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Ahmed A, Aschner M, Ferrer B. JAK2/STAT3 signaling pathway mediates methylmercury toxicity in mouse astrocyte neuronal C8-D1A cell line. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.13.603400. [PMID: 39071366 PMCID: PMC11275743 DOI: 10.1101/2024.07.13.603400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Methylmercury (MeHg) is an environmental pollutant. Consumption of contaminated fish is the main exposure route in humans, leading to severe neurological disorders. Upon ingestion MeHg reaches the brain and selectively accumulates in astrocytes disrupting glutamate and calcium homeostasis and increasing oxidative stress. Despite extensive research, the molecular mechanisms underlying MeHg neurotoxicity remain incompletely understood. The induction of nuclear factor erythroid 2-related factor 2 (Nrf2) and its role activating antioxidant responses during MeHg-induced oxidative injury have garnered significant attention as a potential therapeutic target against MeHg toxicity. However, recent studies indicate that the Nrf2 signaling pathway alone may not be sufficient to mitigate MeHg-induced damage, suggesting the existence of other protective mechanisms. The signal transducer and activator of transcription 3 (STAT3) plays a crucial role in cell growth and survival. Several studies have also highlighted its involvement in regulating redox homeostasis, thereby preventing oxidative stress through mechanisms that involve modulation of nuclear genes that encode electron transport complexes (ETC) and antioxidant enzymes. These characteristics suggest that STAT3 could serve as a viable mechanism to mitigate MeHg toxicity, either in conjunction with or as an alternative to Nrf2 signaling. Our previous findings demonstrated that MeHg activates the STAT3 signaling pathway in the GT1-7 hypothalamic neuronal cell line, suggesting its potential role in promoting neuroprotection. Here, to elucidate the role of the STAT3 signaling pathway in MeHg neurotoxicity, we pharmacologically inhibited STAT3 using AG490 in the C8D1A astrocytic cell line exposed to 10 µM MeHg. Our data demonstrated that pharmacological inhibition of STAT3 phosphorylation exacerbates MeHg-induced mortality, antioxidant responses, and ROS production, suggesting that STAT3 may contribute to neuroprotection against MeHg exposure in astrocytes.
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Li K, Ying J, Liu T, Tian A, Wang X. A series of viologen complexes containing thiophene and Br - dual fluorescent chromophores for continuous visual sensing of pH and Hg 2. Dalton Trans 2024; 53:2741-2748. [PMID: 38226649 DOI: 10.1039/d3dt03415a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The mercury ion (Hg2+) is a typical high-toxicity substance that can cause severe damage to the environment and human bodies. For the detection of Hg2+, there are still significant challenges in the detection range and limit of detection (LOD). In this study, three viologen-based fluorescent probes are developed, CdCl4(Btybipy) (1), ZnBr4(Btybipy) (2), CdBr4(Btybipy) (3) (Btybipy = bis-1-thiophen-3-ylmethyl-[4,4']-bipyridinyl) through conventional solvent methods for detecting pH and Hg2+. Reversible discoloration and fluorescence response behaviour in the pH range of 4-12.8 is demonstrated by viologen-based fluorescent probes, which exhibit "ON-OFF-ON" signal changes. Compared with complex 1, it is surprising to find that complexes 2-3 display both fluorescence enhancement and fluorescence quenching simultaneously with the addition of different concentrations of Hg2+ (0-20 and 25-400 μM). There is broad linearity in the range of 0-20 and 50-300 μM with LODs of 2.14 and 3.13 nM, respectively. This occurrence of dual-signal modes is attributed to the participation of Br- and the thiophene S atom as dual chromophores in the coordination reaction of Hg2+. Dual-signal mode output, high sensitivity, wide detection range, and low LODs are exhibited by these fluorescent probes. The unique coordination reaction between Br- and the thiophene S atom with Hg2+ can provide a potential strategy for the exploitation of promising sensing platforms for monitoring Hg2+.
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Affiliation(s)
- Kai Li
- College of Chemistry and Materials Engineering, Bohai University, Jinzhou 121013, China.
| | - Jun Ying
- College of Chemistry and Materials Engineering, Bohai University, Jinzhou 121013, China.
| | - Tao Liu
- College of Sciences, North China University of Science and Technology, Tangshan, Hebei 063210, China.
| | - Aixiang Tian
- College of Chemistry and Materials Engineering, Bohai University, Jinzhou 121013, China.
| | - Xiuli Wang
- College of Chemistry and Materials Engineering, Bohai University, Jinzhou 121013, China.
