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Carla M. Koretsky - One of the best experts on this subject based on the ideXlab platform.
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The influence of Road Salt on seasonal mixing, redox stratification and methane concentrations in urban kettle lakes.
The Science of the total environment, 2019Co-Authors: Danielle Dupuis, Emily Sprague, Kathryn M. Docherty, Carla M. KoretskyAbstract:Abstract Influxes of saline water from Roads treated with deicers can alter the density structure of urban lakes. This can diminish or halt turnover events, such that lakes may transition from dimixis to monomixis or meromixis. In nutrient-rich lakes, this lack of turnover can produce persistent hypolimnetic anoxia. We hypothesized that diminished turnover in urban lakes impacted by Road Salt inputs would lead to increased accumulation of methane in the hypolimnia, with the potential for greater release of methane to the atmosphere via ebullition and from larger storage fluxes of methane when turnover events do occur. The lake water columns of two urban lakes (Woods Lake and Asylum Lake), previously suggested to have transitioned to meromixis and monomixis because of Road Salt deicer inputs, were sampled monthly from March 2016 to June 2017. A nearby rural lake (North Lake) less likely to be impacted by Road Salt and maintaining seasonal mixing, was also sampled for comparison. Lake column water was analyzed for conductivity, temperature, dissolved oxygen, ferrous iron, manganese, sulfide, calcium, magnesium, sodium, chloride and methane concentrations as a function of depth. All three lakes are eutrophic with at least seasonally anoxic hypolimnia. Our data are consistent with prior studies suggesting that Woods Lake has transitioned to meromixis and Asylum Lake to monomixis due to an influx of dense saline water from Roads treated with deicers. In contrast, rural North Lake, which had much lower chloride, sodium and conductivity levels, was dimictic. The diminished or absent turnover in the two urban lakes during fall and spring resulted in persistently anoxic, redox-stratified hypolimnia, with much larger accumulations of methane compared to the rural lake. This study demonstrates that Road Salt deicers impact lake mixing and biogeochemistry, especially methane concentrations, with the potential for significant increases in greenhouse gas emissions from urban lakes.
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Effects of Road Salt deicers on an urban groundwater-fed kettle lake
Applied Geochemistry, 2018Co-Authors: D. Allie Wyman, Carla M. KoretskyAbstract:Abstract Road Salt deicers significantly influence the chemistry and physical mixing of urban lakes, even causing transition from dimixis to monomixis or meromixis. In this study, the water column geochemistry of Asylum Lake, a primarily groundwater-fed, eutrophic kettle lake in urban Kalamazoo, MI, was monitored for over a year to determine the extent of Road Salt deicer influence on the lake chemistry and the physical mixing of the lake. Water column samples from the surface to the deepest part of Asylum Lake were analyzed monthly for nineteen months for a suite of parameters including dissolved oxygen, pH, conductivity, temperature, alkalinity, Fe2+, Mn2+, orthophosphate, total NH4+, alkalinity, total sulfide, Cl−, SO42−, Ca2+, Mg2+, K+, and Na+. During the study period, spring mixing was never observed and a nearly complete fall turnover was observed only in November 2013. The hypolimnion of Asylum Lake was always hypoxic or anoxic and redox-stratified, with seasonal development of suboxic and sulfidic zones, which were disrupted in fall and winter following partial fall turnover and subsequent ice cover. This study suggests that Road Salt deicers have caused Asylum Lake to transition from dimixis to meromixis or periodic monomixis with significant consequences for biogeochemical cycles in the lake waters.
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Cultural meromixis: Effects of Road Salt on the chemical stratification of an urban kettle lake
Chemical Geology, 2015Co-Authors: Ryan Sibert, Carla M. Koretsky, D. Allie WymanAbstract:Abstract Saline runoff from application of Road Salt deicers has the potential to create persistent density gradients in urban freshwater lakes, resulting in significant changes to physical mixing and biogeochemical cycling. In this study, the seasonal influence of Road Salt influx on the geochemical cycling of a small, urban kettle lake is examined. Water column samples were collected approximately twice per month for fifteen months and analyzed for temperature, pH, conductivity, major ions, nutrients and redox-sensitive solutes. The lake water column was redox-stratified with high concentrations of dissolved Mn(II), Fe(II), ammonium, phosphate and, during some periods, sulfide and methane in the hypolimnion. Bottom water anoxia was persistent throughout the entire sampling period. Concentrations of sodium and chloride, which correlated strongly with conductivity, were over a hundred times greater compared with levels in nearby rural lakes. Conductivity, chloride and calculated density profiles indicated the presence of a pycnocline at ~ 9 m depth that persisted throughout the sampling period. The chemical data demonstrate that Road Salt input has caused the lake to become meromictic, with a complete lack of fall and spring turnover.
