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Jędruch A, Bełdowski J, Bełdowska M. Mercury dynamics at the base of the pelagic food web of the Gulf of Gdańsk, southern Baltic Sea. MARINE POLLUTION BULLETIN 2024; 202:116363. [PMID: 38621354 DOI: 10.1016/j.marpolbul.2024.116363] [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: 01/29/2024] [Revised: 02/25/2024] [Accepted: 04/07/2024] [Indexed: 04/17/2024]
Abstract
Planktonic organisms, which have direct contact with water, serve as the entry point for mercury (Hg), into the marine food web, impacting its levels in higher organisms, including fish, mammals, and humans who consume seafood. This study provides insights into the distribution and behavior of Hg within the Baltic Sea, specifically the Gulf of Gdańsk, focusing on pelagic primary producers and consumers. Phytoplankton Hg levels were primarily influenced by its concentrations in water, while Hg concentrations in zooplankton resulted from dietary exposure through suspended particulate matter and phytoplankton consumption. Hg uptake by planktonic organisms, particularly phytoplankton, was highly efficient, with Hg concentrations four orders of magnitude higher than those in the surrounding water. However, unlike biomagnification of Hg between SPM and zooplankton, biomagnification between zooplankton and phytoplankton was not apparent, likely due to the low trophic position and small size of primary consumers, high Hg elimination rates, and limited absorption.
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Affiliation(s)
- Agnieszka Jędruch
- Polish Academy of Sciences, Institute of Oceanology, Department of Marine Chemistry and Biochemistry, Powstańców Warszawy 55, 81-712 Sopot, Poland; University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378 Gdynia, Poland.
| | - Jacek Bełdowski
- Polish Academy of Sciences, Institute of Oceanology, Department of Marine Chemistry and Biochemistry, Powstańców Warszawy 55, 81-712 Sopot, Poland
| | - Magdalena Bełdowska
- University of Gdańsk, Faculty of Oceanography and Geography, Department of Chemical Oceanography and Marine Geology, Marszałka Józefa Piłsudskiego 46, 81-378 Gdynia, Poland
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2
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Tesán-Onrubia JA, Heimbürger-Boavida LE, Dufour A, Harmelin-Vivien M, García-Arévalo I, Knoery J, Thomas B, Carlotti F, Tedetti M, Bănaru D. Bioconcentration, bioaccumulation and biomagnification of mercury in plankton of the Mediterranean Sea. MARINE POLLUTION BULLETIN 2023; 194:115439. [PMID: 37639915 DOI: 10.1016/j.marpolbul.2023.115439] [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: 03/30/2023] [Revised: 06/30/2023] [Accepted: 08/18/2023] [Indexed: 08/31/2023]
Abstract
Plankton plays a prominent role in the bioaccumulation of mercury (Hg). The MERITE-HIPPOCAMPE campaign was carried out in spring 2019 along a north-south transect including coastal and offshore areas of the Mediterranean Sea. Sampling of sea water and plankton by pumping and nets was carried out in the chlorophyll maximum layer. Two size-fractions of phytoplankton (0.7-2.7 and 2.7-20 μm) and five of zooplankton (between 60 and >2000 μm) were separated, and their total mercury (THg) and monomethylmercury (MMHg) contents were measured. Bioconcentration of THg was significantly higher in the smallest phytoplankton size-fraction dominated by Synechococcus spp. The bioaccumulation and biomagnification of MMHg in zooplankton was influenced by size, food sources, biochemical composition and trophic level. MMHg was biomagnified in the plankton food web, while THg decreased toward higher trophic levels. Higher MMHg concentrations were measured in oligotrophic areas. Plankton communities in the Southern Mediterranean Sea had lower MMHg concentrations than those in the Northern Mediterranean Sea. These results highlighted the influence of environmental conditions and trophodynamics on the transfer of Hg in Mediterranean plankton food webs, with implications for higher trophic level consumers.
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Affiliation(s)
| | | | - Aurélie Dufour
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, Marseille, France
| | | | | | - Joël Knoery
- Ifremer, CCEM Contamination Chimique des Ecosystèmes Marins, F-44311 Nantes, France
| | - Bastien Thomas
- Ifremer, CCEM Contamination Chimique des Ecosystèmes Marins, F-44311 Nantes, France
| | - François Carlotti
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, Marseille, France
| | - Marc Tedetti
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, Marseille, France
| | - Daniela Bănaru
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, Marseille, France.
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Asiedu DA, Søndergaard J, Jónasdóttir S, Juul-Pedersen T, Koski M. Concentration of mercury and other metals in an Arctic planktonic food web under a climate warming scenario. MARINE POLLUTION BULLETIN 2023; 194:115436. [PMID: 37660452 DOI: 10.1016/j.marpolbul.2023.115436] [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: 06/15/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 09/05/2023]
Abstract
Arctic marine ecosystems act as a global sink of mercury (Hg) and other metals, and high concentrations of these have been measured in higher trophic-level organisms. Nevertheless, the concentrations of metals at the basis of the marine food web in the Arctic is less known despite the likelihood of biomagnification from dietary sources. We investigated the concentrations of mercury (Hg) and other metals in different size fractions of plankton in West Greenland. All size fractions contained detectable levels of Hg (ranging from 4.8 to 241.3 ng g dw-1) at all stations, although with high geographic variability, likely reflecting the sources of mercury (e.g., meltwater). In many cases, the concentrations in the larger-size fractions were lower than in the smaller-size fractions, suggesting depuration through the metabolic activity of mesozooplankton. Concentrations of Cd, Pb, V, Ni, and Cr were higher than previously reported elsewhere in the Arctic.