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3
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Willacker JJ, Eagles-Smith CA, Nelson SJ, Flanagan Pritz CM, Krabbenhoft DP. The influence of short-term temporal variability on the efficacy of dragonfly larvae as mercury biosentinels. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161469. [PMID: 36632899 DOI: 10.1016/j.scitotenv.2023.161469] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Mercury (Hg) exposure to fish, wildlife, and humans is widespread and of global concern, thus stimulating efforts to reduce emissions. Because the relationships between rates of inorganic Hg loading, methylmercury (MeHg) production, and bioaccumulation are extremely complex and challenging to predict, there is a need for reliable biosentinels to understand the distribution of Hg in the environment and monitor the effectiveness of reduction efforts. However, it is important to assess how temporal and spatial variation at multiple scales influences the efficacy of specific biosentinels. Seasonal and interannual variation in total Hg (THg) concentrations of dragonfly larvae were examined in relation to spatial variability among 21 sites in two U.S. national parks with contrasting ecologies and Hg deposition patterns. Dragonfly THg differed among sampling events at 17 of the 21 sites, but by an average of only 20.4 % across events, compared to an average difference of 52.7 % among sites. Further, THg concentrations did not follow consistent seasonal patterns across sites or years, suggesting that the observed temporal variation was unlikely to bias monitoring efforts. Importantly, for a specific site, there was no difference in % MeHg in dragonflies among sampling events. Finally, there was significant temporal variability in the biogeochemical factors (aqueous inorganic Hg, aqueous MeHg, DOC, SO4, and pH) influencing dragonfly THg, with the importance of individual factors varying by 2.4 to 4.3-fold across sampling events. Despite these results, it is noteworthy that the observed temporal variation in dragonfly THg concentrations was neither large nor consistent enough to bias spatial assessments. Thus, although this temporal variation may provide insights into the processes influencing biological Hg concentrations, it is unlikely to impair the use of dragonflies as biosentinels for monitoring spatial or temporal patterns at scales relevant to most mitigation efforts.
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Affiliation(s)
- James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA.
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
| | - Sarah J Nelson
- Appalachian Mountain Club, 361 Route 16, Gorham, NH 03581, USA
| | | | - David P Krabbenhoft
- U.S. Geological Survey, Upper Midwest Water Science Center, 1 Gifford Pinchot Dr, Madison, WI 53726, USA
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Drenner RW, Chumchal MM, Adams KJ, Seymour RD. Effect of Land Cover on Ecoregion-Scale Spatial Patterns of Mercury Contamination of Largemouth Bass in the Southeastern United States. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:2386-2394. [PMID: 35975571 DOI: 10.1002/etc.5426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/03/2021] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Consumption of methylmercury (MeHg)-contaminated fish is the primary source of MeHg in humans and poses a hazard to human health. Because of widespread atmospheric deposition of inorganic mercury (IHg), all water bodies in the United States have been contaminated with Hg. In aquatic ecosystems, IHg is converted to MeHg, which biomagnifies, reaching high concentrations in piscivorous fish. It is not possible for governmental agencies to monitor fish from every waterbody to determine if concentrations of MeHg in fish are hazardous to human health. To help government agencies focus their monitoring efforts, it is critical that we develop the ability to predict regions where waterbodies are most likely to contain fish with hazardous concentrations of MeHg. The objective of the present study was to examine the relationship between MeHg contamination of largemouth bass (Micropterus salmoides), a popular piscivorous gamefish, and land cover in 24 ecoregions across 15 states in the southeastern United States. In our study we demonstrate for the first time that 72% of the variance in average concentrations of MeHg in largemouth bass between ecoregions of the southeastern United States can be explained by the percentage coverage by evergreen forests, emergent herbaceous wetlands, and pasture/hay. Land cover determines the sensitivity of freshwater systems to atmospheric IHg deposition, and the present study suggests that at the ecoregion scale, MeHg bioaccumulation in piscivorous gamefish, and ultimately the health hazard that these MeHg-contaminated fish pose to humans, can be in part predicted by land-cover type. Environ Toxicol Chem 2022;41:2386-2394. © 2022 SETAC.
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Affiliation(s)
- Ray W Drenner
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| | | | - Kimberly J Adams
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| | - Ryan D Seymour
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
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Hao Guo NW, Peng L, Chen Y, Liu Y, Li C, Zhang H, Yang W. A novel ratiometric fluorescence sensor based on lanthanide-functionalized MOF for Hg 2+ detection. Talanta 2022; 250:123710. [PMID: 35785609 DOI: 10.1016/j.talanta.2022.123710] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/15/2022] [Accepted: 06/22/2022] [Indexed: 10/17/2022]
Abstract
Post-synthesis modification is an effective strategy for the preparation of rare earth organic framework materials and the derivation of high-performance functional materials. Here, we report the preparation of a dual emission Ln-MOF material (Eu-Ca-MOF) using Ca-MOF as the parent framework and introducing Eu3+ ions into its channels through post-synthesis modification. Eu-Ca-MOF has good photoluminescence properties and can be used as a ratiometric fluorescence sensor (I381/I590) to detect Hg2+ ions in water sensitively. The characteristic of Eu-Ca-MOF obtained is that when the material is dispersed in an aqueous solution containing Hg2+ ions, the characteristic emission of the ligand at 381 nm is enhanced, while the characteristic emission of Eu3+ at 590 nm is quenched. The peak-to-height ratio of the two emissions can be used to achieve highly sensitive detection of Hg2+ ions even in the presence of other potentially competing analytes. In addition, Hg2+ induces Eu-Ca-MOF to produce a significant ratiometric luminescence response, which changes its luminescence color from red to blue, which is beneficial to visual analysis of naked eyes. At the same time, Eu-Ca-MOF has a wider detection range (0.02-200 μM), and a lower limit detection (2.6 nM) for Hg2+ ions. The lanthanide compounds prepared by post-synthetic modification provide an effective synthesis strategy for photoluminescent materials.
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Affiliation(s)
- Ning Wu Hao Guo
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China.
| | - Liping Peng
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China
| | - Yuan Chen
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China
| | - Yinsheng Liu
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China
| | - Cuiliu Li
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China
| | - Hao Zhang
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China
| | - Wu Yang
- Key Lab of Eco-Environments Related Polymer Materials of MOE, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China.
