1
|
Eckley CS, Luxton TP, Knightes CD, Shah V. Methylmercury Production and Degradation under Light and Dark Conditions in the Water Column of the Hells Canyon Reservoirs, USA. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:1829-1839. [PMID: 33729607 PMCID: PMC8745031 DOI: 10.1002/etc.5041] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/28/2021] [Accepted: 03/09/2021] [Indexed: 05/28/2023]
Abstract
Methylmercury (MeHg) is a highly toxic form of mercury that can bioaccumulate in fish tissue. Methylmercury is produced by anaerobic bacteria, many of which are also capable of MeHg degradation. In addition, demethylation in surface waters can occur via abiotic sunlight-mediated processes. The goal of the present study was to understand the relative importance of microbial Hg methylation/demethylation and abiotic photodemethylation that govern the mass of MeHg within an aquatic system. The study location was the Hells Canyon complex of 3 reservoirs on the Idaho-Oregon border, USA, that has fish consumption advisories as a result of elevated MeHg concentrations. Our study utilized stable isotope addition experiments to trace MeHg formation and degradation within the water column of the reservoirs to understand the relative importance of these processes on the mass of MeHg using the Water Quality Analysis Simulation Program. The results showed that rates of MeHg production and degradation within the water column were relatively low (<0.07 d-1 ) but sufficient to account for most of the MeHg observed with the system. Most MeHg production within the water column appeared to occur in the spring when much of the water column was in the processes of becoming anoxic. In the surface waters, rates of photodemethylation were relatively large (up to -0.25 d-1 ) but quickly decreased at depths >0.5 m below the surface. These results can be used to identify the relative importance of MeHg processes that can help guide reservoir management decisions. Environ Toxicol Chem 2021;40:1829-1839. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
Collapse
Affiliation(s)
- Chris S. Eckley
- US Environmental Protection Agency, Region-10, Seattle, Washington
| | - Todd P. Luxton
- Office of Research and Development, US Environmental Protection Agency, Cincinnati, Ohio
| | - Christopher D. Knightes
- Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island
| | - Vishal Shah
- College of the Sciences and Mathematics, West Chester University, West Chester, Pennsylvania, USA
| |
Collapse
|
2
|
Larson JH, Maki RP, Christensen VG, Hlavacek EJ, Sandheinrich MB, LeDuc JF, Kissane C, Knights BC. Mercury and water level management in lakes of northern Minnesota. Ecosphere 2021. [DOI: 10.1002/ecs2.3465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- James H. Larson
- U.S. Geological Survey Upper Midwest Environmental Sciences Center La Crosse Wisconsin54603USA
| | - Ryan P. Maki
- National Park Service Voyageurs National Park International Falls Minnesota56649USA
| | | | - Enrika J. Hlavacek
- U.S. Geological Survey Upper Midwest Environmental Sciences Center La Crosse Wisconsin54603USA
| | - Mark B. Sandheinrich
- River Studies Center University of Wisconsin‐La Crosse La Crosse Wisconsin54601USA
| | - Jaime F. LeDuc
- National Park Service Voyageurs National Park International Falls Minnesota56649USA
| | - Claire Kissane
- National Park Service Voyageurs National Park International Falls Minnesota56649USA
| | - Brent C. Knights
- U.S. Geological Survey Upper Midwest Environmental Sciences Center La Crosse Wisconsin54603USA
| |
Collapse
|
3
|
Eagles-Smith CA, Silbergeld EK, Basu N, Bustamante P, Diaz-Barriga F, Hopkins WA, Kidd KA, Nyland JF. Modulators of mercury risk to wildlife and humans in the context of rapid global change. AMBIO 2018; 47:170-197. [PMID: 29388128 PMCID: PMC5794686 DOI: 10.1007/s13280-017-1011-x] [Citation(s) in RCA: 193] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.
