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Janssen SE, Kotalik CJ, Willacker JJ, Tate MT, Pritz CMF, Nelson SJ, Krabbenhoft DP, Walters DM, Eagles-Smith CA. Geographic Drivers of Mercury Entry into Aquatic Food Webs Revealed by Mercury Stable Isotopes in Dragonfly Larvae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39012137 DOI: 10.1021/acs.est.4c02436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Atmospheric mercury (Hg) emissions and subsequent transport and deposition are major concerns within protected lands, including national parks, where Hg can bioaccumulate to levels detrimental to human and wildlife health. Despite this risk to biological resources, there is limited understanding of the relative importance of different Hg sources and delivery pathways within the protected regions. Here, we used Hg stable isotope measurements within a single aquatic bioindicator, dragonfly larvae, to determine if these tracers can resolve spatial patterns in Hg sources, delivery mechanisms, and aquatic cycling at a national scale. Mercury isotope values in dragonfly tissues varied among habitat types (e.g., lentic, lotic, and wetland) and geographic location. Photochemical-derived isotope fractionation was habitat-dependent and influenced by factors that impact light penetration directly or indirectly, including dissolved organic matter, canopy cover, and total phosphorus. Strong patterns for Δ200Hg emerged in the western United States, highlighting the relative importance of wet deposition sources in arid regions in contrast to dry deposition delivery in forested regions. This work demonstrates the efficacy of dragonfly larvae as biosentinels for Hg isotope studies due to their ubiquity across freshwater ecosystems and ability to track variation in Hg sources and processing attributed to small-scale habitat and large-scale regional patterns.
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Affiliation(s)
- Sarah E Janssen
- US Geological Survey Upper Midwest Water Science Center, One Gifford Pinchot Drive,, Madison, Wisconsin 53726, United States
| | - Christopher J Kotalik
- US Geological Survey Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, Missouri 65201, United States
| | - James J Willacker
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200SW Jefferson Way, Corvallis, Oregon 97331, United States
| | - Michael T Tate
- US Geological Survey Upper Midwest Water Science Center, One Gifford Pinchot Drive,, Madison, Wisconsin 53726, United States
| | - Colleen M Flanagan Pritz
- National Park Service, Air Resources Division, P.O. Box 25287, Denver, Colorado 80225, United States
| | - Sarah J Nelson
- Appalachian Mountain Club, 361 Route 16, Gorham, New Hampshire 03581, United States
| | - David P Krabbenhoft
- US Geological Survey Upper Midwest Water Science Center, One Gifford Pinchot Drive,, Madison, Wisconsin 53726, United States
| | - David M Walters
- US Geological Survey Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, Missouri 65201, United States
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200SW Jefferson Way, Corvallis, Oregon 97331, United States
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2
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Tornabene BJ, Hossack BR, Halstead BJ, Eagles-Smith CA, Adams MJ, Backlin AR, Brand AB, Emery CS, Fisher RN, Fleming J, Glorioso BM, Grear DA, Grant EHC, Kleeman PM, Miller DAW, Muths E, Pearl CA, Rowe JC, Rumrill CT, Waddle JH, Winzeler ME, Smalling KL. Broad-Scale Assessment of Methylmercury in Adult Amphibians. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:17511-17521. [PMID: 37902062 PMCID: PMC10653216 DOI: 10.1021/acs.est.3c05549] [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] [Received: 07/14/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/31/2023]
Abstract
Mercury (Hg) is a toxic contaminant that has been mobilized and distributed worldwide and is a threat to many wildlife species. Amphibians are facing unprecedented global declines due to many threats including contaminants. While the biphasic life history of many amphibians creates a potential nexus for methylmercury (MeHg) exposure in aquatic habitats and subsequent health effects, the broad-scale distribution of MeHg exposure in amphibians remains unknown. We used nonlethal sampling to assess MeHg bioaccumulation in 3,241 juvenile and adult amphibians during 2017-2021. We sampled 26 populations (14 species) across 11 states in the United States, including several imperiled species that could not have been sampled by traditional lethal methods. We examined whether life history traits of species and whether the concentration of total mercury in sediment or dragonflies could be used as indicators of MeHg bioaccumulation in amphibians. Methylmercury contamination was widespread, with a 33-fold difference in concentrations across sites. Variation among years and clustered subsites was less than variation across sites. Life history characteristics such as size, sex, and whether the amphibian was a frog, toad, newt, or other salamander were the factors most strongly associated with bioaccumulation. Total Hg in dragonflies was a reliable indicator of bioaccumulation of MeHg in amphibians (R2 ≥ 0.67), whereas total Hg in sediment was not (R2 ≤ 0.04). Our study, the largest broad-scale assessment of MeHg bioaccumulation in amphibians, highlights methodological advances that allow for nonlethal sampling of rare species and reveals immense variation among species, life histories, and sites. Our findings can help identify sensitive populations and provide environmentally relevant concentrations for future studies to better quantify the potential threats of MeHg to amphibians.