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Wu N, Guo H, Wang M, Peng L, Chen Y, Liu B, Pan Z, Liu Y, Yang W. A ratiometric sensor for selective detection of Hg 2+ ions by combining second-order scattering and fluorescence signals of MIL-68(In)-NH 2. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 270:120858. [PMID: 35016060 DOI: 10.1016/j.saa.2022.120858] [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: 10/04/2021] [Revised: 12/26/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
Ratio fluorescence has attracted much attention because of its self-calibration properties. However, it is difficult to obtain suitable fluorescent materials with well-resolved signals simultaneously under one excitation. In this work, we report a different strategy, using MIL-68(In)-NH2 as both the fluorescence element and the scattered light unit, and coupling the fluorescence and the scattered light to construct the fluorescence and scattered light ratio system. Based on the optical properties and the second-order scattering (SOS) of the material nanoparticles, the synthesized MIL-68(In)-NH2 can be used to realize the ratio detection of Hg2+. Because the scattering intensity of small particle MIL-68(In)-NH2 is weak, SOS is not obvious. When Hg2+ is introduced the coordination reaction between the amino nitrogen atoms of MIL-68(In)-NH2 and Hg2+ make the particles larger, resulting in the decrease of fluorescence and the enhancement of SOS. As a result, a novel Hg2+ ratiometric detection method is developed by using the dual signal responses of the fluorescence and scattering. Under the optimal conditions (pH = 6, reaction time 5 min, room temperature, and the maximum excitation wavelength 365 nm), the linear range of the method is 0-100 μM, and the detection limit is 5.8 nM (Ksv = 9.89 × 109 M-1). In addition, the probe is successfully used to evaluate Hg2+ in actual water samples. Compared with the traditional method of recording only the fluorescence signal, the proposed fluorescence-scattering method provides a new strategy for the design of ratiometric sensors.
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Affiliation(s)
- Ning Wu
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Hao Guo
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China.
| | - Mingyue Wang
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Liping Peng
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Yuan Chen
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Bingqing Liu
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Zhilan Pan
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Yinsheng Liu
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China
| | - Wu Yang
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, PR China.
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Ma Y, Hobson KA, Kardynal KJ, Guglielmo CG, Branfireun BA. Inferring spatial patterns of mercury exposure in migratory boreal songbirds: Combining feather mercury and stable isotope (δ 2H) measurements. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143109. [PMID: 33162143 DOI: 10.1016/j.scitotenv.2020.143109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Migratory songbirds breeding in the Canadian Boreal forest are exposed to mercury (Hg), a potent neurotoxin that impairs avian health, however, the degree of exposure depends on many factors. As breeding grounds are geographically remote and vast, the measurement of Hg in individual birds is impractical particularly at large spatial scales. Here, we present a Canada-wide dataset of nearly 2000 migratory songbirds that were used to assess summer Hg exposure of 15 songbird species sampled during fall migration. We measured Hg concentrations in tail feathers and related those to dietary guild, geographic capture location, age, sex and probable breeding ground locations using feather δ2H. Overall mean (±SE) feather Hg concentration was 1.49 ± 0.03 μg/g (N = 1946): however, a clear geographic gradient in feather Hg concentrations emerged being highest in East and lowest in West. Dietary guild was the next strongest predictor of feather Hg with insectivorous songbirds in Eastern Canada at particular risk due to Hg exposure on summer breeding grounds. This broad-scale assessment of Hg exposure in migratory songbirds in Canada can be used to guide future studies on finer-scale determinants of Hg exposure in birds.
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Affiliation(s)
- Yanju Ma
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Keith A Hobson
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Science and Technology Branch, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Kevin J Kardynal
- Science and Technology Branch, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Christopher G Guglielmo
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Brian A Branfireun
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Centre for Environment and Sustainability, University of Western Ontario, London, Ontario, Canada.
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Chen Y, Tang J, Wang S, Zhang L. Ninhydrin-functionalized chitosan for selective removal of Pb(II) ions: Characterization and adsorption performance. Int J Biol Macromol 2021; 177:29-39. [PMID: 33607139 DOI: 10.1016/j.ijbiomac.2021.02.110] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/22/2021] [Accepted: 02/14/2021] [Indexed: 01/19/2023]
Abstract
A chitosan-based adsorbents (CS-Ninhydrin) was prepared by grafting ninhydrin for Pb(II) ions adsorption. SEM-EDS, XRD and FTIR analysis were used to characterize the synthesized CS-Ninhydrin. The static adsorption experiments showed that CS-Ninhydrin had a good removal rate for Pb(II) ions in a wide range of pH 3 to 7, quickly reached equilibrium (120 min) and had a higher adsorption capacity (196 mg/g). Pseudo second-order and Langmuir models showed that the adsorption process of Pb(II) by CS-Ninhydrin was a single-layer chemical adsorption. Temperature experiments showed that the reaction was a spontaneous exothermic process. In the wastewater experiment, CS-Ninhydrin showed an excellent selectivity to Pb(II) ions. The reusability of CS-Ninhydrin was perfect after five adsorption-desorption cycles. The main adsorption mechanism was the chelating and electrostatic action between N and O groups in CS-Ninhydrin and Pb(II) ions. Therefore, the new adsorbent CS-Ninhydrin was expected to promote the wide application of chitosan in Pb(II) adsorption.