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Affiliation(s)
- Delove Abraham Asiedu
- National Institute of Aquatic Resources, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Jens Søndergaard
- Department of Ecoscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Sigrun Jónasdóttir
- National Institute of Aquatic Resources, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Thomas Juul-Pedersen
- Greenland Climate Research Center, Greenland Institute of Natural Resources, Nuuk 3900, Greenland
| | - Marja Koski
- National Institute of Aquatic Resources, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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4
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Wang K, Liu G, Cai Y. Effects of natural particles on photo-reduction of divalent mercury in everglades waters. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121327. [PMID: 36822309 DOI: 10.1016/j.envpol.2023.121327] [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: 08/15/2022] [Revised: 02/17/2023] [Accepted: 02/19/2023] [Indexed: 06/18/2023]
Abstract
Photo-reduction of divalent mercury (Hg(II)) in waters plays an important role in the air-water exchange of Hg and biogeochemical cycle of Hg in general. As previous studies on photo-reduction of Hg(II) have mainly focused on dissolved Hg species, the effects of natural particles on photo-reduction of Hg(II) remain largely unknown, except the presumed light attenuating effect through light absorption and scattering. Considering the prevalence of particulate Hg due to adsorption of divalent and elemental Hg species on aquatic particles that are often photochemically active, natural particles may play a more direct role in Hg photo-reduction. By using incubation experiments with Everglades waters and additions of isotopically labelled Hg(II), we studied the effects of particles on photo-reduction of Hg(II) in natural waters. The effect of natural particles on Hg(II) photo-reduction was not observed between filtered or unfiltered Everglades waters, probably because of the low particle concentrations (<3 mg/L). When suspended particles isolated from original water was used to amend its concentration to 6.9 times the ambient Everglades waters, photo-reduction of Hg(II) was significantly enhanced. Given that the particles in Everglades waters are often semiconducting in nature, particulate Hg(II) may undergo heterogenous photo-reduction and lead to higher Hg(II) photo-reduction. However, in Everglades waters with both suspended and settling particles, high concentrations (∼100 mg/L) of particles did not result in enhanced Hg(II) photo-reduction. In this case, the enhancing effects of particles on Hg(II) photo-reduction were likely offset by inhibiting effects due to the higher irradiation attenuation and lower Hg(II) partition coefficients of the settling particles with larger sizes. This study highlights the direct involvements of particles in photoreaction of Hg species in natural waters and calls for more mechanistic research on heterogenous photo-reduction of Hg species on particles' surfaces.
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Affiliation(s)
- Kang Wang
- Department of Chemistry & Biochemistry and Southeast Environmental Research Center, Florida International University, Miami, FL, 33199, USA
| | - Guangliang Liu
- Department of Chemistry & Biochemistry and Southeast Environmental Research Center, Florida International University, Miami, FL, 33199, USA
| | - Yong Cai
- Department of Chemistry & Biochemistry and Southeast Environmental Research Center, Florida International University, Miami, FL, 33199, USA.
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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.
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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
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Mao L, Liu X, Wang Z, Wang B, Lin C, Xin M, Zhang BT, Wu T, He M, Ouyang W. Trophic transfer and dietary exposure risk of mercury in aquatic organisms from urbanized coastal ecosystems. CHEMOSPHERE 2021; 281:130836. [PMID: 33991905 DOI: 10.1016/j.chemosphere.2021.130836] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 06/12/2023]
Abstract
In this study, 26 surface seawater samples, 26 surface sediment samples and 114 organisms were collected to study the trophic transfer and dietary exposure risk of mercury (Hg) in organisms from the Jiaozhou Bay, which is a typical semi-enclosed urbanized bay. The total mercury (THg) and methylmercury (MeHg) concentrations did not exceed the threshold limits and performed as: fish > crustaceans > mollusks. The trophic level values (TLs) were less than 3 in all the groups, indicating simple structure of food chain. With the increasing δ15N value, THg and MeHg were significantly biomagnified in the mollusks and fish but not in the crustaceans. In addition, the bioaccumulation and biomagnification of MeHg were higher than inorganic mercury (IHg) in the aquatic food chain. Target hazard quotient (THQ) and provisional tolerable weekly intake (PTWI) indicated that Hg exposure via consumption of seafood from the Jiaozhou Bay did not pose significant health risks for general population. Consuming fish will face the higher health risk than crustaceans and mollusks, especially in urban regions. Moreover, the risk of MeHg caused by intaking seafood deserved more attention. Trophic transfer function (TTF) explicated the transfer of Hg in the ecosystem and higher trophic transfer efficiency of MeHg than IHg. TTF interpreted the terrestrial input of Hg should be controlled to ensure the safety of consuming seafood from the Jiaozhou Bay.
