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Chételat J, Jung TS, Awan M, Baryluk S, Harrower W, Kukka PM, McClelland C, Mowat G, Pelletier N, Rodford C, Stimmelmayr R. Tissue Distribution and Toxicological Risk Assessment of Mercury and Other Elements in Northern Populations of Wolverine (Gulo gulo). ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2024:10.1007/s00244-024-01081-x. [PMID: 39097543 DOI: 10.1007/s00244-024-01081-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 07/16/2024] [Indexed: 08/05/2024]
Abstract
Wolverines are facultative scavengers that feed near the top of terrestrial food chains. We characterized concentrations of mercury and other trace elements in tissues of wolverine from a broad geographic area, representing much of their contemporary distribution in northwestern North America. We obtained tissues from 504 wolverines, from which mercury was measured on muscle (n = 448), kidney (n = 222), liver (n = 148), hair (n = 130), and brain (n = 52). In addition, methylmercury, seven trace elements (arsenic, cadmium, chromium, cobalt, lead, nickel, selenium), and arsenic compounds were measured on a subset of samples. Concentrations of mercury and other trace elements varied between tissues and were generally highest in kidney compared to brain, liver and muscle. Mercury was predominately as methylmercury in brain and muscle, but largely as inorganic mercury in liver and kidney. Mercury concentrations of hair were moderately correlated with those of internal tissues (Pearson r = 0.51-0.75, p ≤ 0.004), making hair a good non-lethal indicator of broad spatial or temporal differences in mercury exposure to wolverine. Arsenobetaine was the dominant arsenic compound identified in tissues, and arsenite, arsenocholine and dimethylarsinic acid were also detected. A preliminary risk assessment suggested the cadmium, lead, mercury, and selenium concentrations in our sample of wolverines were not likely to pose a risk of overt toxicological effects. This study generated a comprehensive dataset on mercury and other trace elements in wolverine, which will support future contaminants study of this northern terrestrial carnivore.
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Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada.
| | - Thomas S Jung
- Department of Environment, Government of Yukon, Whitehorse, YT, Canada
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Malik Awan
- Department of Environment, Government of Nunavut, Arviat, NU, Canada
| | - Steven Baryluk
- Environment and Climate Change, Government of the Northwest Territories, Inuvik, NT, Canada
| | - William Harrower
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Piia M Kukka
- Department of Environment, Government of Yukon, Whitehorse, YT, Canada
| | - Christine McClelland
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
| | - Garth Mowat
- Ministry of Forests, Government of British Columbia, Nelson, BC, Canada
- Department of Earth, Environmental and Geographic Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Nicolas Pelletier
- Department of Geography and Environmental Studies, Carleton University, Ottawa, ON, Canada
| | - Christine Rodford
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
| | - Raphaela Stimmelmayr
- Department of Wildlife Management, North Slope Borough, Utqiagvik, AK, USA
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
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2
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Eccles KM, Boutet V, Branigan M, Dyck M, van Coeverden de Groot P, Lougheed SC, Rutter A, Langlois VS. Non-invasive biomonitoring of polar bear feces can be used to estimate concentrations of metals of concern in traditional food. PLoS One 2024; 19:e0305398. [PMID: 38917117 PMCID: PMC11198741 DOI: 10.1371/journal.pone.0305398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
The Arctic faces increasing exposure to environmental chemicals such as metals, posing health risks to humans and wildlife. Biomonitoring of polar bears (Ursus maritimus) can be used to quantify chemicals in the environment and in traditional foods consumed by the Inuit. However, typically, these samples are collected through invasive or terminal methods. The biomonitoring of feces could be a useful alternative to the current metal monitoring method within the Arctic. Here, we aim to 1) quantify the relationship between concentrations of metals in the feces and tissues (muscle, liver, and fat) of polar bears using predictive modeling, 2) develop an easy-to-use conversion tool for use in community-based monitoring programs to non-invasively estimate contaminant concentrations in polar bears tissues and 3) demonstrate the application of these models by examining potential exposure risk for humans from consumption of polar bear muscle. Fecal, muscle, liver, and fat samples were harvested from 49 polar bears through a community-based monitoring program. The samples were analyzed for 32 metals. Exploratory analysis indicated that mean metal concentrations generally did not vary by age or sex, and many of the metals measured in feces were positively correlated with the internal tissue concentration. We developed predictive linear regression models between internal (muscle, liver, fat) and external (feces) metal concentrations and further explored the mercury and methylmercury relationships for utility risk screening. Using the cross-validated regression coefficients, we developed a conversion tool that contributes to the One Health approach by understanding the interrelated health of humans, wildlife, and the environment in the Arctic. The findings support using feces as a biomonitoring tool for assessing contaminants in polar bears. Further research is needed to validate the developed models for other regions in the Arctic and assess the impact of environmental weathering on fecal metal concentrations.