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Affiliation(s)
- Brian J. Tornabene
- U.S.
Geological Survey, Northern Rocky Mountain
Science Center, Missoula, Montana 59801, United States
| | - Blake R. Hossack
- U.S.
Geological Survey, Northern Rocky Mountain
Science Center, Missoula, Montana 59801, United States
- Wildlife
Biology Program, W. A. Franke College of Forestry & Conservation, University of Montana, Missoula, Montana 59812, United States
| | - Brian J. Halstead
- U.S.
Geological Survey, Western Ecological Research
Center, Dixon, California 95620, United States
| | - Collin A. Eagles-Smith
- U.S.
Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97331 United States
| | - Michael J. Adams
- U.S.
Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97331 United States
| | - Adam R. Backlin
- U.S.
Geological Survey, Western Ecological Research
Center, San Diego, California 92101, United States
| | - Adrianne B. Brand
- U.S. Geological
Survey, Eastern Ecological Science Center
(Patuxent Wildlife Research Center), Turners Falls, Massachusetts 01376, United States
| | - Colleen S. Emery
- U.S.
Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97331 United States
| | - Robert N. Fisher
- U.S.
Geological Survey, Western Ecological Research
Center, San Diego, California 92101, United States
| | - Jill Fleming
- U.S. Geological
Survey, Eastern Ecological Science Center
(Patuxent Wildlife Research Center), Turners Falls, Massachusetts 01376, United States
| | - Brad M. Glorioso
- U.S.
Geological
Survey, Wetland and Aquatic Research Center, Lafayette, Louisiana 70506, United States
| | - Daniel A. Grear
- U.S.
Geological
Survey, National Wildlife Health Center, Madison, Wisconsin 53711, United States
| | - Evan H. Campbell Grant
- U.S. Geological
Survey, Eastern Ecological Science Center
(Patuxent Wildlife Research Center), Turners Falls, Massachusetts 01376, United States
| | - Patrick M. Kleeman
- U.S.
Geological
Survey, Western Ecological Research Center, Point Reyes Station, California 94956, United States
| | - David A. W. Miller
- Department
of Ecosystem Science and Management, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Erin Muths
- U.S. Geological
Survey, Fort Collins Science Center, Fort Collins, Colorado 80526, United States
| | - Christopher A. Pearl
- U.S.
Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97331 United States
| | - Jennifer C. Rowe
- U.S.
Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97331 United States
| | - Caitlin T. Rumrill
- U.S.
Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97331 United States
| | - J. Hardin Waddle
- U.S. Geological
Survey, Wetland and Aquatic Research Center, Gainesville, Florida 32653, United States
| | - Megan E. Winzeler
- U.S.