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Affiliation(s)
- Yingbi Chen
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China
| | - Jiali Tang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China
| | - Shixing Wang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China.
| | - Libo Zhang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China.
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Bianchini K, Tozer DC, Alvo R, Bhavsar SP, Mallory ML. Drivers of declines in common loon (Gavia immer) productivity in Ontario, Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139724. [PMID: 32531589 DOI: 10.1016/j.scitotenv.2020.139724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/22/2020] [Accepted: 05/24/2020] [Indexed: 06/11/2023]
Abstract
Common loons (Gavia immer) are top predators that depend on lake food webs to successfully fledge chicks. Common loon reproductive success is consequently recognized as an important indicator of aquatic ecosystem health. Existing evidence points to long-term declines in productivity in portions of the common loon range; however, the reason for these declines is not well understood. Our objectives were to define underlying baseline patterns of loon reproductive success in Ontario, Canada, and to identify drivers of temporal changes in loon productivity. We analyzed 38 years of reproductive data from over 1500 lakes using data from the Canadian Lakes Loon Survey, a citizen science loon monitoring program managed by Birds Canada that has run annually in Ontario since 1981. Overall, we estimated a declining trend in common loon reproductive success of -0.10 six-week-old young per pair per year in Ontario between 1981 and 2018. We assessed the influence of 14 factors on loon reproductive success. We identified low pH and associated higher mercury as factors linked to loon productivity declines. We also demonstrated that lake area, longitude, and April temperatures can predict the number of six-week-old young per pair per year. We hypothesize that climate change-induced stress, acting through multiple interacting pathways involving mercury acidity, fish abundance, lake size, and geographic location, may account for declining loon productivity. These results will be important for focusing future research and conservation efforts to help understand and mitigate threats to common loon populations.
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Affiliation(s)
- Kristin Bianchini
- Long Point Waterfowl and Wetlands Research Program, Birds Canada, P.O. Box 160 (Courier: 115 Front Road), Port Rowan, Ontario N0E 1M0, Canada; Biology Department, Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada
| | - Douglas C Tozer
- Long Point Waterfowl and Wetlands Research Program, Birds Canada, P.O. Box 160 (Courier: 115 Front Road), Port Rowan, Ontario N0E 1M0, Canada.
| | - Robert Alvo
- 45 Holland Ave., Unit 210, Ottawa, Ontario K1Y 4S3, Canada
| | - Satyendra P Bhavsar
- Ontario Ministry of the Environment, Conservation and Parks, Toronto, Ontario M9P 3V6, Canada
| | - Mark L Mallory
- Biology Department, Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada
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10
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Willacker JJ, Eagles-Smith CA, Blazer VS. Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:459-484. [PMID: 32239332 DOI: 10.1007/s10646-020-02193-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/10/2020] [Indexed: 06/11/2023]
Abstract
Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood. We compiled fish Hg data from state monitoring programs and recent research efforts to address this knowledge gap and provide a comprehensive assessment of fish Hg concentrations in the watershed's freshwater habitats. The resulting dataset consisted of nearly 8000 total Hg (THg) concentrations from 600 locations. Across the watershed, fish THg concentrations spanned a 44-fold range, with mean concentrations varying by 2.6- and 8.8-fold among major sub-watersheds and individual 8-digit hydrological units, respectively. Although, mean THg concentrations tended to be moderate, fish frequently exceeded benchmarks for potential adverse health effects, with 45, 48, and 36% of all samples exceeding benchmarks for human, avian piscivore, and fish risk, respectively. Importantly, the percentage of fish exceeding these benchmarks was not uniform among species or locations. The variation in fish THg concentrations among species and sites highlights the roles of waterbody, landscape, and ecological processes in shaping broad patterns in Hg risk across the watershed. We outline an integrated Hg monitoring program that could identify key factors influencing Hg concentrations across the watershed and facilitate the implementation of management strategies to mitigate the risks posed by Hg.
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Affiliation(s)
- James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
| | - Vicki S Blazer
- U.S. Geological Survey, Leetown Science Center, National Fish Health Research Laboratory, 11649 Leetown Road, Kearneysville, WV, 25430, USA
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Eccles KM, Thomas PJ, Chan HM. Relationships between mercury concentrations in fur and stomach contents of river otter (Lontra canadensis) and mink (Neovison vison) in Northern Alberta Canada and their applications as proxies for environmental factors determining mercury bioavailability. ENVIRONMENTAL RESEARCH 2020; 181:108961. [PMID: 31806289 DOI: 10.1016/j.envres.2019.108961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 05/05/2023]
Abstract
The fur of piscivorous animals such as river otter (Lontra canadensis) and mink (Neovison vison) has been proposed to be used as a biomarker medium to assess mercury (Hg) exposure, but the relationship with dietary and environmental Hg exposure has not been fully characterized. The objective of this study was to investigate the relationship between fur total mercury (THg) and stomach content THg in river otter and mink, and their relationships with environmental factors. THg concentrations were measured in fur and stomach contents of river otter (n = 35) and mink (n = 30) collected from northern Alberta, Canada between 2014 and 2017. The fur THg concentration (mean ± standard deviation) was 6.36 ± 4.12 μg/g fur weight and 5.25 ± 3.50 μg/g fur weight and the average stomach content THg was 0.95 ± 0.56 μg/g dry weight and 0.71 ± 0.54 μg/g dry weight in river otter and mink respectively. There was a positive relationship between the log fur THg and log stomach contents THg for both species (p < 0.05). There was a positive relationship between the log THg of stomach contents and the percent of deciduous forest and a negative relationship with soil pH. There was a positive relationship between the log THg of fur and the total area burned by forest fire and a negative relationship with the percentage of wetlands. These results provide field evidence that fur can be used to reflect dietary Hg exposure and to identify sources and environmental factors that affect the bioavailable Hg in the habitats of these wildlife species.