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Affiliation(s)
- Kristin M. Eccles
- Environmental Health Science and Research Bureau, Health Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada
| | - Vincent Boutet
- Institut National de la Recherche Scientifique (INRS), Québec, Canada
| | - Marsha Branigan
- Government of the Northwest Territories, Yellowknife, Canada
| | - Markus Dyck
- Government of Nunavut, Department of Environment, Igloolik, NU, Canada
| | | | | | - Allison Rutter
- School of Environmental Studies, Queen’s University, Kingston, ON, Canada
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Warret Rodrigues C, Armstrong D, Wang F, Roth JD. Tissue composition and storage duration affect the usefulness of generic wet-to-dry mass conversion factors in toxicology studies. ENVIRONMENTAL RESEARCH 2023; 236:116727. [PMID: 37495068 DOI: 10.1016/j.envres.2023.116727] [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: 03/22/2023] [Revised: 06/24/2023] [Accepted: 07/22/2023] [Indexed: 07/28/2023]
Abstract
All ecosystems are exposed to a variety of anthropogenic contaminants. The potential threat posed by these contaminants to organisms has prompted scores of toxicology studies. Contaminant concentrations in wildlife toxicology studies are inconsistently expressed in wet or dry mass units, or even on a lipid-normalized basis, but tissue composition is rarely reported, and the conversion between dry and wet mass units, notably, is often based on assumed empirical moisture contents in tissues. However, diverse factors (e.g., tissue, storage conditions) may affect tissue composition and render comparisons between studies difficult or potentially biased. Here, we used data on the concentration of mercury, a global pollutant, in tissues of red foxes (Vulpes vulpes) to quantify the effects of diverse variables on moisture and lipid contents, and their consequences on contaminant concentration in different tissues, when converting between wet and dry mass units (lipid extracted or not). We found that moisture content differed largely between organs, enough to preclude the use of a single conversion factor, and decreased by 1% per year when stored at -80 °C. Although most fox tissues had low lipid concentrations, lipid content affected water content and their extraction affected the wet to dry mass conversion factor. We thus recommend reporting tissue composition (at least water and lipid contents) systematically in toxicology studies of mercury specifically and of contaminants in general, and using tissue/species specific conversion factors to convert between dry and wet mass concentration.
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Affiliation(s)
- Chloé Warret Rodrigues
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba R3T 2N2, Canada.
| | - Debbie Armstrong
- Centre for Earth Observation Science, And Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Feiyue Wang
- Centre for Earth Observation Science, And Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - James D Roth
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba R3T 2N2, Canada
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4
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Adams EM, Gulka JE, Yang Y, Burton MEH, Burns DA, Buxton V, Cleckner L, DeSorbo CR, Driscoll CT, Evers DC, Fisher N, Lane O, Mao H, Riva-Murray K, Millard G, Razavi NR, Richter W, Sauer AK, Schoch N. Distribution and trends of mercury in aquatic and terrestrial biota of New York, USA: a synthesis of 50 years of research and monitoring. ECOTOXICOLOGY (LONDON, ENGLAND) 2023; 32:959-976. [PMID: 37861861 DOI: 10.1007/s10646-023-02704-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/02/2023] [Indexed: 10/21/2023]
Abstract
Mercury (Hg) inputs have particularly impacted the northeastern United States due to its proximity to anthropogenic emissions sources and abundant habitats that efficiently convert inorganic Hg into methylmercury. Intensive research and monitoring efforts over the past 50 years in New York State, USA, have informed the assessment of the extent and impacts of Hg exposure on fishes and wildlife. By synthesizing Hg data statewide, this study quantified temporal trends of Hg exposure, spatiotemporal patterns of risk, the role that habitat and Hg deposition play in producing spatial patterns of Hg exposure in fish and other wildlife, and the effectiveness of current monitoring approaches in describing Hg trends. Most temporal trends were stable, but we found significant declines in Hg exposure over time in some long-sampled fish. The Adirondack Mountains and Long Island showed the greatest number of aquatic and terrestrial species with elevated Hg concentrations, reflecting an unequal distribution of exposure risk to fauna across the state. Persistent hotspots were detected for aquatic species in central New York and the Adirondack Mountains. Elevated Hg concentrations were associated with open water, forests, and rural, developed habitats for aquatic species, and open water and forested habitats for terrestrial species. Areas of consistently elevated Hg were found in areas driven by atmospheric and local Hg inputs, and habitat played a significant role in translating those inputs into biotic exposure. Continued long-term monitoring will be important in evaluating how these patterns continue to change in the face of changing land cover, climate, and Hg emissions.