Geological
Survey, National Wildlife Health Center, Madison, Wisconsin 53711, United States
| | - Kelly L. Smalling
- U.S. Geological
Survey, New Jersey Water Science Center, Lawrenceville, New Jersey 08648, United States
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3
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Riva-Murray K, Bradley PM, Brigham ME. Methylmercury-total mercury ratios in predator and primary consumer insects from Adirondack streams (New York, USA). ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1644-1658. [PMID: 32180092 DOI: 10.1007/s10646-020-02191-7] [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] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
Mercury (Hg) is a global pollutant that affects biota in remote settings due to atmospheric deposition of inorganic Hg, and its conversion to methylmercury (MeHg), the bioaccumulating and toxic form. Characterizing biotic MeHg is important for evaluating aquatic ecosystem responses to changes in Hg inputs. Aquatic insects possess many qualities desired for MeHg biomonitoring, but are not widely used, largely because of limited information regarding percentages of total mercury (THg) composed of MeHg (i.e., MeHg%) in various taxa. Here, we examine taxonomic, spatial, and seasonal variation in MeHg% of stream-dwelling predator and primary-consumer insects from nine streams in the Adirondack region (NY, USA). Predator MeHg% was high (median 94%) and did not differ significantly among five taxa. MeHg% in selected dragonflies (the most abundant predators, Odonata: Aeshnidae and Libellulidae) exhibited little seasonal and spatial variation, and THg concentration was strongly correlated with aqueous (filtered) MeHg (FMeHg; rs = 0.76). In contrast, MeHg% in primary consumers-shredders (northern caddisflies [Trichoptera: Limnephilidae]) and scrapers (flathead mayflies [Ephemeroptera: Heptageniidae]), were lower (medians 52% and 35%, respectively), and differed significantly between taxa, among sites, and seasonally. Correlations of THg with FMeHg were weak (shredders, rs = 0.45, p = 0.09) or not significant (scrapers, p = 0.89). The higher MeHg% of predators corresponded with their higher trophic positions (indicated by nitrogen stable isotopes). Results suggest obligate predators hold the most promise for the use of THg as a surrogate for MeHg biomonitoring with aquatic insects within the Adirondack region.
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Affiliation(s)
| | - Paul M Bradley
- U.S. Geological Survey, 720 Gracern Road, Columbia, SC, 29210, USA
| | - Mark E Brigham
- U.S. Geological Survey, 2280 Woodale Drive, Mounds View, MN, 55112, USA
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Nelson SJ, Chen CY, Kahl JS. Dragonfly larvae as biosentinels of Hg bioaccumulation in Northeastern and Adirondack lakes: relationships to abiotic factors. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1659-1672. [PMID: 31883061 PMCID: PMC8418898 DOI: 10.1007/s10646-019-02149-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/05/2019] [Indexed: 05/28/2023]
Abstract
Mercury (Hg) is a toxic pollutant, widespread in northeastern US ecosystems. Resource managers' efforts to develop fish consumption advisories for humans and to focus conservation efforts for fish-eating wildlife are hampered by spatial variability. Dragonfly larvae can serve as biosentinels for Hg given that they are widespread in freshwaters, long-lived, exhibit site fidelity, and bioaccumulate relatively high mercury concentrations, mostly as methylmercury (88% ± 11% MeHg in this study). We sampled lake water and dragonfly larvae in 74 northeastern US lakes that are part of the US EPA Long-Term Monitoring Network, including 45 lakes in New York, 43 of which are in the Adirondacks. Aqueous dissolved organic carbon (DOC) and total Hg (THg) were strongly related to MeHg in lake water. Dragonfly larvae total mercury ranged from 0.016-0.918 μg/g, dw across the study area; Adirondack lakes had the minimum and maximum concentrations. Aqueous MeHg and dragonfly THg were similar between the Adirondack and Northeast regions, but a majority of lakes within the highest quartile of dragonfly THg were in the Adirondacks. Using landscape, lake chemistry, and lake morphometry data, we evaluated relationships with MeHg in lake water and THg in dragonfly larvae. Lakewater DOC and lake volume were strong predictors for MeHg in water. Dragonfly THg Bioaccumulation Factors (BAFs, calculated as [dragonfly THg]:[aqueous MeHg]) increased as lake volume increased, suggesting that lake size influences Hg bioaccumulation or biomagnification. BAFs declined with increasing DOC, supporting a potential limiting effect for MeHg bioavailability with higher DOC.
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Affiliation(s)
- Sarah J Nelson
- School of Forest Resources, University of Maine, 5755 Nutting Hall, Orono, ME, 04469-5755, USA.