Collapse
Affiliation(s)
| | - Ellen K. Silbergeld
- Johns Hopkin Bloomberg School of Public Health, 615 N. Wolfe Street, E6644, Baltimore, MD 21205 USA
| | - Niladri Basu
- McGill University, 204-CINE Building, Montreal, QC H9X 3V9 Canada
| | - Paco Bustamante
- University of La Rochelle, laboratory of Littoral Environment and Societies, Littoral Environnement et Sociétés (LIENSs), LIENSs UMR 7266 CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Fernando Diaz-Barriga
- Center for Applied Research in Environment and Health at, Universidad Autonoma de San Luis Potosi, Avenida Venustiano Carranza No. 2405, Col Lomas los Filtros Código Postal, 78214 San Luis Potosí, SLP Mexico
| | - William A. Hopkins
- Department of Fish and Wildlife Conservation, 310 West Campus Drive Virginia Tech, Cheatham Hall, Room 106 (MC 0321), Blacksburg, VA 24061 USA
| | - Karen A. Kidd
- Department of Biology & School of Geography and Earth Sciences, McMaster University, 1280 Main Street W., Hamilton, ON L8S 4K1 Canada
| | - Jennifer F. Nyland
- Department of Biological Sciences, 1101 Camden Ave, Salisbury, MD 21801 USA
| |
Collapse
|
4
|
Chumchal MM, Drenner RW, Greenhill FM, Kennedy JH, Courville AE, Gober CAA, Lossau LO. Recovery of aquatic insect-mediated methylmercury flux from ponds following drying disturbance. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:1986-1990. [PMID: 28071812 DOI: 10.1002/etc.3734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/12/2016] [Accepted: 01/07/2017] [Indexed: 06/06/2023]
Abstract
Small ponds exist across a permanence gradient, and pond permanence is hypothesized to be a primary determinant of insect community structure and insect-mediated methylmercury (MeHg) flux from ponds to the surrounding terrestrial landscape. The present study describes the first experiment examining the recovery of insect-mediated MeHg flux following a drying disturbance that converted permanent ponds with insectivorous fish to semipermanent ponds without fish. Floating emergence traps were used to collect emergent insects for 10 wk in the spring and summer from 5 ponds with fish (permanent) and 5 ponds that were drained to remove fish, dried, and refilled with water (semipermanent). During the 73-d period after semipermanent ponds were refilled, total MeHg flux from semipermanent ponds was not significantly different than total MeHg flux from permanent ponds, indicating that insect-mediated MeHg flux had rapidly recovered in semipermanent ponds following the drying disturbance. Methylmercury fluxes from dragonflies (Odonata: Anisoptera) and phantom midges (Diptera: Chaoboridae) were significantly greater from newly refilled semipermanent ponds than permanent ponds, but the MeHg fluxes from the other 8 emergent insect taxa did not differ between treatments. The present study demonstrates the impact of drying disturbance and the effect of community structure on the cross-system transport of contaminants from aquatic to terrestrial ecosystems. Environ Toxicol Chem 2017;36:1986-1990. © 2017 SETAC.
Collapse
Affiliation(s)
- Matthew M Chumchal
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Ray W Drenner
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Frank M Greenhill
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - James H Kennedy
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Ashlyn E Courville
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Charlie A A Gober
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Luke O Lossau
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| |
Collapse
|
5
|
Eckley CS, Luxton TP, Goetz J, McKernan J. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 222:32-41. [PMID: 28104341 PMCID: PMC6498431 DOI: 10.1016/j.envpol.2017.01.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/15/2016] [Accepted: 01/07/2017] [Indexed: 05/26/2023]
Abstract
Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management actions can have an impact on the sediment-porewater characteristics that affect MeHg production. Such findings are also relevant to natural water systems that experience wetting and drying cycles, such as floodplains and ombrotrophic wetlands.