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Effects of Road Salt deicers on sediment biogeochemistry
Biogeochemistry, 2012Co-Authors: Seon Young Kim, Carla M. KoretskyAbstract:Road Salt deicers, especially NaCl and CaCl2, are increasingly applied to paved areas throughout the world. The goal of this study is to investigate the influence of high concentrations of these Salts on wetland biogeochemistry. Sediment cores were collected in fall and spring from a freshwater wetland fringing an urban kettle lake (Asylum Lake, Kalamazoo, MI, USA), and incubated for 100 days in deionized water (control) or with treatments of 1 or 5 g/L CaCl2·2H2O or 5 g/L NaCl to simulate addition of Road Salt deciers. At monthly intervals, cores were sliced into three depths (0–5, 5–10, 10–15 cm) and pore waters extracted for analysis of pH, total alkalinity and dissolved Mn(II), Fe(II), PO4−3, NH3, H2S, SO4−2, Na, K, Mg, and Ca. Changes in solid phase geochemistry were assessed by measuring the percent organic matter and the distribution of Fe and Mn among four operationally defined sediment fractions (exchangeable, carbonate, reducible, oxidizable) in the control and treatment cores. Addition of NaCl, and especially CaCl2, stimulated significant growth of microbial mats at the core sediment–water interface and led to decreased pH and increased concentrations of Mn(II), Fe(II) and exchangeable cations (Ca, Mg, K, Na) in the sediment pore waters. This study demonstrates that the influx of Road Salt deciers is likely to have a significant impact on biogeochemical cycling in wetland sediments.
Rick A Relyea - One of the best experts on this subject based on the ideXlab platform.
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The Combined Effects of Road Salt and Biotic Stressors on Amphibian Sex Ratios.
Environmental toxicology and chemistry, 2020Co-Authors: Sagan Leggett, Devin K. Jones, Jonathan Borrelli, Rick A RelyeaAbstract:Aquatic systems worldwide are threatened by the anthropogenic use of synthetic chemicals, including pesticides, pharmaceuticals, and Road deicers. Exposure to contaminants can alter the behavior, morphology, and physiology of organisms if it occurs during sensitive life stages. For instance, past studies have documented feminization of male amphibians following herbicide exposure and skewed sex ratios among amphibian populations exposed to Road Salt. Yet, many of these studies lack the complexities found within natural environments, such as competition with conspecifics or threat of predation, which are also known to influence development. Thus, it is important to understand how anthropogenic and natural stressors interact to alter animal sex ratios. Given the growing concern of secondary salinization of freshwater systems, we exposed larval wood frogs (Rana sylvatica) to either Road Salt (NaCl) or an alternative Salt mixture (NaCl, MgCl2 , KCl) at three concentrations (200, 600, 1000 mg Cl- /L) crossed with three biotic stressors (no-stressor control, competition, or predator cues) to examine their potentially interactive effects on sex. Exposure to biotic stressors and NaCl did not influence wood frog sex ratios. In contrast, tadpole exposure to the intermediate Salt mixture concentration significantly reduced the proportion of female frogs. Future studies need to determine whether such changes in sex are widespread among sensitive species with complex life cycles, and assess the consequences of sex ratio changes on long-term population dynamics. This article is protected by copyright. All rights reserved.
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Cascading effects of insecticides and Road Salt on wetland communities.