- Appalachian Mountain Club, PO Box 298, Route 16, Gorham, NH, 03581, USA.
| | - Celia Y Chen
- Department of Biological Sciences, Dartmouth College, HB 6044, Class of '78 Life Sciences Center, Hanover, NH, 03755, USA
| | - Jeffrey S Kahl
- Thomas College, School of Arts and Sciences, 180 West River Road, Waterville, ME, 04901, USA
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Eagles-Smith CA, Willacker JJ, Nelson SJ, Flanagan Pritz CM, Krabbenhoft DP, Chen CY, Ackerman JT, Grant EHC, Pilliod DS. A National-Scale Assessment of Mercury Bioaccumulation in United States National Parks Using Dragonfly Larvae As Biosentinels through a Citizen-Science Framework. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8779-8790. [PMID: 32633494 PMCID: PMC7790342 DOI: 10.1021/acs.est.0c01255] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 06/01/2023]
Abstract
We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems, using dragonfly larvae as biosentinels, by developing a citizen-science network to facilitate biological sampling. Implementing a carefully designed sampling methodology for citizen scientists, we developed an effective framework for a landscape-level inquiry that might otherwise be resource limited. We assessed the variation in dragonfly Hg concentrations across >450 sites spanning 100 United States National Park Service units and examined intrinsic and extrinsic factors associated with the variation in Hg concentrations. Mercury concentrations ranged between 10.4 and 1411 ng/g dry weight across sites and varied among habitat types. Dragonfly total Hg (THg) concentrations were up to 1.8-fold higher in lotic habitats than in lentic habitats and 37% higher in waterbodies with abundant wetlands along their margins than those without wetlands. Mercury concentrations in dragonflies differed among families but were correlated (r2 > 0.80) with each other, enabling adjustment to a consistent family to facilitate spatial comparisons among sampling units. Dragonfly THg concentrations were positively correlated with THg concentrations in both fish and amphibians from the same locations, indicating that dragonfly larvae are effective indicators of Hg bioavailability in aquatic food webs. We used these relationships to develop an integrated impairment index of Hg risk to aquatic ecosytems and found that 12% of site-years exceeded high or severe benchmarks of fish, wildlife, or human health risk. Collectively, this continental-scale study demonstrates the utility of dragonfly larvae for estimating the potential mercury risk to fish and wildlife in aquatic ecosystems and provides a framework for engaging citizen science as a component of landscape Hg monitoring programs.
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Affiliation(s)
- Collin A. Eagles-Smith
- United
States Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97330, United States
| | - James J. Willacker
- United
States Geological Survey, Forest and Rangeland
Ecosystem Science Center, Corvallis, Oregon 97330, United States
| | - Sarah J. Nelson
- School
of Forest Resources, University of Maine, Orono, Maine 04469, United States
- Appalachian
Mountain Club, Gorham, New Hampshire 03581, United States
| | - Colleen M. Flanagan Pritz
- National
Park Service, Air Resources Division,
National Resource, Stewardship and Science Directorate, Lakewood, Colorado 80228, United States
| | - David P. Krabbenhoft
- United
States Geological Survey, Upper Midwest Water
Science Center, Middleton, Wisconsin 53562, United States
| | - Celia Y. Chen
- Department
of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Joshua T. Ackerman
- United
States Geological Survey, Western Ecological
Research Center, Dixon, California 95620, United States
| | - Evan H. Campbell Grant
- United
States Geological Survey, Patuxent Wildlife
Research Center, Turners Falls, Massachussetts 01376, United States
| | - David S. Pilliod
- United
States Geological Survey, Forest and Rangeland
Ecosystem Science Center, Boise, Idaho 83706, United States
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6
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Environmental-friendly Contamination Assessment of Habitats Based on the Trace Element Content of Dragonfly Exuviae. WATER 2019. [DOI: 10.3390/w11112200] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We tested the usefulness of exuviae as an environmentally friendly method for exploring the variability of the trace element contents of protected insect populations without killing specimens. It is a notable characteristic of dragonflies that they are good ecological indicators for both aquatic and terrestrial habitat quality. Thus, we investigated the trace element accumulation in different stages of dragonflies: larva, exuvia, and adult. Using microwave plasma atomic emission spectrometry (MP-AES), we analysed the concentrations of Al, Ba, Cr, Cu, Fe, Mn, Pb, Sr and Zn. We found that the trace element contents of exuviae are a good proxy of the trace element contents of both the larvae and the adults. We conclude that exuvia is useful for assessing the environmental health of aquatic ecosystems. It is an environmentally friendly method and it can be used even in the case of protected dragonfly species.