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Affiliation(s)
- Lulu Mao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Xitao Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
| | - Zongxing Wang
- The First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Baodong Wang
- The First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Chunye Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Ming Xin
- The First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Bo-Tao Zhang
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Tingting Wu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Mengchang He
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Wei Ouyang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China; Advanced Interdisciplinary Institute of Environment and Ecology, Beijing Normal University, Zhuhai, 519087, China
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7
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Loria A, Archambault P, Burt A, Ehrman A, Grant C, Power M, Stern GA. Mercury and stable isotope (δ13C and δ15N) trends in decapods of the Beaufort Sea. Polar Biol 2020. [DOI: 10.1007/s00300-020-02646-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Mao L, Liu X, Wang B, Lin C, Xin M, Zhang BT, Wu T, He M, Ouyang W. Occurrence and risk assessment of total mercury and methylmercury in surface seawater and sediments from the Jiaozhou Bay, Yellow Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 714:136539. [PMID: 31981874 DOI: 10.1016/j.scitotenv.2020.136539] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 01/03/2020] [Accepted: 01/03/2020] [Indexed: 06/10/2023]
Abstract
The Jiaozhou Bay is a semi-enclosed bay located in the middle of the Yellow Sea. Effluents from wastewater treatment plants have been carried into the bay, which has significantly increased the deposition of mercury. The spatial distributions of total mercury (THg) and methylmercury (MeHg) in dissolved state, in suspended matters of seawater and surface sediments at 26 locations inside the Jiaozhou Bay and five surrounding rivers in April 2018 were examined. The contents of THg and MeHg found along the eastern coast were higher than those found along the western coast, which indicated the impact of human activities (river input) on the Jiaozhou Bay. The partition coefficient (LogKd) was used to express the distribution relationships of THg and MeHg in suspended matters and dissolved state, and it was concluded that suspended matter was the main reservoir of mercury in Jiaozhou Bay seawater. The correlations between contents and physicochemical properties of seawater showed that THg and MeHg concentrations in seawater decreased with increasing salinity and pH. The effects of the mean grain diameter (MGD) and sediment organic matter (SOM) on the THg and MeHg in surface sediments were also discussed. Principal component analysis (PCA) was used to obtain the factors determining the methylation proportion in the surface sediments, indicating that the combination of human activities and natural processes affected the degree of methylation in the sediments. The spatial distribution of THg, MeHg and MeHg% was suggested to be disturbed by the interaction of natural processes and human activities (river input) by the correlation analysis of the corresponding pollutant concentrations among seawater and. Although the concentrations of THg and MeHg in seawater and sediments of the Jiaozhou Bay did not exceed the Chinese regulatory standards, the pollution levels of THg and MeHg were comparable to those in other bays in the world.
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Affiliation(s)
- Lulu Mao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xitao Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Baodong Wang
- The First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Chunye Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Ming Xin
- The First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Bo-Tao Zhang
- College of Water Sciences, Beijing University, Beijing 100875, China
| | - Tingting Wu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Mengchang He
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Wei Ouyang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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Mercury-methylating bacteria are associated with copepods: A proof-of-principle survey in the Baltic Sea. PLoS One 2020; 15:e0230310. [PMID: 32176728 PMCID: PMC7075563 DOI: 10.1371/journal.pone.0230310] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 02/26/2020] [Indexed: 01/08/2023] Open
Abstract
Methylmercury (MeHg) is a potent neurotoxin that biomagnifies in marine food webs. Inorganic mercury (Hg) methylation is conducted by heterotrophic bacteria inhabiting sediment or settling detritus, but endogenous methylation by the gut microbiome of animals in the lower food webs is another possible source. We examined the occurrence of the bacterial gene (hgcA), required for Hg methylation, in the guts of dominant zooplankters in the Northern Baltic Sea. A qPCR assay targeting the hgcA sequence in three main clades (Deltaproteobacteria, Firmicutes and Archaea) was used in the field-collected specimens of copepods (Acartia bifilosa, Eurytemora affinis, Pseudocalanus acuspes and Limnocalanus macrurus) and cladocerans (Bosmina coregoni maritima and Cercopagis pengoi). All copepods were found to carry hgcA genes in their gut microbiome, whereas no amplification was recorded in the cladocerans. In the copepods, hgcA genes belonging to only Deltaproteobacteria and Firmicutes were detected. These findings suggest a possibility that endogenous Hg methylation occurs in zooplankton and may contribute to seasonal, spatial and vertical MeHg variability in the water column and food webs. Additional molecular and metagenomics studies are needed to identify bacteria carrying hgcA genes and improve their quantification in microbiota.
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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.