Environmental pollution (Barking Essex : 1987), 2020Co-Authors: Jacquelyn L. Lewis, Gabriela Agostini, Devin K. Jones, Rick A RelyeaAbstract:Novel stressors introduced by human activities increasingly threaten freshwater ecosystems. The annual application of more than 2.3 billion kg of pesticide active ingredient and 22 billion kg of Road Salt has led to the contamination of temperate waterways. While pesticides and Road Salt are known to cause direct and indirect effects in aquatic communities, their possible interactive effects remain widely unknown. Using outdoor mesocosms, we created wetland communities consisting of zooplankton, phytoplankton, periphyton, and leopard frog (Rana pipiens) tadpoles. We evaluated the toxic effects of six bRoad-spectrum insecticides from three families (neonicotinoids: thiamethoxam, imidacloprid; organophosphates: chlorpyrifos, malathion; pyrethroids: cypermethrin, permethrin), as well as the potentially interactive effects of four of these insecticides with three concentrations of Road Salt (NaCl; 44, 160, 1600 Cl- mg/L). Organophosphate exposure decreased zooplankton abundance, elevated phytoplankton biomass, and reduced tadpole mass whereas exposure to neonicotinoids and pyrethroids decreased zooplankton abundance but had no significant effect on phytoplankton abundance or tadpole mass. While organophosphates decreased zooplankton abundance at all Salt concentrations, effects on phytoplankton abundance and tadpole mass were dependent upon Salt concentration. In contrast, while pyrethroids had no effects in the absence of Salt, they decreased zooplankton and phytoplankton density under increased Salt concentrations. Our results highlight the importance of multiple-stressor research under natural conditions. As human activities continue to imperil freshwater systems, it is vital to move beyond single-stressor experiments that exclude potentially interactive effects of chemical contaminants.
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A review of the species, community, and ecosystem impacts of Road Salt salinisation in fresh waters
Freshwater Biology, 2019Co-Authors: William D. Hintz, Rick A RelyeaAbstract:Freshwater ecosystems worldwide are threatened by salinisation caused by human activities. Scientific attention on the ecological impacts of salinisation from Road deicing Salts is increasing exponentially. Spanning multiple trophic levels and ecosystem types, we review and synthesise the ecological impacts of Road Salt in freshwater ecosystems to understand species‐, community‐, and ecosystem‐level responses. In our review, we identify knowledge gaps that we hope will motivate future research directions. We found that Road Salts negatively affect species at all trophic levels, from biofilms to fish. The concentration at which Road Salt triggered an effect varied considerably. Species‐level impacts were generally sub‐lethal, leading to reductions in growth and reproduction, which can be magnified by natural stressors such as predation. Community‐level impacts including reductions of biodiversity were common, leading to communities of Salt‐tolerant species, which may have implications for disease transmission from enhanced recruitment of Salt‐tolerant host species such as mosquitoes. At the ecosystem level, Road Salts alter nutrient and energy flow. Contaminated wetlands could see greater export of greenhouse gases, streams will probably export more nitrogen and carbon, and lakes will encounter altered hydrology and oxygen dynamics, leading to greater phosphorus release from sediments. While it is necessary to keep Roads safe for humans, the costs to freshwater ecosystems may be severe if actions are not taken to mitigate Road Salt salinisation. Cooperation among policy makers, environmental managers, transportation professionals, scientists, and the public will be crucial to prevent a loss of ecosystem services including water clarity, drinkable water, recreation venues, and fisheries.
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interactive effects of Road Salt and leaf litter on wood frog sex ratios and sexual size dimorphism
Canadian Journal of Fisheries and Aquatic Sciences, 2017Co-Authors: Max R Lambert, Rick A Relyea, Aaron B Stoler, Meredith S Smylie, David K SkellyAbstract:Myriad natural and anthropogenic chemicals alter aquatic vertebrate sex ratios, with implications for population dynamics. Despite 22 million metric tons of Salt applied to US Roads annually, with much of it entering aquatic environments, it is unknown whether Salt impacts sex ratios. Moreover, changes in forest composition co-occur with increased Road Salt application, dramatically changing ecosystems. We explore how Road Salt (sodium chloride) and two leaf litter types might influence amphibian development. By examining wood frog (Rana sylvatica = Lithobates sylvaticus) metamorphs reared with different combinations of Salt (114 and 867 mg Cl·L−1) and litter species (none, maple (Acer rubrum), oak (Quercus spp.)), we show that Salt masculinizes tadpole sex ratios, whereas oak, but not maple, litter feminizes populations. Road Salt addition eliminates sexual dimorphism in oak-reared tadpoles, but enhances sexual size dimorphisms in maple-reared tadpoles, producing larger females. We are the first to show ...