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7
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Jacobus LM, Macadam CR, Sartori M. Mayflies (Ephemeroptera) and Their Contributions to Ecosystem Services. INSECTS 2019; 10:E170. [PMID: 31207933 PMCID: PMC6628430 DOI: 10.3390/insects10060170] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/03/2019] [Accepted: 06/06/2019] [Indexed: 11/16/2022]
Abstract
This work is intended as a general and concise overview of Ephemeroptera biology, diversity, and services provided to humans and other parts of our global array of freshwater and terrestrial ecosystems. The Ephemeroptera, or mayflies, are a small but diverse order of amphinotic insects associated with liquid freshwater worldwide. They are nearly cosmopolitan, except for Antarctica and some very remote islands. The existence of the subimago stage is unique among extant insects. Though the winged stages do not have functional mouthparts or digestive systems, the larval, or nymphal, stages have a variety of feeding approaches-including, but not limited to, collector-gatherers, filterers, scrapers, and active predators-with each supported by a diversity of morphological and behavioral adaptations. Mayflies provide direct and indirect services to humans and other parts of both freshwater and terrestrial ecosystems. In terms of cultural services, they have provided inspiration to musicians, poets, and other writers, as well as being the namesakes of various water- and aircraft. They are commemorated by festivals worldwide. Mayflies are especially important to fishing. Mayflies contribute to the provisioning services of ecosystems in that they are utilized as food by human cultures worldwide (having one of the highest protein contents of any edible insect), as laboratory organisms, and as a potential source of antitumor molecules. They provide regulatory services through their cleaning of freshwater. They provide many essential supporting services for ecosystems such as bioturbation, bioirrigation, decomposition, nutrition for many kinds of non-human animals, nutrient cycling and spiraling in freshwaters, nutrient cycling between aquatic and terrestrial systems, habitat for other organisms, and serving as indicators of ecosystem health. About 20% of mayfly species worldwide might have a threatened conservation status due to influences from pollution, invasive alien species, habitat loss and degradation, and climate change. Even mitigation of negative influences has benefits and tradeoffs, as, in several cases, sustainable energy production negatively impacts mayflies.
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Affiliation(s)
- Luke M Jacobus
- Division of Science, Indiana University Purdue University Columbus, 4601 Central Ave., Columbus, IN 47203, USA.
| | - Craig R Macadam
- Buglife-The Invertebrate Conservation Trust, Balallan House, 24 Allan Park, Stirling, Scotland FK8 2QG, UK.
| | - Michel Sartori
- Musée cantonal de zoologie, Palais de Rumine, Place de la Riponne 6, CH-1005 Lausanne, Switzerland.
- Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland.
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8
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Tsz-Ki Tsui M, Liu S, Brasso RL, Blum JD, Kwon SY, Ulus Y, Nollet YH, Balogh SJ, Eggert SL, Finlay JC. Controls of Methylmercury Bioaccumulation in Forest Floor Food Webs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2434-2440. [PMID: 30727732 DOI: 10.1021/acs.est.8b06053] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Compared to the extensive research on aquatic ecosystems, very little is known about the sources and trophic transfer of methylmercury (MeHg) in terrestrial ecosystems. In this study, we examine energy flow and trophic structure using stable carbon (δ13C) and nitrogen (δ15N) isotope ratios, respectively, and MeHg levels in basal resources and terrestrial invertebrates from four temperate forest ecosystems. We show that MeHg levels in biota increased significantly ( p < 0.01) with δ13C and δ15N at all sites, implying the importance of both microbially processed diets (with increased δ13C) and trophic level (with increased δ15N) at which organisms feed, on MeHg levels in forest floor biota. The trophic magnification slopes of MeHg (defined as the slope of log10MeHg vs δ15N) for these forest floor food webs (0.20-0.28) were not significantly different ( p > 0.05) from those observed for diverse temperate freshwater systems (0.24 ± 0.07; n = 78), demonstrating for the first time the nearly equivalent efficiencies with which MeHg moves up the food chain in these contrasting ecosystem types. Our results suggest that in situ production of MeHg within the forest floor and efficient biomagnification both elevate MeHg levels in carnivorous invertebrates in temperate forests, which can contribute to significant bioaccumulation of this neurotoxin in terrestrial apex predators.