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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
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11
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Wang H, Xia X, Liu R, Wang Z, Zhai Y, Lin H, Wen W, Li Y, Wang D, Yang Z, Muir DCG, Crittenden JC. Dietary Uptake Patterns Affect Bioaccumulation and Biomagnification of Hydrophobic Organic Compounds in Fish. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4274-4284. [PMID: 30884228 DOI: 10.1021/acs.est.9b00106] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Biomagnification of hydrophobic organic compounds (HOCs) increases the eco-environmental risks they pose. Here, we gained mechanistic insights into biomagnification of deuterated polycyclic aromatic hydrocarbons (PAHs- d10) in zebrafish with carefully controlled water (ng L-1) by a passive dosing method and dietary exposures using pre-exposed Daphnia magna and fish food. A new bioaccumulation kinetic model for fish was established to take into account discrete dietary uptake, while the frequently used model regards dietary uptake as a continuous process. We found that when freely dissolved concentrations of the PAHs- d10 were constant in water, the intake amount of the PAHs- d10 played an important role in affecting their steady-state concentrations in zebrafish, and there was a peak concentration in zebrafish after each dietary uptake. Moreover, considering the randomness of predation, the Monte Carlo simulation results showed that the probabilities of biomagnification of the PAHs- d10 in zebrafish increased with their dietary uptake amount and frequency. This study indicates that in addition to the well-known lipid-water partitioning, the bioaccumulation of HOCs in fish is also a discontinuous kinetic process caused by the fluctuation of HOC concentration in the gastrointestinal tract as a result of the discrete food ingestion. The discontinuity and randomness of dietary uptake can partly explain the differences among aquatic ecosystems with respect to biomagnification for species at similar trophic levels and provides new insight for future analysis of experimental and field bioaccumulation data for fish.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Derek C G Muir
- Aquatic Contaminants Research Division , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 Canada
- School of Environment , Jinan University , Guangzhou , 510632 , China
| | - John C Crittenden
- Brook Byers Institute for Sustainable Systems and School of Civil and Environmental Engineering , Georgia Institute of Technology , 828 West Peachtree Street , Atlanta , Georgia 30332 , United States
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12
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Buckman KL, Lane O, Kotnik J, Bratkic A, Sprovieri F, Horvat M, Pirrone N, Evers DC, Chen CY. Spatial and taxonomic variation of mercury concentration in low trophic level fauna from the Mediterranean Sea. ECOTOXICOLOGY (LONDON, ENGLAND) 2018; 27:1341-1352. [PMID: 30315417 PMCID: PMC6345403 DOI: 10.1007/s10646-018-1986-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/15/2018] [Indexed: 06/08/2023]
Abstract
Studies of mercury (Hg) in the Mediterranean Sea have focused on pollution sources, air-sea mercury exchange, abiotic mercury cycling, and seafood. Much less is known about methylmercury (MeHg) concentrations in the lower food web. Zooplankton and small fish were sampled from the neuston layer at both coastal and open sea stations in the Mediterranean Sea during three cruise campaigns undertaken in the fall of 2011 and the summers of 2012 and 2013. Zooplankton and small fish were sorted by morphospecies, and the most abundant taxa (e.g. euphausiids, isopods, hyperiid amphipods) analyzed for methylmercury (MeHg) concentration. Unfiltered water samples were taken during the 2011 and 2012 cruises and analyzed for MeHg concentration. Multiple taxa suggested elevated MeHg concentrations in the Tyrrhenian and Balearic Seas in comparison with more eastern and western stations in the Mediterranean Sea. Spatial variation in zooplankton MeHg concentration is positively correlated with single time point whole water MeHg concentration for euphausiids and mysids and negatively correlated with maximum chlorophyll a concentration for euphausiids, mysids, and "smelt" fish. Taxonomic variation in MeHg concentration appears driven by taxonomic grouping and feeding mode. Euphausiids, due to their abundance, relative larger size, importance as a food source for other fauna, and observed relationship with surface water MeHg are a good candidate biotic group to evaluate for use in monitoring the bioavailability of MeHg for trophic transfer in the Mediterranean and potentially globally.
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Affiliation(s)
- Kate L Buckman
- Dartmouth College, Department of Biological Sciences, Hanover, NH, USA.
| | - Oksana Lane
- Biodiversity Research Institute, Portland, Maine, USA
| | - Jože Kotnik
- Jožef Stefan Institute, Department of Environmental Sciences, Ljubljana, Slovenia
| | - Arne Bratkic
- Jožef Stefan Institute, Department of Environmental Sciences, Ljubljana, Slovenia
- International Postgraduate School Jožef Stefan, Ljubljana, Slovenia
- Vrije Universiteit Brussel, Analytical, Environmental, and Geo-Chemistry, Brussels, Belgium
| | | | - Milena Horvat
- Jožef Stefan Institute, Department of Environmental Sciences, Ljubljana, Slovenia
- International Postgraduate School Jožef Stefan, Ljubljana, Slovenia
| | | | - David C Evers
- Biodiversity Research Institute, Portland, Maine, USA
| | - Celia Y Chen
- Dartmouth College, Department of Biological Sciences, Hanover, NH, USA
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13
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Cherel Y, Barbraud C, Lahournat M, Jaeger A, Jaquemet S, Wanless RM, Phillips RA, Thompson DR, Bustamante P. Accumulate or eliminate? Seasonal mercury dynamics in albatrosses, the most contaminated family of birds. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 241:124-135. [PMID: 29803026 DOI: 10.1016/j.envpol.2018.05.048] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/11/2018] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
Albatrosses (Diomedeidae) are iconic pelagic seabirds whose life-history traits (longevity, high trophic position) put them at risk of high levels of exposure to methylmercury (MeHg), a powerful neurotoxin that threatens humans and wildlife. Here, we report total Hg (THg) concentrations in body feathers from 516 individual albatrosses from 35 populations, including all 20 taxa breeding in the Southern Ocean. Our key finding is that albatrosses constitute the family of birds with the highest levels of contamination by Hg, with mean feather THg concentrations in different populations ranging from moderate (3.8 μg/g) to exceptionally high (34.6 μg/g). Phylogeny had a significant effect on feather THg concentrations, with the mean decreasing in the order Diomedea > Phoebetria > Thalassarche. Unexpectedly, moulting habitats (reflected in feather δ13C values) was the main driver of feather THg concentrations, indicating increasing MeHg exposure with decreasing latitude, from Antarctic to subtropical waters. The role of moulting habitat suggests that the majority of MeHg eliminated into feathers by albatrosses is from recent food intake (income strategy). They thus differ from species that depurate MeHg into feathers that has been accumulated in internal tissues between two successive moults (capital strategy). Since albatrosses are amongst the most threatened families of birds, it is noteworthy that two albatrosses listed as Critical by the World Conservation Union (IUCN) that moult and breed in temperate waters are the most Hg-contaminated species (the Amsterdam and Tristan albatrosses). These data emphasize the urgent need for robust assessment of the impact of Hg contamination on the biology of albatrosses and they document the high MeHg level exposure of wildlife living in the most remote marine areas on Earth.