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Leaf litter mediates the negative effect of Road Salt on forested wetland communities
Freshwater Science, 2017Co-Authors: Aaron B Stoler, Devin K. Jones, William D. Hintz, Lovisa Lind, Brian M. Mattes, Matthew S. Schuler, Rick A RelyeaAbstract:AbstractHuman modification of landscapes has substantially altered the quality and quantity of terrestrial subsidies to freshwater ecosystems. The same modifications frequently lead to addition of chemical contaminants to freshwater environments. Both types of environmental change can alter the abundance of species and can lead to ecological interactions that affect entire communities. We examined how variation of tree litter inputs interacts with inputs of Road Salt deicers, which are an increasingly common contaminant in northern latitudes. Based on studies of the effects of each factor in isolation, we hypothesized that elevated Cl− levels would reduce copepod densities, increase algal abundance, and subsequently increase Salt-tolerant consumer densities and biomass. We also hypothesized that these effects would be most pronounced in the presence of highly soluble leaf litter (e.g., Acer rubrum). We constructed experimental freshwater ponds containing assemblages of phytoplankton, periphyton, zooplankt...
J.j. Zwiazek - One of the best experts on this subject based on the ideXlab platform.
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Long-term impact of Road Salt (NaCl) on soil and urban trees in Edmonton, Canada
Urban Forestry and Urban Greening, 2017Co-Authors: M.a. Equiza, Maria Monica Calvo-polanco, D. Cirelli, J. Señorans, M. Wartenbe, C. Saunders, J.j. ZwiazekAbstract:Long-term impact of Road Salt (NaCl) on soil and urban trees in Edmonton, Canada
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long term impact of Road Salt nacl on soil and urban trees in edmonton canada
Urban Forestry & Urban Greening, 2017Co-Authors: M.a. Equiza, D. Cirelli, J. Señorans, M. Wartenbe, C. Saunders, Maria Monica Calvopolanco, J.j. ZwiazekAbstract:Abstract The application of de-icing Salts for winter Road maintenance is recognized as a major contributor to the decline of urban trees. We conducted a long-term monitoring program across several locations in the City of Edmonton (Alberta, Canada) to evaluate the impact of Roadway Salt application on tree species widely planted in boulevards and right-of-ways: Ulmus americana , Fraxinus pennsylvanica , Pinus contorta , and Picea glauca . Soil and leaf samples were collected from a total of 16 sites over six years. There were four sites selected for each tree species: three mid- to high- traffic Roadside sites that received regular winter maintenance and one non-serviced site (control). Sampling was performed three times per year from late spring to late summer. Airborne salinity was assessed in four locations at different distances from the Road. In 50% of the Roadside sites, soil electrical conductivity (EC) values exceeded 2 dS m −1 . Soil pH in all of the Roadside sites was also significantly higher than in the control sites, with values ranging from 7.6 to 8.5. In all four species, trees growing in sites with high soil EC had increased leaf Na concentrations and reduced leaf chlorophyll concentrations. Among the airborne monitoring sites, Na deposition in high traffic locations was over four-fold higher than those measured in the control location. Furthermore, Na levels remained relatively high at 20–50 m from the main Road. Our data suggest that while soil salinity is among the main stressors affecting Roadside trees in Edmonton, Salt spray deposition may also have a significant impact on trees located close to high vehicle traffic areas and dense Road networks. Our study highlights the importance of collecting data over several years and from multiple locations to account for the spatial and temporal heterogeneity of the urban environments in order to better evaluate the impact of Road Salt application on urban trees.
D. Allie Wyman - One of the best experts on this subject based on the ideXlab platform.
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Effects of Road Salt deicers on an urban groundwater-fed kettle lake
Applied Geochemistry, 2018Co-Authors: D. Allie Wyman, Carla M. KoretskyAbstract:Abstract Road Salt deicers significantly influence the chemistry and physical mixing of urban lakes, even causing transition from dimixis to monomixis or meromixis. In this study, the water column geochemistry of Asylum Lake, a primarily groundwater-fed, eutrophic kettle lake in urban Kalamazoo, MI, was monitored for over a year to determine the extent of Road Salt deicer influence on the lake chemistry and the physical mixing of the lake. Water column samples from the surface to the deepest part of Asylum Lake were analyzed monthly for nineteen months for a suite of parameters including dissolved oxygen, pH, conductivity, temperature, alkalinity, Fe2+, Mn2+, orthophosphate, total NH4+, alkalinity, total sulfide, Cl−, SO42−, Ca2+, Mg2+, K+, and Na+. During the study period, spring mixing was never observed and a nearly complete fall turnover was observed only in November 2013. The hypolimnion of Asylum Lake was always hypoxic or anoxic and redox-stratified, with seasonal development of suboxic and sulfidic zones, which were disrupted in fall and winter following partial fall turnover and subsequent ice cover. This study suggests that Road Salt deicers have caused Asylum Lake to transition from dimixis to meromixis or periodic monomixis with significant consequences for biogeochemical cycles in the lake waters.