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Affiliation(s)
- Kristin M Eccles
- Department of Biology, Collaborative Program in Chemical and Environmental Toxicology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
| | - Philippe J Thomas
- Department of Biology, Collaborative Program in Chemical and Environmental Toxicology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada; Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Center, 1125 Colonel By Drive, Raven Road, Ottawa, ON, K1A 0H3, Canada.
| | - Hing Man Chan
- Department of Biology, Collaborative Program in Chemical and Environmental Toxicology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
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Roberts S, Kirk JL, Wiklund JA, Muir DCG, Yang F, Gleason A, Lawson G. Mercury and metal(loid) deposition to remote Nova Scotia lakes from both local and distant sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 675:192-202. [PMID: 31030127 DOI: 10.1016/j.scitotenv.2019.04.167] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/08/2019] [Accepted: 04/11/2019] [Indexed: 06/09/2023]
Abstract
Kejimkujik National Park, in Nova Scotia, Canada, is a sensitive region for metal(loid) contamination, such as mercury, in part due to long-range atmospheric deposition from global and regional industrial centers. The region is remote from industrial centres, but is downwind of major pollution sources in the Eastern United States and Canada, and historically had numerous gold mining sites. Due to a paucity of long-term atmospheric deposition monitoring in this region, little is known about the response of Kejimkujik lakes to multiple changing global, regional and local atmospheric Hg and metal(loid) sources. Here, we used multiple lake sediment cores to reconstruct anthropogenic depositional fluxes of metal(loid)s of concern for the last ~210years. Results showed that Kejimkujik lake sediments are highly enriched in lead (Pb), antimony (Sb) and tin (Sn), with post-industrial metal(loid) concentrations being >4-fold greater than natural baseline levels (prior to ~1800) and moderately enriched in silver (Ag), bismuth (Bi), cadmium (Cd), copper (Cu), mercury (Hg), rubidium (Rb), tellurium (Te), thallium (Tl), vanadium (V), tungsten (W) and zinc (Zn), with post-industrial metal(loid) concentrations being between 1.5 and 4-fold greater than natural baseline levels (prior to ~1800). Lake sediment core reconstructions of total atmospheric Hg deposition matched well with Hg wet deposition monitoring data from the overlapped period (1997-2010) being 9.1±2.7μg/m2/yr and 7.0±0.7μg/m2/yr respectively. Lakes closest to historic gold mining sites show spikes in Ag, Cd, Sb, Tl, Zn and W during mining periods (~1880 and 1950). Most of the enriched metal(loid)s (EF >1.5) (Ag, Bi, Cu, Hg, Pb, Sb, Sn, V and W) do not appear affected by redox and remobilisation issues. For the other enriched metal(loid)s (EF >1.5) (Cd, Tl, and Zn), remobilisation from upper sediments appears to be occurring within these acidic and DOC rich Kejimkujik lakes.
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Affiliation(s)
- S Roberts
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada.
| | - J L Kirk
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada.
| | - J A Wiklund
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - D C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - F Yang
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - A Gleason
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
| | - G Lawson
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario L7R 4A6, Canada
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Fu L, Wang S, Lin G, Zhang L, Liu Q, Fang J, Wei C, Liu G. Post-functionalization of UiO-66-NH 2 by 2,5-Dimercapto-1,3,4-thiadiazole for the high efficient removal of Hg(II) in water. JOURNAL OF HAZARDOUS MATERIALS 2019; 368:42-51. [PMID: 30665107 DOI: 10.1016/j.jhazmat.2019.01.025] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 01/06/2019] [Accepted: 01/10/2019] [Indexed: 05/25/2023]
Abstract
A new MOFs adsorbent was prepared by post-functionalization of UiO-66-NH2 with 2,5-Dimercapto-1,3,4-thiadiazole and utilized to remove the Hg(II) in water selectively. The UiO-66-types were detected by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), Brunauer-Emmett-Teller (BET) and zeta potential instruments. The adsorption properties of the new MOFs adsorbent were investigated by batch experiments. The actual maximum adsorption amount was 670.5 mg/g at the optimal pH of 3. Adsorption kinetic and isotherm models were exceedingly fitted to pseudo-second-order and Langmuir/Dubinin-Radushkevich, respectively. The adsorption process and mode were geared to monolayer and chemisorption, the removal rate was directly proportional to the square of mercury ions concentration. The UiO-66-DMTD adsorbent was easy to be regenerated and the removal rate decreased by only 13.5% after ten consecutive cycles. The results of FTIR, XRD and XPS suggested that the adsorption mechanism lay on the complexation reaction between Hg(II) and thiol/nitrogen-containing groups. Moreover, compared with other competitive metal ions, viz., Zn(II), Co(IV), Ni(II), Cd(II), Mg(II), Fe(III), Ca(II) and Cu(II), the UiO-66-DMTD demonstrated an outstanding selective adsorption for Hg(II). These results manifested that the UiO-66-DMTD was a latent adsorbent for the efficient and selective removal of Hg(II) in wastewater.