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Affiliation(s)
- Evan M Adams
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA.
| | - Julia E Gulka
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Yang Yang
- Western Carolina University, 1 University Way, Cullowhee, NC, 28723, USA
| | - Mark E H Burton
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Douglas A Burns
- USGS New York Water Science Center, 425 Jordan Road, Troy, NY, 12180, USA
| | - Valerie Buxton
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, 2125 Derring Hall, 926 West Campus Drive, Blacksburg, VA, 24061, USA
- Adirondack Center for Loon Conservation, PO Box 195, Ray Brook, NY, 12977, USA
| | - Lisa Cleckner
- Finger Lakes Institute, 601 South Maine Street, Geneva, NY, 14456, USA
- Hobart and William Smith Colleges, 300 Pulteney St., Geneva, NY, 14456, USA
| | | | - Charles T Driscoll
- Syracuse University, Department of Civil and Environmental Engineering, 151 Link Hall, Syracuse, NY, 13244, USA
| | - David C Evers
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Nicholas Fisher
- Stony Brook University, School of Marine and Atmospheric Sciences, 100 Nicolls Road, Stony, NY, 11794, USA
| | - Oksana Lane
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Huiting Mao
- SUNY-ESF Chemistry Department, 1 Forestry Derive, Syracuse, NY, 13210, USA
| | - Karen Riva-Murray
- USGS New York Water Science Center, 425 Jordan Road, Troy, NY, 12180, USA
| | - Geoffrey Millard
- Syracuse University, Department of Civil and Environmental Engineering, 151 Link Hall, Syracuse, NY, 13244, USA
- U.S.A. Environmental Protection Agency, Office of Research and Development, 26 W Martin Luther King Dr, Cincinnati, OH, 45220, USA
| | - N Roxanna Razavi
- SUNY-ESF Department of Environmental Biology, 1 Forestry Derive, Syracuse, NY, 13210, USA
| | - Wayne Richter
- New York State Department of Environmental Conservation, Division of Fish and Wildlife, 625 Broadway, Albany, NY, 12233-4756, USA
| | - Amy K Sauer
- Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA
| | - Nina Schoch
- Adirondack Center for Loon Conservation, PO Box 195, Ray Brook, NY, 12977, USA
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5
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Pitoňáková T. Mercury concentration in the tissues of the Eurasian otter: a seasonal dependance in Slovakia. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:3795-3803. [PMID: 35962166 DOI: 10.1007/s11356-022-22459-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
The river otter is considered to be an important bioindicator of water clarity. This study focuses on mercury contamination within this species. Throughout the study, individuals from habitats in the foothills and surroundings of the Liptovská Mara reservoir were analyzed. Twenty-three samples of liver tissue, and twenty-two samples of hair and kidney tissue were collected. Of these samples, the average mercury concentration detected in tissues was 10.6 mg/kg in guard hairs; 12.9 mg/kg in under hairs; 3.3 mg/kg in kidney tissue; and 4.3 mg/kg in liver tissue. Analysis of certified reference material (ERM-BB186-Pig Kidney) was used to assist in the development of an accurate method for total mercury determination in animal tissues, to check the quality of measurements, and to validate the measurement method. Our method represented a high average percentage of recovery (> 95%) in the standard reference material matrix and a relative standard deviation (RSD) of 5% or less. Seasonality was determined to be a significant factor influencing the level of contamination of a given individual, both through mercury methylation within the aquatic environment and through fish ingestion by this apex semi-aquatic predator (guard hairs (p = 0.01); underfur (p = 0.04); kidney (p = 0.03); liver (p = 0.03)). Sex, location, and body size were not found to have a significant influence on heavy metal concentrations in river otters sampled in terms of season.