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Cultural meromixis: Effects of Road Salt on the chemical stratification of an urban kettle lake
Chemical Geology, 2015Co-Authors: Ryan Sibert, Carla M. Koretsky, D. Allie WymanAbstract:Abstract Saline runoff from application of Road Salt deicers has the potential to create persistent density gradients in urban freshwater lakes, resulting in significant changes to physical mixing and biogeochemical cycling. In this study, the seasonal influence of Road Salt influx on the geochemical cycling of a small, urban kettle lake is examined. Water column samples were collected approximately twice per month for fifteen months and analyzed for temperature, pH, conductivity, major ions, nutrients and redox-sensitive solutes. The lake water column was redox-stratified with high concentrations of dissolved Mn(II), Fe(II), ammonium, phosphate and, during some periods, sulfide and methane in the hypolimnion. Bottom water anoxia was persistent throughout the entire sampling period. Concentrations of sodium and chloride, which correlated strongly with conductivity, were over a hundred times greater compared with levels in nearby rural lakes. Conductivity, chloride and calculated density profiles indicated the presence of a pycnocline at ~ 9 m depth that persisted throughout the sampling period. The chemical data demonstrate that Road Salt input has caused the lake to become meromictic, with a complete lack of fall and spring turnover.
M.a. Equiza - One of the best experts on this subject based on the ideXlab platform.
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Long-term impact of Road Salt (NaCl) on soil and urban trees in Edmonton, Canada
Urban Forestry and Urban Greening, 2017Co-Authors: M.a. Equiza, Maria Monica Calvo-polanco, D. Cirelli, J. Señorans, M. Wartenbe, C. Saunders, J.j. ZwiazekAbstract:Long-term impact of Road Salt (NaCl) on soil and urban trees in Edmonton, Canada
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long term impact of Road Salt nacl on soil and urban trees in edmonton canada
Urban Forestry & Urban Greening, 2017Co-Authors: M.a. Equiza, D. Cirelli, J. Señorans, M. Wartenbe, C. Saunders, Maria Monica Calvopolanco, J.j. ZwiazekAbstract:Abstract The application of de-icing Salts for winter Road maintenance is recognized as a major contributor to the decline of urban trees. We conducted a long-term monitoring program across several locations in the City of Edmonton (Alberta, Canada) to evaluate the impact of Roadway Salt application on tree species widely planted in boulevards and right-of-ways: Ulmus americana , Fraxinus pennsylvanica , Pinus contorta , and Picea glauca . Soil and leaf samples were collected from a total of 16 sites over six years. There were four sites selected for each tree species: three mid- to high- traffic Roadside sites that received regular winter maintenance and one non-serviced site (control). Sampling was performed three times per year from late spring to late summer. Airborne salinity was assessed in four locations at different distances from the Road. In 50% of the Roadside sites, soil electrical conductivity (EC) values exceeded 2 dS m −1 . Soil pH in all of the Roadside sites was also significantly higher than in the control sites, with values ranging from 7.6 to 8.5. In all four species, trees growing in sites with high soil EC had increased leaf Na concentrations and reduced leaf chlorophyll concentrations. Among the airborne monitoring sites, Na deposition in high traffic locations was over four-fold higher than those measured in the control location. Furthermore, Na levels remained relatively high at 20–50 m from the main Road. Our data suggest that while soil salinity is among the main stressors affecting Roadside trees in Edmonton, Salt spray deposition may also have a significant impact on trees located close to high vehicle traffic areas and dense Road networks. Our study highlights the importance of collecting data over several years and from multiple locations to account for the spatial and temporal heterogeneity of the urban environments in order to better evaluate the impact of Road Salt application on urban trees.