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Affiliation(s)
- Yves Cherel
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-Université de La Rochelle, 79360 Villiers-en-Bois, France.
| | - Christophe Barbraud
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-Université de La Rochelle, 79360 Villiers-en-Bois, France
| | - Maxime Lahournat
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-Université de La Rochelle, 79360 Villiers-en-Bois, France; Littoral, Environnement et Sociétés, UMR 7266 du CNRS-Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Audrey Jaeger
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-Université de La Rochelle, 79360 Villiers-en-Bois, France; Laboratoire ENTROPIE, UMR 9220 du CNRS- IRD-Université de La Réunion, 15 Avenue René Cassin, BP 92003, 97744 Saint-Denis, La Réunion, France
| | - Sébastien Jaquemet
- Laboratoire ENTROPIE, UMR 9220 du CNRS- IRD-Université de La Réunion, 15 Avenue René Cassin, BP 92003, 97744 Saint-Denis, La Réunion, France
| | - Ross M Wanless
- DST/NRF Centre of Excellence, Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, South Africa
| | - Richard A Phillips
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - David R Thompson
- National Institute of Water and Atmospheric Research Ltd, 301 Evans Bay Parade, Hataitai, Wellington 6021, New Zealand
| | - Paco Bustamante
- Littoral, Environnement et Sociétés, UMR 7266 du CNRS-Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
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14
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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.
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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
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15
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Wang K, Munson KM, Beaupré-Laperrière A, Mucci A, Macdonald RW, Wang F. Subsurface seawater methylmercury maximum explains biotic mercury concentrations in the Canadian Arctic. Sci Rep 2018; 8:14465. [PMID: 30262886 PMCID: PMC6160454 DOI: 10.1038/s41598-018-32760-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/12/2018] [Indexed: 01/04/2023] Open
Abstract
Mercury (Hg) is a contaminant of major concern in Arctic marine ecosystems. Decades of Hg observations in marine biota from across the Canadian Arctic show generally higher concentrations in the west than in the east. Various hypotheses have attributed this longitudinal biotic Hg gradient to regional differences in atmospheric or terrestrial inputs of inorganic Hg, but it is methylmercury (MeHg) that accumulates and biomagnifies in marine biota. Here, we present high-resolution vertical profiles of total Hg and MeHg in seawater along a transect from the Canada Basin, across the Canadian Arctic Archipelago (CAA) and Baffin Bay, and into the Labrador Sea. Total Hg concentrations are lower in the western Arctic, opposing the biotic Hg distributions. In contrast, MeHg exhibits a distinctive subsurface maximum at shallow depths of 100–300 m, with its peak concentration decreasing eastwards. As this subsurface MeHg maximum lies within the habitat of zooplankton and other lower trophic-level biota, biological uptake of subsurface MeHg and subsequent biomagnification readily explains the biotic Hg concentration gradient. Understanding the risk of MeHg to the Arctic marine ecosystem and Indigenous Peoples will thus require an elucidation of the processes that generate and maintain this subsurface MeHg maximum.