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Affiliation(s)
- Tatiana Pitoňáková
- Institute of High Mountain Biology, University of Žilina, Tatranská Javorina 7, 059 56, Tatranská Javorina, Slovakia.
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6
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Kalisinska E, Lanocha-Arendarczyk N, Podlasinska J. Current and historical nephric and hepatic mercury concentrations in terrestrial mammals in Poland and other European countries. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 775:145808. [PMID: 33621879 DOI: 10.1016/j.scitotenv.2021.145808] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/06/2021] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
The long-term anthropogenic release of mercury (Hg) into the environment has led to contamination of the biosphere, with all forms of Hg showing toxic effects and the ability to accumulate in organisms. Since the 1970s, efforts have been made in Western Europe to reduce Hg emissions and for the economic use of Hg, leading to a reduction in Hg exposure to humans and entire ecosystems. The purpose of this research was to present the total mercury (THg) burden in three mustelids (the piscivorous Eurasian otter and American mink, and the invertebrativorous European badger) inhabiting north-western Poland (mostly floodplains) and other European countries (literature data). Moreover, we wanted to investigate whether reductions in the environmental Hg burden in Europe have resulted in reductions in liver and kidney levels in wild terrestrial mammals (Eurasian otter, wild boar, red deer, roe deer, cervids, leporids, rodents, and ecotrophic groups: piscivorous mustelids, non-mustelids whose diets include aquatic prey, canids and other carnivores, omnivores, herbivores), between samples collected before and after 2000. We revealed significantly higher nephric THg levels in roadkilled than in trapped American minks. As roadkilled piscivorous mustelids from the same floodplain had similar hepatic and nephric THg concentrations, we suggest that the European research on Hg ecotoxicology should more often use alien American mink instead of the protected Eurasian otter. Badgers inhabiting Polish and other European floodplains bioaccumulated higher amounts of THg than those from other areas, and as such, may be recommended as bioindicator of mercury soil contamination. Our analysis of abundant data on mammalian hepatic and nephric THg concentrations (excluding non-piscivores mustelids) showed that in 12 of 21 cases, Hg concentrations had dropped significantly since 2000. This data signals a reduction in Hg contamination in terrestrial mammals, such as the Eurasian otter, and may be reason for cautious optimism.
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Affiliation(s)
- Elżbieta Kalisinska
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland.
| | - Natalia Lanocha-Arendarczyk
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland
| | - Joanna Podlasinska
- Department of Environmental Management, West Pomeranian University of Technology, Szczecin, Poland
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7
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Eccles KM, Thomas PJ, Chan HM. Spatial patterns of the exposure-response relationship between mercury and cortisol in the fur of river otter (Lontra canadensis). CHEMOSPHERE 2021; 263:127992. [PMID: 32835981 DOI: 10.1016/j.chemosphere.2020.127992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Fur has been validated as a useful biomarker medium for chemical exposures and biological responses in wildlife. Mercury (Hg) is known to act as an endocrine disruptor by altering brain neurochemistry. In this study, we investigated the spatial patterns of relationships between total Hg (THg) and cortisol in the fur of river otter (Lontra canadensis). Geotagged fur samples were obtained from a wildlife biomonitoring program (n = 72) and the North American Fur Auction (n = 37) between 2014 and 2017. Fur THg was measured using direct thermal decomposition and fur cortisol was measured using an enzyme-linked immunosorbent assay (ELISA). The average fur THg concentration was 11.50 ± 12.40 μg/g fur weight (f.w.), and the fur cortisol concentration was 5.71 ± 8.24 pg/mg. Results from the global ordinary least squares regression show no relationship between THg and fur cortisol concentrations. However, both Hg and cortisol were heterogeneously distributed across the landscape. When a localized geographically weighted regression (GWR) was used, a geographically distinct bi-phasic relationship was observed. We suggest this bi-phasic relationship is associated with a threshold THg concentration, beyond which, there was a negative association with measured fur cortisol. Results of a break-point analysis, with one break, indicate that the threshold is 16 ± 1.27 μg/g f. w of THg in fur. This research highlights the need to use appropriate spatial methods when assessing exposure-response relationships in wildlife across large geographical areas. The identified threshold can be used for regulatory purposes.