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Affiliation(s)
- Likang Fu
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| | - Shixing Wang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Guo Lin
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Libo Zhang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Qiming Liu
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China.
| | - Ju Fang
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| | - Chenhuinan Wei
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| | - Gang Liu
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
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Gerstle CT, Drenner RW, Chumchal MM. Spatial patterns of mercury contamination and associated risk to piscivorous wading birds of the south central United States. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:160-166. [PMID: 30367697 DOI: 10.1002/etc.4299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/10/2018] [Accepted: 10/06/2018] [Indexed: 06/08/2023]
Abstract
Piscivorous birds are top predators in aquatic ecosystems and are vulnerable to mercury (Hg) exposure and associated adverse health effects. In some areas of North America, the health risk posed to piscivorous birds by Hg contamination has not been characterized because concentrations of Hg in bird tissues have not been extensively monitored. When data on Hg in tissues of piscivorous birds are not available, the concentration of Hg in the blood of piscivorous birds can be estimated from the concentration of Hg in prey fish. We used concentrations of Hg in different lengths of a proxy prey fish, bluegill (Lepomis macrochirus), to estimate the concentration of Hg in the blood of 4 species of adult piscivorous wading birds (little blue herons [Egretta caerulea], green herons [Butorides virescens], great egrets [Ardea albus], and great blue herons [Ardea herodias]) in 14 ecoregions of the south central United States. The 4 species of birds consume different sizes of fish with different concentrations of Hg and were predicted to have different concentrations of Hg in their blood, with little blue herons < green herons < great egrets < great blue herons. For each species of bird, there were significant differences in average estimated concentrations of Hg in blood between ecoregions, with estimated concentrations of Hg in blood increasing with Hg deposition. The level of predicted risk varied with ecoregion and bird species and was highest for great blue herons. We recommend that future studies of Hg contamination of piscivorous wading birds of the southern United States focus on great blue herons in water bodies within ecoregions that have high Hg deposition. Environ Toxicol Chem 2019;38:160-166. © 2018 SETAC.
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Affiliation(s)
| | - Ray W Drenner
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Matthew M Chumchal
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
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Chételat J, Hickey MBC, Poulain AJ, Dastoor A, Ryjkov A, McAlpine D, Vanderwolf K, Jung TS, Hale L, Cooke ELL, Hobson D, Jonasson K, Kaupas L, McCarthy S, McClelland C, Morningstar D, Norquay KJO, Novy R, Player D, Redford T, Simard A, Stamler S, Webber QMR, Yumvihoze E, Zanuttig M. Spatial variation of mercury bioaccumulation in bats of Canada linked to atmospheric mercury deposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:668-677. [PMID: 29396333 DOI: 10.1016/j.scitotenv.2018.01.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/05/2018] [Accepted: 01/06/2018] [Indexed: 06/07/2023]
Abstract
Wildlife are exposed to neurotoxic mercury at locations distant from anthropogenic emission sources because of long-range atmospheric transport of this metal. In this study, mercury bioaccumulation in insectivorous bat species (Mammalia: Chiroptera) was investigated on a broad geographic scale in Canada. Fur was analyzed (n=1178) for total mercury from 43 locations spanning 20° latitude and 77° longitude. Total mercury and methylmercury concentrations in fur were positively correlated with concentrations in internal tissues (brain, liver, kidney) for a small subset (n=21) of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), validating the use of fur to indicate internal mercury exposure. Brain methylmercury concentrations were approximately 10% of total mercury concentrations in fur. Three bat species were mainly collected (little brown bats, big brown bats, and northern long-eared bats [M. septentrionalis]), with little brown bats having lower total mercury concentrations in their fur than the other two species at sites where both species were sampled. On average, juvenile bats had lower total mercury concentrations than adults but no differences were found between males and females of a species. Combining our dataset with previously published data for eastern Canada, median total mercury concentrations in fur of little brown bats ranged from 0.88-12.78μg/g among 11 provinces and territories. Highest concentrations were found in eastern Canada where bats are most endangered from introduced disease. Model estimates of atmospheric mercury deposition indicated that eastern Canada was exposed to greater mercury deposition than central and western sites. Further, mean total mercury concentrations in fur of adult little brown bats were positively correlated with site-specific estimates of atmospheric mercury deposition. This study provides the largest geographic coverage of mercury measurements in bats to date and indicates that atmospheric mercury deposition is important in determining spatial patterns of mercury accumulation in a mammalian species.