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Affiliation(s)
- Kang Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Kathleen M Munson
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Alexis Beaupré-Laperrière
- GEOTOP, and Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec, H3A 0E8, Canada
| | - Alfonso Mucci
- GEOTOP, and Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec, H3A 0E8, Canada
| | - Robie W Macdonald
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.,Institute of Ocean Sciences, Department of Fisheries and Oceans, Sidney, British Columbia, V8L 4B2, Canada
| | - Feiyue Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
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16
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Harding G, Dalziel J, Vass P. Bioaccumulation of methylmercury within the marine food web of the outer Bay of Fundy, Gulf of Maine. PLoS One 2018; 13:e0197220. [PMID: 30011281 PMCID: PMC6047777 DOI: 10.1371/journal.pone.0197220] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/27/2018] [Indexed: 12/02/2022] Open
Abstract
Mercury and methylmercury were measured in seawater and biota collected from the outer Bay of Fundy to better document mercury bioaccumulation in a temperate marine food web. The size of an organism, together with δ13 C and δ15 N isotopes, were measured to interpret mercury levels in biota ranging in size from microplankton (25μm) to swordfish, dolphins and whales. Levels of mercury in seawater were no different with depth and not elevated relative to upstream sources. The δ13 C values of primary producers were found to be inadequate to specify the original energy source of various faunas, however, there was no reason to separate the food web into benthic, demersal and pelagic food chains because phytoplankton has been documented to almost exclusively fuel the ecosystem. The apparent abrupt increase in mercury content from "seawater" to phytoplankton, on a wet weight basis, can be explained from an environmental volume basis by the exponential increase in surface area of smaller particles included in "seawater" determinations. This physical sorption process may be important up to the macroplankton size category dominated by copepods according to the calculated biomagnification factors (BMF). The rapid increase in methylmercury concentration, relative to the total mercury, between the predominantly phytoplankton (<125μm) and the zooplankton categories is likely augmented by gut microbe methylation. Further up the food chain, trophic transfer of methylmercury dominates resulting in biomagnification factors greater than 10 in swordfish, Atlantic bluefin tuna, harbour porpoise, Atlantic white-sided dolphin and common thresher shark. The biomagnification power of the northern Gulf of Maine ecosystem is remarkably similar to that measured in tropical, subtropical, other temperate and arctic oceanic ecozones.
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Affiliation(s)
- Gareth Harding
- Bedford Institute of Oceanography, Department of Fisheries and Oceans, Dartmouth, Nova Scotia, Canada
| | - John Dalziel
- Environment Canada, Dartmouth, Nova Scotia, Canada
| | - Peter Vass
- Bedford Institute of Oceanography, Department of Fisheries and Oceans, Dartmouth, Nova Scotia, Canada
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17
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Cesário R, Mota AM, Caetano M, Nogueira M, Canário J. Mercury and methylmercury transport and fate in the water column of Tagus estuary (Portugal). MARINE POLLUTION BULLETIN 2018; 127:235-250. [PMID: 29475660 DOI: 10.1016/j.marpolbul.2017.11.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/25/2017] [Accepted: 11/30/2017] [Indexed: 06/08/2023]
Abstract
Six campaigns were performed in North Channel (CNOR), Barcas Channel (BC) and lower zones (EZ) of Tagus estuary to better understand methylmercury (MMHg) and mercury (Hg) transport and fate. Highest concentrations of particulate and dissolved MMHg were observed in CNOR in bottom waters and in the warmest months. The MMHg distribution coefficients between particulate and dissolved fractions were mainly influenced by particulate matter and dissolved organic carbon. The values were slightly higher in summer than in winter and in CNOR. Overall, results established that the tidal effect is a main driver on the transport and fate of Hg and MMHg from CNOR to outer areas, evidenced by the exportation of the Hg species from CNOR to the upstream station in high tide and to the downstream one in low tide. Therefore, CNOR may be considered a source of Hg and MMHg to the outer estuary.
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Affiliation(s)
- Rute Cesário
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal; IPMA-Instituto Português do Mar e Atmosfera, Rua Alfredo Magalhães Ramalho, 6, 1495-006 Lisboa, Portugal
| | - Ana Maria Mota
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal
| | - Miguel Caetano
- IPMA-Instituto Português do Mar e Atmosfera, Rua Alfredo Magalhães Ramalho, 6, 1495-006 Lisboa, Portugal
| | - Marta Nogueira
- IPMA-Instituto Português do Mar e Atmosfera, Rua Alfredo Magalhães Ramalho, 6, 1495-006 Lisboa, Portugal
| | - João Canário
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal.
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18
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Pelletier AR, Castello L, Zhulidov AV, Gurtovaya TY, Robarts RD, Holmes RM, Zhulidov DA, Spencer RGM. Temporal and Longitudinal Mercury Trends in Burbot (Lota lota) in the Russian Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13436-13442. [PMID: 29083154 DOI: 10.1021/acs.est.7b03929] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Current understanding of mercury (Hg) dynamics in the Arctic is hampered by a lack of data in the Russian Arctic region, which comprises about half of the entire Arctic watershed. This study quantified temporal and longitudinal trends in total mercury (THg) concentrations in burbot (Lota lota) in eight rivers of the Russian Arctic between 1980 and 2001, encompassing an expanse of 118 degrees of longitude. Burbot THg concentrations declined by an average of 2.6% annually across all eight rivers during the study period, decreasing by 39% from 0.171 μg g-1 wet weight (w.w.) in 1980 to 0.104 μg g-1 w.w. in 2001. THg concentrations in burbot also declined by an average of 1.8% per 10° of longitude from west to east across the study area between 1988 and 2001. These results, in combination with those of previous studies, suggest that Hg trends in Arctic freshwater fishes before 2001 were spatially and temporally heterogeneous, as those in the North American Arctic were mostly increasing while those in the Russian Arctic were mostly decreasing. It is suggested that Hg trends in Arctic animals may be influenced by both depositional and postdepositional processes.