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Affiliation(s)
- Kristin M Eccles
- Department of Biology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
| | - Philippe J Thomas
- Department of Biology, 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, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
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Peterson SH, Ackerman JT, Hartman CA, Casazza ML, Feldheim CL, Herzog MP. Mercury exposure in mammalian mesopredators inhabiting a brackish marsh. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 273:115808. [PMID: 33497946 DOI: 10.1016/j.envpol.2020.115808] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/18/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
Bioaccumulation of environmental contaminants in mammalian predators can serve as an indicator of ecosystem health. We examined mercury concentrations of raccoons (Procyon lotor; n = 37 individuals) and striped skunks (Mephitis mephitis; n = 87 individuals) in Suisun Marsh, California, a large brackish marsh that is characterized by contiguous tracts of tidal marsh and seasonally impounded wetlands. Mean (standard error; range) total mercury concentrations in adult hair grown from 2015 to 2018 were 28.50 μg/g dw (3.05 μg/g dw; range: 4.46-81.01 μg/g dw) in raccoons and 4.85 μg/g dw (0.54 μg/g dw; range: 1.53-27.02 μg/g dw) in striped skunks. We reviewed mammalian hair mercury concentrations in the literature and raccoon mercury concentrations in Suisun Marsh were among the highest observed for wild mammals. Although striped skunk hair mercury concentrations were 83% lower than raccoons, they were higher than proposed background levels for mercury in mesopredator hair (1-5 μg/g). Hair mercury concentrations in skunks and raccoons were not related to animal size, but mercury concentrations were higher in skunks in poorer body condition. Large inter-annual differences in hair mercury concentrations suggest that methylmercury exposure to mammalian predators varied among years. Mercury concentrations of raccoon hair grown in 2017 were 2.7 times greater than hair grown in 2015, 1.7 times greater than hair grown in 2016, and 1.6 times greater than hair grown in 2018. Annual mean raccoon and skunk hair mercury concentrations increased with wetland habitat area. Furthermore, during 2017, raccoon hair mercury concentrations increased with the proportion of raccoon home ranges that was wetted habitat, as quantified using global positioning system (GPS) collars. The elevated mercury concentrations we observed in raccoons and skunks suggest that other wildlife at similar or higher trophic positions may also be exposed to elevated methylmercury bioaccumulation in brackish marshes.
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Affiliation(s)
- Sarah H Peterson
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA.
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
| | - C Alex Hartman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
| | - Michael L Casazza
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
| | - Cliff L Feldheim
- California Department of Water Resources, 3500 Industrial Blvd #131, West Sacramento, CA 95691, USA
| | - Mark P Herzog
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
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Chételat J, Ackerman JT, Eagles-Smith CA, Hebert CE. Methylmercury exposure in wildlife: A review of the ecological and physiological processes affecting contaminant concentrations and their interpretation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 711:135117. [PMID: 31831233 DOI: 10.1016/j.scitotenv.2019.135117] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/15/2019] [Accepted: 10/21/2019] [Indexed: 05/12/2023]
Abstract
Exposure to methylmercury (MeHg) can result in detrimental health effects in wildlife. With advances in ecological indicators and analytical techniques for measurement of MeHg in a variety of tissues, numerous processes have been identified that can influence MeHg concentrations in wildlife. This review presents a synthesis of theoretical principals and applied information for measuring MeHg exposure and interpreting MeHg concentrations in wildlife. Mercury concentrations in wildlife are the net result of ecological processes influencing dietary exposure combined with physiological processes that regulate assimilation, transformation, and elimination. Therefore, consideration of both physiological and ecological processes should be integrated when formulating biomonitoring strategies. Ecological indicators, particularly stable isotopes of carbon, nitrogen, and sulfur, compound-specific stable isotopes, and fatty acids, can be effective tools to evaluate dietary MeHg exposure. Animal species differ in their physiological capacity for MeHg elimination, and animal tissues can be inert or physiologically active, act as sites of storage, transformation, or excretion of MeHg, and vary in the timing of MeHg exposure they represent. Biological influences such as age, sex, maternal transfer, and growth or fasting are also relevant for interpretation of tissue MeHg concentrations. Wildlife tissues that represent current or near-term bioaccumulation and in which MeHg is the predominant mercury species (such as blood and eggs) are most effective for biomonitoring ecosystems and understanding landscape drivers of MeHg exposure. Further research is suggested to critically evaluate the use of keratinized external tissues to measure MeHg bioaccumulation, particularly for less-well studied wildlife such as reptiles and terrestrial mammals. Suggested methods are provided to effectively use wildlife for quantifying patterns and drivers of MeHg bioaccumulation over time and space, as well as for assessing the potential risk and toxicological effects of MeHg on wildlife.