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Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario K1A 0H3, Canada.
| | | | - Alexandre J Poulain
- Biology Department, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Ashu Dastoor
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, Quebec H9P 1J3, Canada
| | - Andrei Ryjkov
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, Quebec H9P 1J3, Canada
| | - Donald McAlpine
- New Brunswick Museum, Saint John, New Brunswick E2K 1E5, Canada
| | - Karen Vanderwolf
- New Brunswick Museum, Saint John, New Brunswick E2K 1E5, Canada; Canadian Wildlife Federation, Kanata, Ontario K2M 2W1, Canada
| | - Thomas S Jung
- Yukon Department of Environment, Whitehorse, Yukon Territory Y1A 2C6, Canada
| | - Lesley Hale
- Ontario Ministry of Natural Resources & Forestry, Peterborough, Ontario K9J 8M5, Canada
| | - Emma L L Cooke
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario K1A 0H3, Canada
| | - Dave Hobson
- Alberta Environment and Parks, Edson, Alberta T7E 1T2, Canada
| | - Kristin Jonasson
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
| | - Laura Kaupas
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Sara McCarthy
- Wildlife Division, Fisheries and Land Resources, Goose Bay, Newfoundland and Labrador A0P 1E0, Canada
| | - Christine McClelland
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario K1A 0H3, Canada
| | | | - Kaleigh J O Norquay
- Department of Biology, University of Winnipeg, Winnipeg, Manitoba R3B 2G3, Canada
| | - Richard Novy
- Golder Associates Ltd., Calgary, Alberta T2A 7W5, Canada
| | | | - Tony Redford
- Animal Health Centre, BC Ministry of Agriculture, Abbotsford, British Columbia V3G 2M3, Canada
| | - Anouk Simard
- Direction de l'expertise sur la faune terrestre, l'herpétofaune et l'avifaune, Ministère des Forêts, de la Faune et des Parcs, Québec, Quebec G1S 4X4, Canada
| | - Samantha Stamler
- Alberta Environment and Parks, Edmonton, Alberta T6H 4P2, Canada
| | - Quinn M R Webber
- Department of Biology, University of Winnipeg, Winnipeg, Manitoba R3B 2G3, Canada
| | - Emmanuel Yumvihoze
- Biology Department, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Michelle Zanuttig
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario K1A 0H3, Canada
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Silverthorn VM, Bishop CA, Jardine T, Elliott JE, Morrissey CA. Impact of flow diversion by run-of-river dams on American dipper diet and mercury exposure. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:411-426. [PMID: 29092091 DOI: 10.1002/etc.3961] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/13/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
Run-of-river dams produce lower greenhouse gas emissions than large hydropower projects, but there is a paucity of research on their potential ecotoxicological impacts through disruption of natural flow regimes. We used stable isotopes (δ13 C, δ15 N, δ34 S) to reconstruct diet and trace methylmercury in a predatory river-resident passerine, the American dipper (Cinclus mexicanus), at 7 regulated and 6 free-flowing mountain streams in coastal British Columbia, Canada. Assimilated diets were comparable among regulated and unregulated streams, dominated by benthic macroinvertebrates and resident freshwater fish, with negligible contributions from anadromous Pacific salmon. Although invertebrates at unregulated streams were isotopically similar along their gradient, dippers and invertebrates sampled below dams on regulated streams had 34 S-depleted tissues, suggesting increased activity of sulfate-reducing bacteria and more Hg methylation below the dams. Mercury concentrations in dipper blood (417.6 ± 74.1 standard error [SE] ng/g wet wt at regulated streams, 340.7 ± 42.7 SE ng/g wet wt at unregulated streams) and feathers (1564 .6 ± 367.2 SE ng/g dry wt regulated, 1149.0 ± 152.1 SE ng/g dry wt unregulated), however, were not significantly different between stream types. Relative to other passerines across western North America, dippers in these densely forested mountain streams experienced high mercury exposure; and one recently regulated stream supported dippers with mercury concentrations of potential toxicity concern (up to 8459.5 ng/g dry wt in feathers and 1824.6 ng/g wet wt in whole blood). Elevated mercury in dippers is likely attributable to the birds' relatively high trophic position and high regional inorganic mercury deposition; however, biogeochemical conditions in reservoirs of some regulated streams may be contributing to methylmercury production. Environ Toxicol Chem 2018;37:411-426. © 2017 SETAC.
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Affiliation(s)
| | - Christine A Bishop
- Environment and Climate Change Canada, Wildlife and Landscape Science Division, Delta, British Columbia, Canada
| | - Timothy Jardine
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - John E Elliott
- Environment and Climate Change Canada, Wildlife and Landscape Science Division, Delta, British Columbia, Canada
| | - Christy A Morrissey
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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17
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Stafford CP, Downs CC, Langner HW. Mercury Hazard Assessment for Piscivorous Wildlife in Glacier National Park. NORTHWEST SCIENCE 2016. [DOI: 10.3955/046.090.0406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Scheuhammer AM, Lord SI, Wayland M, Burgess NM, Champoux L, Elliott JE. Major correlates of mercury in small fish and common loons (Gavia immer) across four large study areas in Canada. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 210:361-370. [PMID: 26803793 DOI: 10.1016/j.envpol.2016.01.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 06/05/2023]
Abstract
We investigated mercury (Hg) concentrations in small fish (mainly yellow perch, Perca flavescens; ∼60% of fish collected) and in blood of common loons (Gavia immer) that prey upon them during the breeding season on lakes in 4 large, widely separated study areas in Canada (>13 lakes per study area; total number of lakes = 93). Although surface sediments from lakes near a base metal smelter in Flin Flon, Manitoba had the highest Hg concentrations, perch and other small fish and blood of common loon chicks sampled from these same lakes had low Hg concentrations similar to those from uncontaminated reference lakes. Multiple regression modeling with AIC analysis indicated that lake pH was by far the most important single factor influencing perch Hg concentrations in lakes across the four study areas (R(2) = 0.29). The best model was a three-variable model (pH + alkalinity + sediment Se; Wi = 0.61, R(2) = 0.85). A single-variable model (fish Hg) best explained among-lake variability in loon chick blood Hg (Wi = 0.17; R(2) = 0.53). From a toxicological risk perspective, all lakes posing a potential Hg health risk for perch and possibly other small pelagic fish species (where mean fish muscle Hg concentrations exceeded 2.4 μg/g dry wt.), and for breeding common loons (where mean fish muscle Hg concentrations exceeded 0.8 μg/g dry wt., and loon chick blood Hg exceeded 1.4 μg/g dry wt.) had pH < 6.7 and were located in eastern Canada.