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Affiliation(s)
- Alexander R Pelletier
- Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, United States
| | - Leandro Castello
- Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, United States
| | - Alexander V Zhulidov
- South Russian Centre for Preparation and Implementation of International Projects , Rostov-on-Don, Russia
| | - Tatiana Yu Gurtovaya
- South Russian Centre for Preparation and Implementation of International Projects , Rostov-on-Don, Russia
| | | | - Robert M Holmes
- Woods Hole Research Center , Falmouth, Massachusetts 02540, United States
| | - Daniel A Zhulidov
- South Russian Centre for Preparation and Implementation of International Projects , Rostov-on-Don, Russia
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19
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Pomerleau C, Stern GA, Pućko M, Foster KL, Macdonald RW, Fortier L. Pan-Arctic concentrations of mercury and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in marine zooplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 551-552:92-100. [PMID: 26874765 DOI: 10.1016/j.scitotenv.2016.01.172] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 06/05/2023]
Abstract
Zooplankton play a central role in marine food webs, dictating the quantity and quality of energy available to upper trophic levels. They act as "keystone" species in transfer of mercury (Hg) up through the marine food chain. Here, we present the first Pan-Arctic overview of total and monomethylmercury concentrations (THg and MMHg) and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in selected zooplankton species by assembling data collected between 1998 and 2012 from six arctic regions (Laptev Sea, Chukchi Sea, southeastern Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay and northern Baffin Bay). MMHg concentrations in Calanus spp., Themisto spp. and Paraeuchaeta spp. were found to increase with higher δ(15)N and lower δ(13)C. The southern Beaufort Sea exhibited both the highest THg and MMHg concentrations. Biomagnification of MMHg between Calanus spp. and two of its known predators, Themisto spp. and Paraeuchaeta spp., was greatest in the southern Beaufort Sea. Our results show large geographical variations in Hg concentrations and isotopic signatures for individual species related to regional ecosystem features, such as varying water masses and freshwater inputs, and highlight the increased exposure to Hg in the marine food chain of the southern Beaufort Sea.
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Affiliation(s)
- Corinne Pomerleau
- Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; Greenland Institute of Natural Resources, Kivioq 2, Nuuk 3900, Greenland.
| | - Gary A Stern
- Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Monika Pućko
- Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | | | - Robie W Macdonald
- Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, BC V8L 4B2, Canada
| | - Louis Fortier
- Québec-Océan, Département de Biologie, Université Laval, Québec, QC G1V 0A6, Canada
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20
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Ruus A, Øverjordet IB, Braaten HFV, Evenset A, Christensen G, Heimstad ES, Gabrielsen GW, Borgå K. Methylmercury biomagnification in an Arctic pelagic food web. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:2636-2643. [PMID: 26274519 DOI: 10.1002/etc.3143] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/02/2015] [Accepted: 06/25/2015] [Indexed: 06/04/2023]
Abstract
Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. The main objective of the present study was to quantify the biomagnification of MeHg in a marine pelagic food web, comprising species of zooplankton, fish, and seabirds, from the Kongsfjorden system (Svalbard, Norway), by use of trophic magnification factors. As expected, tissue concentrations of MeHg increased with increasing trophic level in the food web, though at greater rates than observed in several earlier studies, especially at lower latitudes. There was strong correlation between MeHg and total Hg concentrations through the food web as a whole. The concentration of MeHg in kittiwake decreased from May to October, contributing to seasonal differences in trophic magnification factors. The ecology and physiology of the species comprising the food web in question may have a large influence on the magnitude of the biomagnification. A significant linear relationship was also observed between concentrations of selenium and total Hg in birds but not in zooplankton, suggesting the importance of selenium in Hg detoxification for individuals with high Hg concentrations.
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Affiliation(s)
- Anders Ruus
- Norwegian Institute for Water Research, Oslo, Norway
| | - Ida B Øverjordet
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
- SINTEF Materials and Chemistry, Marine Environmental Technology, Trondheim, Norway
| | | | - Anita Evenset
- Akvaplan-niva, Fram Centre, Tromsø, Norway
- University of Tromsø, The Arctic University of Norway, Tromsø, Norway
| | | | | | | | - Katrine Borgå
- Norwegian Institute for Water Research, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
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21
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Freshwater discharges drive high levels of methylmercury in Arctic marine biota. Proc Natl Acad Sci U S A 2015; 112:11789-94. [PMID: 26351688 DOI: 10.1073/pnas.1505541112] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25-200%, overwhelming climate-driven changes over the next decade.
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22
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Shallow methylmercury production in the marginal sea ice zone of the central Arctic Ocean. Sci Rep 2015; 5:10318. [PMID: 25993348 PMCID: PMC4438723 DOI: 10.1038/srep10318] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 04/07/2015] [Indexed: 11/26/2022] Open
Abstract
Methylmercury (MeHg) is a neurotoxic compound that threatens wildlife and human health across the Arctic region. Though much is known about the source and dynamics of its inorganic mercury (Hg) precursor, the exact origin of the high MeHg concentrations in Arctic biota remains uncertain. Arctic coastal sediments, coastal marine waters and surface snow are known sites for MeHg production. Observations on marine Hg dynamics, however, have been restricted to the Canadian Archipelago and the Beaufort Sea (<79°N). Here we present the first central Arctic Ocean (79–90°N) profiles for total mercury (tHg) and MeHg. We find elevated tHg and MeHg concentrations in the marginal sea ice zone (81–85°N). Similar to other open ocean basins, Arctic MeHg concentration maxima also occur in the pycnocline waters, but at much shallower depths (150–200 m). The shallow MeHg maxima just below the productive surface layer possibly result in enhanced biological uptake at the base of the Arctic marine food web and may explain the elevated MeHg concentrations in Arctic biota. We suggest that Arctic warming, through thinning sea ice, extension of the seasonal sea ice zone, intensified surface ocean stratification and shifts in plankton ecodynamics, will likely lead to higher marine MeHg production.