Collapse
Affiliation(s)
- Chris S Eckley
- US Environmental Protection Agency, Region-10. 1200, 6th Ave Seattle, WA 98101, USA
| | - Todd P Luxton
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA.
| | - Jennifer Goetz
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA
| | - John McKernan
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA
| |
Collapse
|
6
|
Willacker JJ, Eagles-Smith CA, Lutz MA, Tate MT, Lepak JM, Ackerman JT. Reservoirs and water management influence fish mercury concentrations in the western United States and Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:739-748. [PMID: 27039275 DOI: 10.1016/j.scitotenv.2016.03.050] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 06/05/2023]
Abstract
Anthropogenic manipulation of aquatic habitats can profoundly alter mercury (Hg) cycling and bioaccumulation. The impoundment of fluvial systems is among the most common habitat manipulations and is known to increase fish Hg concentrations immediately following impoundment. However, it is not well understood how Hg concentrations differ between reservoirs and lakes at large spatial and temporal scales or how reservoir management influences fish Hg concentrations. This study evaluated total Hg (THg) concentrations in 64,386 fish from 883 reservoirs and 1387 lakes, across the western United States and Canada, to assess differences between reservoirs and lakes, as well as the influence of reservoir management on fish THg concentrations. Fish THg concentrations were 1.4-fold higher in reservoirs (0.13±0.011μg/g wet weight±standard error) than lakes (0.09±0.006), though this difference varied among ecoregions. Fish THg concentrations were 1.5- to 2.6-fold higher in reservoirs than lakes of the North American Deserts, Northern Forests, and Mediterranean California ecoregions, but did not differ between reservoirs and lakes in four other ecoregions. Fish THg concentrations peaked in three-year-old reservoirs then rapidly declined in 4-12year old reservoirs. Water management was particularly important in influencing fish THg concentrations, which were up to 11-times higher in reservoirs with minimum water storage occurring in May, June, or July compared to reservoirs with minimum storage occurring in other months. Between-year changes in maximum water storage strongly influenced fish THg concentrations, but within-year fluctuations in water levels did not influence fish THg concentrations. Specifically, fish THg concentrations increased up to 3.2-fold over the range of between-year changes in maximum water storage in all ecoregions except Mediterranean California. These data highlight the role of reservoir creation and management in influencing fish THg concentrations and suggest that water management may provide an effective means of mitigating Hg bioaccumulation in some reservoirs.
Collapse
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
| | - Michelle A Lutz
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Michael T Tate
- U.S. Geological Survey, Wisconsin Water Science Center, 8505 Research Way, Middleton, WI 53562, USA
| | - Jesse M Lepak
- Colorado Parks and Wildlife, 317 West Prospect Rd., Fort Collins, CO 80526, 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
| |
Collapse
|
7
|
Chumchal MM, Drenner RW. An environmental problem hidden in plain sight? Small human-made ponds, emergent insects, and mercury contamination of biota in the Great Plains. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:1197-205. [PMID: 26013117 DOI: 10.1002/etc.2954] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/19/2015] [Accepted: 02/17/2015] [Indexed: 05/26/2023]
Abstract
Mercury (Hg) contamination of small human-made ponds and surrounding terrestrial communities may be 1 of the largest unstudied Hg-pollution problems in the United States. Humans have built millions of small ponds in the Great Plains of the United States, and these ponds have become contaminated with atmospherically deposited mercury. In aquatic ecosystems, less toxic forms of Hg deposited from the atmosphere are converted to highly toxic methylmercury (MeHg). Methylmercury is incorporated into the aquatic food web and then can be transferred to terrestrial food webs via emergent aquatic insects. The authors present a conceptual model that describes the movement of MeHg produced in aquatic ecosystems to terrestrial consumers via insects emerging from small human-made ponds. The authors hypothesize that pond permanence and the level of Hg contamination of the food web control this emergent insect-mediated flux of MeHg. The highest insect-mediated flux of MeHg is predicted to be from fishless semipermanent ponds with food webs that are highly contaminated with MeHg. Further development and testing of the conceptual model presented in the present column, particularly in the context of a changing climate, will require research at the regional, watershed, and pond scales.
Collapse
Affiliation(s)
| | - Ray W Drenner
- Biology Department, Texas Christian University, Fort Worth, Texas, USA
| |
Collapse
|