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Affiliation(s)
- Martin Tsz-Ki Tsui
- Department of Biology , University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Songnian Liu
- Department of Biology , University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Rebecka L Brasso
- Department of Zoology , Weber State University , Ogden , Utah 84408 , United States
| | - Joel D Blum
- Department of Earth and Environmental Sciences , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Sae Yun Kwon
- Division of Environmental Science and Engineering , Pohang University of Science and Technology , Pohang 37673 , South Korea
| | - Yener Ulus
- Department of Biology , University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Yabing H Nollet
- Metropolitan Council Environmental Services , St. Paul , Minnesota 55106 , United States
| | - Steven J Balogh
- Metropolitan Council Environmental Services , St. Paul , Minnesota 55106 , United States
| | - Sue L Eggert
- U.S.D.A. Forest Service , Northern Research Station, Grand Rapids , Minnesota 55744 , United States
| | - Jacques C Finlay
- Department of Ecology, Evolution, and Behavior , University of Minnesota , St. Paul , Minnesota 55108 , United States
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9
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Wolfe JD, Lane OP, Brigham RM, Hall BD. Mercury exposure to red-winged blackbirds (Agelaius phoeniceus) and dragonfly (Odonata: Aeshnidae) nymphs in Prairie Pothole wetlands. Facets (Ott) 2018. [DOI: 10.1139/facets-2017-0086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Prairie Pothole Region (PPR) in the northern Great Plains is an area of ecological significance, serving as an important breeding site for avian wildlife. However, organisms feeding within the PPR may be at risk of mercury (Hg) exposure due to deposition of anthropogenic emissions and the high Hg methylation potential of PPR wetlands. We quantified Hg concentrations in red-winged blackbirds’ ( Agelaius phoeniceus (Linnaeus, 1766); RWBLs) blood, feathers, and eggs in the spring and summer breeding season and compared our values with those from RWBLs sampled from ecoregions across North America. Hg concentrations in whole water, aeshnid dragonfly nymphs, and RWBL tissues varied by wetland and were below those considered to elicit acute effects in wildlife, and egg total Hg (THg) concentrations were significantly related to spring whole water methylmercury concentrations. Only RWBL blood THg concentrations showed a clear increase in summer compared with spring, resulting in decoupling of summer blood and feather THg concentrations. Moreover, blood THg concentrations varied by ecoregion, with those impacted by an industrial point source exhibiting high Hg levels. Our study emphasizes that tissue renewal time as well as ecological factors such as competition and diet shifts are important considerations when using RWBLs to assess biological Hg exposure.