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23
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Clayden MG, Arsenault LM, Kidd KA, O'Driscoll NJ, Mallory ML. Mercury bioaccumulation and biomagnification in a small Arctic polynya ecosystem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 509-510:206-215. [PMID: 25149682 DOI: 10.1016/j.scitotenv.2014.07.087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 06/03/2023]
Abstract
Recurring polynyas are important areas of biological productivity and feeding grounds for seabirds and mammals in the Arctic marine environment. In this study, we examined food web structure (using carbon and nitrogen isotopes, δ(13)C and δ(15)N) and mercury (Hg) bioaccumulation and biomagnification in a small recurring polynya ecosystem near Nasaruvaalik Island (Nunavut, Canada). Methyl Hg (MeHg) concentrations increased by more than 50-fold from copepods (Calanus hyperboreus) to Arctic terns (Sterna paradisaea), the abundant predators at this site. The biomagnification of MeHg through members of the food web - using the slope of log MeHg versus δ(15)N - was 0.157 from copepods (C. hyperboreus) to fish. This slope was higher (0.267) when seabird chicks were included in the analyses. Collectively, our results indicate that MeHg biomagnification is occurring in this small polynya and that its trophic transfer is at the lower end of the range of estimates from other Arctic marine ecosystems. In addition, we measured Hg concentrations in some poorly studied members of Arctic marine food webs [e.g. Arctic alligatorfish (Ulcina olrikii) and jellyfish, Medusozoa], and found that MeHg concentrations in jellyfish were lower than expected given their trophic position. Overall, these findings provide fundamental information about food web structure and mercury contamination in a small Arctic polynya, which will inform future research in such ecosystems and provide a baseline against which to assess changes over time resulting from environmental disturbance.
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Affiliation(s)
- Meredith G Clayden
- Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5, Canada.
| | - Lilianne M Arsenault
- Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5, Canada; Department of Earth and Environmental Science, Acadia University, Wolfville, NS B4P 2R6, Canada; Department of Biology, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Karen A Kidd
- Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5, Canada
| | - Nelson J O'Driscoll
- Department of Earth and Environmental Science, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Mark L Mallory
- Department of Biology, Acadia University, Wolfville, NS B4P 2R6, Canada
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Loseto LL, Stern GA, Macdonald RW. Distant drivers or local signals: where do mercury trends in western Arctic belugas originate? THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 509-510:226-236. [PMID: 25442642 DOI: 10.1016/j.scitotenv.2014.10.110] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 10/30/2014] [Accepted: 10/30/2014] [Indexed: 06/04/2023]
Abstract
Temporal trends of contaminants are monitored in Arctic higher trophic level species to inform us on the fate, transport and risk of contaminants as well as advise on global emissions. However, monitoring mercury (Hg) trends in species such as belugas challenge us, as their tissue concentrations reflect complex interactions among Hg deposition and methylation, whale physiology, dietary exposure and foraging patterns. The Beaufort Sea beluga population showed significant increases in Hg during the 1990 s; since that time an additional 10 years of data have been collected. During this time of data collection, changes in the Arctic have affected many processes that underlie the Hg cycle. Here, we examine Hg in beluga tissues and investigate factors that could contribute to the observed trends after removing the effect of age and size on Hg concentrations and dietary factors. Finally, we examine available indicators of climate variability (Arctic Oscillation (AO), the Pacific Decadal Oscillation (PDO) and sea-ice minimum (SIM) concentration) to evaluate their potential to explain beluga Hg trends. Results reveal a decline in Hg concentrations from 2002 to 2012 in the liver of older whales and the muscle of large whales. The temporal increases in Hg in the 1990 s followed by recent declines do not follow trends in Hg emission, and are not easily explained by diet markers highlighting the complexity of feeding, food web dynamics and Hg uptake. Among the regional-scale climate variables the PDO exhibited the most significant relationship with beluga Hg at an eight year lag time. This distant signal points us to consider beluga winter feeding areas. Given that changes in climate will impact ecosystems; it is plausible that these climate variables are important in explaining beluga Hg trends. Such relationships require further investigation of the multiple connections between climate variables and beluga Hg.
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Affiliation(s)
- L L Loseto
- Freshwater Institute/Fisheries and Oceans Canada, 501 University Cres., Winnipeg, MB R3T 2N6, Canada; Dept of Environment & Geography, University of Manitoba, 500 University Cres., Winnipeg, MB R3T 2N2, Canada.
| | - G A Stern
- Dept of Environment & Geography, University of Manitoba, 500 University Cres., Winnipeg, MB R3T 2N2, Canada
| | - R W Macdonald
- Dept of Environment & Geography, University of Manitoba, 500 University Cres., Winnipeg, MB R3T 2N2, Canada; Institute of Ocean Sciences, Fisheries and Oceans Canada, 9860 West Saanich Rd, Sidney, BC V8L 4B2, Canada
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