vincent-d'Indy, Montréal, Quebec Canada
| | - Maxime Leclerc
- Groupe de recherche interuniversitaire en limnologie et en environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , 90 Vincent-d'Indy, Montréal, Quebec Canada
| | - Marc Amyot
- Centre d'études nordiques (CEN), Département de sciences biologiques, Université de Montréal , 90 Vincent-d'Indy, Montréal, Quebec Canada
- Groupe de recherche interuniversitaire en limnologie et en environnement aquatique (GRIL), Département de sciences biologiques, Université de Montréal , 90 Vincent-d'Indy, Montréal, Quebec Canada
| |
Collapse
|