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Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Ottawa, ON K1A 0H3, Canada.
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, United States
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, Oregon, 97331, United States
| | - Craig E Hebert
- Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Ottawa, ON K1A 0H3, Canada
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10
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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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11
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Rodríguez-Estival J, Ortiz-Santaliestra ME, Mateo R. Assessment of ecotoxicological risks to river otters from ingestion of invasive red swamp crayfish in metal contaminated areas: Use of feces to estimate dietary exposure. ENVIRONMENTAL RESEARCH 2020; 181:108907. [PMID: 31740034 DOI: 10.1016/j.envres.2019.108907] [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: 09/25/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 06/10/2023]
Abstract
The invasive red swamp crayfish (Procambarus clarkii) has become a major food resource for Eurasian otters (Lutra lutra) in the Iberian Peninsula. Crayfish accumulate large amounts of metals, and hence otters could be at risk of exposure and intoxication through crayfish consumption. We conducted a food safety risk assessment for otters inhabiting two historical mining areas in central Spain affected by lead (Pb) and mercury (Hg) pollution. Estimated daily intakes (EDI) of Pb and Hg were non-invasively calculated from the proportion of crayfish remains and metal levels in otter feces. We considered that the abdominal muscle and the carcass of crayfish differ significantly in relative weight, total metal content and bioavailability of metals to reduce the uncertainty of risk characterization. Fecal concentrations of Hg and Pb in the polluted areas were 1.878 and 6.554 μg/g d. w., respectively (13-fold and 7-fold higher compared to a non-polluted area). EDI of Hg and Pb in the polluted areas were 66.02 and 78.26 μg/kg-day, respectively (14- and 8-fold higher than in the reference area). EDI from the Hg area were above minimum levels susceptible to cause neurotoxicity in mustelids, and 6.3% were above levels susceptible to cause histopathological lessions. In the Pb area, 16.7% of EDI were consistent with levels causing reproductive effects. Metal exposure through crayfish consumption might prevent or slow the recovey of otters in these polluted environments, thus this factor should be considered in management strategies aimed to protect otter populations.
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Affiliation(s)
- Jaime Rodríguez-Estival
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain.
| | - Manuel E Ortiz-Santaliestra
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain
| | - Rafael Mateo
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain
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12
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BIOACCUMULATION OF MERCURY IN A TERRESTRIAL CARNIVORE, AMERICAN MARTEN ( MARTES AMERICANA). J Wildl Dis 2019; 56:388-396. [PMID: 31880989 DOI: 10.7589/2019-05-138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Studies that assess mercury bioaccumulation in small carnivores in terrestrial habitats are limited. We quantified total mercury (THg) in American marten (Martes americana) that were harvested for fur in Michigan, US, during 2013 and 2014. We quantified THg (dry weight) in hair, kidney, and liver samples and further analyzed hair for potential demographic and ecological factors that influence THg bioaccumulation. We found THg concentrations to be the highest in hair (1.228±0.475 µg/g, n=40), followed by kidney (0.922±0.651 µg/g, n=29) and liver (0.344±0.219 µg/g, n=26). Total mercury distributed predictably and significantly between tissue types, and hair was moderately predictive at modeling THg in kidney (R2=0.50, P<0.001, n=29) and weakly predictive in liver (R2=0.35, P<0.001, n=26), suggesting that hair, which is easily obtained, could be a useful sample type for future biomonitoring programs. The concentrations of THg in hair were higher in adults relative to juveniles, and adult female martens had the highest levels of THg (1.980±0.188 µg/g), as compared to juveniles and adult males. Results of generalized linear modeling suggested that THg hair concentrations were positively associated with marten age and trophic position (stable isotope ratio, δ15N). An interaction between δ15N and the year marten carcasses were collected showed that δ15N alone could be highly predictive of THg in some years but not in others. Annual changes in diet could lead to differing rates of mercury bioaccumulation and alter the usefulness of δ15N to predict THg in marten tissues. Further research should explore the connections between changes in prey availability, types of prey consumed, and the influence on bioaccumulation rates of mercury in terrestrial system mesocarnivores.