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Affiliation(s)
- A M Scheuhammer
- Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Ottawa, Ontario, K1A 0H3, Canada.
| | - S I Lord
- University of Waterloo, Department of Biology, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada
| | - M Wayland
- Environment and Climate Change Canada, 115 Perimeter Rd, Saskatoon, SK, S7N 0X4, Canada
| | - N M Burgess
- Environment and Climate Change Canada, 6 Bruce St, Mount Pearl, NL, A1N 4T3, Canada
| | - L Champoux
- Environment and Climate Change Canada, 1550 avenue D'Estimauville, QC, G1J 0C3, Canada
| | - J E Elliott
- Environment and Climate Change Canada, 5421 Robertson Rd, Delta, BC, V4K 3N2, Canada
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Little ME, Burgess NM, Broders HG, Campbell LM. Distribution of mercury in archived fur from little brown bats across Atlantic Canada. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 207:52-58. [PMID: 26340299 DOI: 10.1016/j.envpol.2015.07.049] [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: 04/02/2015] [Revised: 07/18/2015] [Accepted: 07/28/2015] [Indexed: 06/05/2023]
Abstract
Total mercury (Hg) concentrations were measured in archived fur from adult female little brown bats sampled at maternity roosts across Atlantic Canada. Mercury concentrations varied significantly among regions and roosts. Bats from Nova Scotia and Newfoundland had the highest median Hg concentrations (9.67 μg/g and 9.51 μg/g) among regions, and individuals from Kejimkujik National Park had the highest Hg (median: 28.38 μg/g) among roosts. Over one third of individuals sampled had fur Hg concentrations exceeding thresholds associated with neurochemical responses. Within-roost examinations of stable carbon and nitrogen isotopes in fur showed inconsistent associations with Hg concentrations. Therefore, the hypothesis that within-roost variation in Hg is driven by variation in diet is not supported by this data, and it is recommended that key prey items be included in future mercury bioaccumulation studies for bats. The elevated mercury fur concentrations for bats from southern Nova Scotia remains an anomaly of concern even when placed in the larger context of Atlantic Canada.
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Affiliation(s)
- Megan E Little
- Environmental Science, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia B3H 3C3, Canada
| | - Neil M Burgess
- Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment Canada, Mount Pearl, Newfoundland & Labrador A1N 4T3, Canada
| | - Hugh G Broders
- Biology Department, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia B3H 3C3, Canada
| | - Linda M Campbell
- Environmental Science, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia B3H 3C3, Canada.
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Rolfhus KR, Wiener JG, Haro RJ, Sandheinrich MB, Bailey SW, Seitz BR. Mercury in streams at Grand Portage National Monument (Minnesota, USA): assessment of ecosystem sensitivity and ecological risk. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 514:192-201. [PMID: 25666279 DOI: 10.1016/j.scitotenv.2015.01.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/23/2015] [Accepted: 01/24/2015] [Indexed: 06/04/2023]
Abstract
Mercury (Hg) in water, sediment, soils, seston, and biota were quantified for three streams in the Grand Portage National Monument (GRPO) in far northeastern Minnesota to assess ecosystem contamination and the potential for harmful exposure of piscivorous fish, wildlife, and humans to methylmercury (MeHg). Concentrations of total Hg in water, sediment, and soil were typical of those in forest ecosystems within the region, whereas MeHg concentrations and percent MeHg in these ecosystem components were markedly higher than values reported elsewhere in the western Great Lakes Region. Soils and sediment were Hg-enriched, containing approximately 4-fold more total Hg per unit of organic matter. We hypothesized that localized Hg enrichment was due in part to anthropogenic pollution associated with historic fur-trading activity. Bottom-up forcing of bioaccumulation was evidenced by MeHg concentrations in larval dragonflies, which were near the maxima for dragonflies sampled concurrently from five other national park units in the region. Despite its semi-remote location, GRPO is a Hg-sensitive landscape in which MeHg is produced and bioaccumulated in aquatic food webs to concentrations that pose ecological risks to MeHg-sensitive piscivores, including predatory fish, belted kingfisher, and mink.
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Affiliation(s)
- Kristofer R Rolfhus
- University of Wisconsin-La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA.
| | - James G Wiener
- University of Wisconsin-La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA.
| | - Roger J Haro
- University of Wisconsin-La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA.
| | - Mark B Sandheinrich
- University of Wisconsin-La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA.
| | - Sean W Bailey
- University of Wisconsin-La Crosse, River Studies Center, 1725 State Street, La Crosse, WI 54601, USA.
| | - Brandon R Seitz
- National Park Service, Grand Portage National Monument, P.O. Box 426, 170 Mile Creek Road, Grand Portage, MN 55605, USA.
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