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Affiliation(s)
- Jared D. Wolfe
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - Oksana P. Lane
- Biodiversity Research Institute, 276 Canco Road, Portland, ME 04103, USA
| | - R. Mark Brigham
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - Britt D. Hall
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
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10
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Lisón F, Espín S, Aroca B, Calvo JF, García-Fernández AJ. Assessment of mercury exposure and maternal-foetal transfer in Miniopterus schreibersii (Chiroptera: Miniopteridae) from southeastern Iberian Peninsula. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:5497-5508. [PMID: 28028704 DOI: 10.1007/s11356-016-8271-z] [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: 03/08/2016] [Accepted: 12/13/2016] [Indexed: 06/06/2023]
Abstract
Mercury (Hg) is a highly toxic and widely distributed metal that is bioaccumulated in insectivorous mammals and may cause adverse effects on the reproductive system. Bats are considered excellent Hg bioindicators due to their wide distribution, life span, trophic position, metabolic rate and food intake. However, few studies have analysed Hg residues in bats, and to the best of our knowledge, no studies have been made in the Iberian Peninsula. The main aim of this study was to undertake the first ever assessment of Hg exposure in Schreiber's bent-winged bats inhabiting a natural cave in the southeast of Spain. The findings suggest that Schreiber's bent-winged bats in the sampling area are chronically exposed to low levels of Hg. The Hg concentrations found in different tissues (fur, kidney, liver, muscle and brain) were below the threshold levels associated with toxic effects in mammals. Non-gestating females showed Hg concentrations in the brain and muscle that doubled those found in gestating females. This could be due to Hg mobilization from the mother to the foetus in gestating females, although other factors could contribute to explain this result such as variations in hunting areas and the insect-prey consumed and/or different energetic needs and average food consumption during the breeding season. Hg levels were 1.7 times higher, although not significant, in foetus' brains than in the maternal brains, and Hg concentration in foetus' brain was significantly correlated with levels in the corresponding mothers' kidney. These results suggest that there could be an active mother-to-foetus transfer of Hg in bats, which would be of special relevance in a scenario of higher Hg exposure than that found in this study. However, further research is needed to support this view due to the limited number of samples analysed. Given the scarce ecotoxicological data available for bats and their protected status, we encourage further opportunistic studies using carcasses found in the field, the validation of non-destructive samples such as fur and guano for Hg monitoring, and new modelling approaches that will increase the data needed for proper ecological risk assessment in bat populations.
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Affiliation(s)
- Fulgencio Lisón
- Department of Ecology and Hydrology, Faculty of Biology, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain
- Laboratorio de Ecología del Paisaje Forestal, Departamento de Ciencias Forestales, Universidad de La Frontera, P.O. Box-54-D, Temuco, Chile
| | - Silvia Espín
- Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.
- Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland.
| | - Bárbara Aroca
- Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain
| | - José F Calvo
- Department of Ecology and Hydrology, Faculty of Biology, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain
| | - Antonio J García-Fernández
- Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain
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11
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Jeremiason JD, Reiser TK, Weitz RA, Berndt ME, Aiken GR. Aeshnid dragonfly larvae as bioindicators of methylmercury contamination in aquatic systems impacted by elevated sulfate loading. ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:456-468. [PMID: 26738880 DOI: 10.1007/s10646-015-1603-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/22/2015] [Indexed: 06/05/2023]
Abstract
Methylmercury (MeHg) levels in dragonfly larvae and water were measured over two years in aquatic systems impacted to varying degrees by sulfate releases related to iron mining activity. This study examined the impact of elevated sulfate loads on MeHg concentrations and tested the use of MeHg in dragonfly larvae as an indicator of MeHg levels in a range of aquatic systems including 16 river/stream sites and two lakes. MeHg concentrations in aeshnid dragonfly larvae were positively correlated (R(2) = 0.46, p < 0.01) to peak MeHg concentrations in the dissolved phase for the combined years of 2012 and 2013. This relation was strong in 2012 (R(2) = 0.85, p < 0.01), but showed no correlation in 2013 (R(2) = 0.02, p > 0.05). MeHg in dragonfly larvae were not elevated at the highest sulfate sites, but rather the reverse was generally observed. Record rainfall events in 2012 and above average rainfall in 2013 likely delivered the majority of Hg and MeHg to these systems via interflow and activated groundwater flow through reduced sediments. As a result, the impacts of elevated sulfate releases due to mining activities were not apparent in these systems where little of the sulfate is reduced. Lower bioaccumulation factors for MeHg in aeshnid dragonfly larvae were observed with increasing dissolved organic carbon (DOC) concentrations. This finding is consistent with previous studies showing that MeHg in high DOC systems is less bioavailable; an equilibrium model shows that more MeHg being associated with DOC rather than algae at the base of the food chain readily explains the lower bioaccumulation factors.
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Affiliation(s)
| | - T K Reiser
- Gustavus Adolphus College, St Peter, MN, 56082, USA
| | - R A Weitz
- Gustavus Adolphus College, St Peter, MN, 56082, USA
| | - M E Berndt
- Minnesota Department of Natural Resources, St Paul, MN, USA
| | - G R Aiken
- US Geological Survey, 3215 Marine St., Boulder, CO, 80309, USA
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