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13
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Weiss-Penzias PS, Bank MS, Clifford DL, Torregrosa A, Zheng B, Lin W, Wilmers CC. Marine fog inputs appear to increase methylmercury bioaccumulation in a coastal terrestrial food web. Sci Rep 2019; 9:17611. [PMID: 31772229 PMCID: PMC6879473 DOI: 10.1038/s41598-019-54056-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 11/04/2019] [Indexed: 11/08/2022] Open
Abstract
Coastal marine atmospheric fog has recently been implicated as a potential source of ocean-derived monomethylmercury (MMHg) to coastal terrestrial ecosystems through the process of sea-to-land advection of foggy air masses followed by wet deposition. This study examined whether pumas (Puma concolor) in coastal central California, USA, and their associated food web, have elevated concentrations of MMHg, which could be indicative of their habitat being in a region that is regularly inundated with marine fog. We found that adult puma fur and fur-normalized whiskers in our marine fog-influenced study region had a mean (±SE) total Hg (THg) (a convenient surrogate for MMHg) concentration of 1544 ± 151 ng g-1 (N = 94), which was three times higher (P < 0.01) than mean THg in comparable samples from inland areas of California (492 ± 119 ng g-1, N = 18). Pumas in California eat primarily black-tailed and/or mule deer (Odocoileus hemionus), and THg in deer fur from the two regions was also significantly different (coastal 28.1 ± 2.9, N = 55, vs. inland 15.5 ± 1.5 ng g-1, N = 40). We suggest that atmospheric deposition of MMHg through fog may be contributing to this pattern, as we also observed significantly higher MMHg concentrations in lace lichen (Ramalina menziesii), a deer food and a bioindicator of atmospheric deposition, at sites with the highest fog frequencies. At these ocean-facing sites, deer samples had significantly higher THg concentrations compared to those from more inland bay-facing sites. Our results suggest that fog-borne MMHg, while likely a small fraction of Hg in all atmospheric deposition, may contribute, disproportionately, to the bioaccumulation of Hg to levels that approach toxicological thresholds in at least one apex predator. As global mercury levels increase, coastal food webs may be at risk to the toxicological effects of increased methylmercury burdens.
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Affiliation(s)
- Peter S Weiss-Penzias
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA.
| | - Michael S Bank
- Institute of Marine Research, Department of Contaminants and Biohazards, Bergen, Norway
- University of Massachusetts, Department of Environmental Conservation, Amherst, MA, USA
| | - Deana L Clifford
- Wildlife Investigations Lab, California Department of Fish and Wildlife, Rancho Cordova, CA, USA
- University of California, School of Veterinary Medicine, Department of Medicine and Epidemiology, Davis, CA, USA
| | - Alicia Torregrosa
- United States Geological Survey, Western Geographic Science Center, Menlo Park, CA, USA
| | - Belle Zheng
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - Wendy Lin
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
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14
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Distribution of organic and inorganic mercury across the pelts of Canadian river otter (Lontra canadensis). Sci Rep 2019; 9:3237. [PMID: 30824798 PMCID: PMC6397270 DOI: 10.1038/s41598-019-39893-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/21/2019] [Indexed: 11/08/2022] Open
Abstract
Fur is a common biomarker of environmental mercury (Hg) exposure. Further, there are well-established relationships between total mercury (THg) in fur and organs. However, these models assumed that THg is uniformly distributed across the fur in a pelt. In this study, we assess the distribution of THg and methylmercury (MeHg) across the pelts of four river otters (Lontra canadensis). THg concentrations were measured in the topcoat (n = 95) and undercoat fur (n = 95). MeHg was measured in a subset of these samples (n = 10). Patterns of THg and MeHg were explored using cluster analyses and ANOVAs. Significant differences existed between THg in topcoat and undercoat and between anatomical region (head/body/tail/legs) and fur regions (dorsal/ventral/furline). The cluster analysis showed significant THg clusters in undercoat fur and to a lesser extent topcoat fur. Further, the error rate for predicting internal THg is lowest in the forebody region of the topcoat, thus, making this the optimal region to sample for biomonitoring. Fur samples taken outside of this region could result in prediction error as high as 140% when estimating internal organ THg. The ratio of MeHg in THg in topcoat fur was measured at 95.7 ± 3.4% indicating THg concentrations can be used to assess MeHg exposure.
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15
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Ewald JD, Kirk JL, Li M, Sunderland EM. Organ-specific differences in mercury speciation and accumulation across ringed seal (Phoca hispida) life stages. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 650:2013-2020. [PMID: 30290344 DOI: 10.1016/j.scitotenv.2018.09.299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/17/2018] [Accepted: 09/22/2018] [Indexed: 05/12/2023]
Abstract
Methylmercury (MeHg) is a central nervous system toxicant and exposures can adversely affect the health of marine mammals. Mercuric selenide (HgSe) in marine mammal tissues is hypothesized to result from a protective detoxification mechanism, but toxicokinetic processes contributing to its formation are poorly understood. Here, new data is reported on speciated Hg concentrations in multiple organs of n = 56 ringed seals (Phoca hispida) from Labrador, Canada, and compare concentrations to previously published data from Greenland seals. A higher proportion of Hg is found to accumulate in the kidney of young-of-the-year (YOY) ringed seals compared to adults. A toxicokinetic model for Hg species is developed and evaluated to better understand factors affecting variability in Hg concentrations among organs and across life stages. Prior work postulated that HgSe formation only occurs in the liver of mature seals, but model results suggest HgSe formation occurs across all life stages. Higher proportions of HgSe in mature seal livers compared to YOY seals likely results from the slow accumulation and elimination of HgSe (total body half-life = 500 days) compared to other Hg species. HgSe formation in the liver reduces modeled blood concentrations of MeHg by only 6%. Thus, HgSe formation may not substantially reduce MeHg transport across the blood-brain barrier of ringed seals, leaving them susceptible to the neurotoxic effects of MeHg exposure.
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Affiliation(s)
- Jessica D Ewald
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States; Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada.
| | - Jane L Kirk
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, Ontario L7S 1A1, Canada
| | - Miling Li
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, United States
| | - Elsie M Sunderland
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, United States
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16
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Korstian JM, Chumchal MM, Bennett VJ, Hale AM. Mercury contamination in bats from the central United States. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:160-165. [PMID: 28792083 DOI: 10.1002/etc.3940] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/04/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
Mercury (Hg) is a highly toxic metal that has detrimental effects on wildlife. We surveyed Hg concentrations in 10 species of bats collected at wind farms in the central United States and found contamination in all species. Mercury concentration in fur was highly variable both within and between species (range: 1.08-10.52 µg/g). Despite the distance between sites (up to 1200 km), only 2 of the 5 species sampled at multiple locations had fur Hg concentrations that differed between sites. Mercury concentrations observed in the present study all fell within the previously reported ranges for bats collected from the northeastern United States and Canada, although many of the bats we sampled had lower maximum Hg concentrations. Juvenile bats had lower concentrations of Hg in fur compared with adult bats, and we found no significant effect of sex on Hg concentrations in fur. For a subset of 2 species, we also measured Hg concentration in muscle tissue; concentrations were much higher in fur than in muscle, and Hg concentrations in the 2 tissue types were weakly correlated. Abundant wind farms and ongoing postconstruction fatality surveys offer an underutilized opportunity to obtain tissue samples that can be used to assess Hg contamination in bats. Environ Toxicol Chem 2018;37:160-165. © 2018 SETAC.
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Affiliation(s)
| | | | - Victoria J Bennett
- School of Geology, Energy and the Environment, Texas Christian University, Fort Worth, Texas, USA
| | - Amanda M Hale
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
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