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John H Rodgers - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory-scale evaluation of algaecide effectiveness for control of microcystin-producing cyanobacteria from Lake Okeechobee, Florida (USA)
    Ecotoxicology and environmental safety, 2020
    Co-Authors: Ciera Kinley-baird, Alyssa J Calomeni, John H Rodgers, David E. Berthold, Forrest W. Lefler, Maximiliano Barbosa, H. Dail Laughinghouse
    Abstract:

    Growth of microcystin-producing cyanobacteria in Lake Okeechobee (Florida, USA) and surrounding waters has resulted in adverse health impacts for humans and endangered species, as well as significant economic losses. As these issues worsen, there is growing pressure for efficacious solutions to rapidly mitigate harmful algal blooms (HABs) and protect critical freshwater resources. Applications of USEPA-registered Algaecides as management tactics meet many decision-making criteria often required by water resource managers (e.g., effective, scalable, selective), but have not yet been evaluated on a large scale within the Lake Okeechobee waterway. This study was conducted to bolster the peer-reviewed database for available management tactics against microcystin-producing cyanobacteria in waters of this region. Laboratory-scale experiments can be conducted first to minimize uncertainty at larger scales and improve confidence in decision-making. In this study, samples containing microcystin-producing cyanobacteria collected from Lake Okeechobee were exposed to several USEPA-registered Algaecides in laboratory toxicity experiments. Responses of target cyanobacteria were measured 3 days after treatment (DAT) in terms of cell density, chlorophyll-a concentrations, and phycocyanin concentrations. Based on responses of the cyanobacteria, minimum effective exposure concentrations were identified for each algaecide. Microcystin release (i.e. proportion of total microcystins in the aqueous phase) was measured and compared 1 DAT among effective exposures. Total microcystin concentrations were measured in effective treatments at 1, 4, and 9 DAT to discern potential for microcystin persistence following exposures to the effective formulations and exposure concentrations. Overall, several formulations including GreenClean Liquid® 5.0, GreenClean Liquid® 5.0 combined with Hydrothol® 191, and the copper-based Algaecides evaluated (Algimycin® PWF, Argos, Captain® XTR, Cutrine® Ultra, and SeClear®) achieved significant and similar effects on target cyanobacteria. The chelated copper-based formulations (Algimycin® PWF, Argos, Captain® XTR, and Cutrine® Ultra) resulted in relatively less microcystin release 1 DAT and lesser total microcystin concentrations 4 DAT. At 9 DAT, total microcystin concentrations were significantly lower than in untreated controls in all treatments evaluated. These results provide the necessary comparative performance data for preliminary decision-making and designing additional studies at larger scales. Importantly, the comparative toxicity data and approach provided in this study demonstrate the initial steps for development of site-specific management strategies for Lake Okeechobee and other areas impacted by harmful algal blooms with large spatial and temporal scales.

  • Microcystin-LR Degradation Following Copper-Based Algaecide Exposures
    Water Air & Soil Pollution, 2018
    Co-Authors: Ciera M Kinley, Andrew D Mcqueen, Alyssa J Calomeni, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Kyla J. Iwinski-wood, Monique C. Simair, John H Rodgers
    Abstract:

    When copper-based Algaecides are used in aquatic systems to decrease cyanobacteria densities, endotoxin fate is a concern, due to the potential for human health and ecological risks. Pulse exposures of Algaecides can result in episodic low dissolved oxygen (DO) concentrations (

  • Characterization of Copper Algaecide (Copper Ethanolamine) Dissipation Rates Following Pulse Exposures
    Water Air & Soil Pollution, 2017
    Co-Authors: Alyssa J Calomeni, Andrew D Mcqueen, Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, John H Rodgers
    Abstract:

    Dissipation rates of copper following algaecide treatments resulting in pulse exposures can be accurately modeled if the component dissipation rates are known. Scaled experiments (in situ, laboratory and mesocosm) were used to parse and rank dominant processes from concurrent processes affecting copper fate in pulse exposures. Copper dissipation rates were measured cumulatively in situ and in mesocosms as well as individually in laboratory experiments. Predictions of the influence of individual dissipation rates on the cumulative dissipation rate were assessed mathematically. In situ aqueous copper dissipated rapidly following an algaecide treatment, with a measured half-life of 0.03 days. Based on laboratory experiments, the most rapid copper fate process was dilution with a half-life of 0.03 days, followed by sediment sorption with a half-life of approximately 3 days. Mesocosm experiments incorporating physical characteristics of the site (i.e., dilution, sediment, algae, and site water) resulted in similar copper dissipation rates (0.02 days) relative to the in situ copper dissipation rate. Prediction of the fate of copper from algaecide treatments requires incorporation of accurate estimates of dominant fate processes that can be determined physically and mathematically.

  • Cell density dependence of Microcystis aeruginosa responses to copper algaecide concentrations: Implications for microcystin-LR release.
    Ecotoxicology and environmental safety, 2017
    Co-Authors: Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, Tyler D. Geer, John H Rodgers
    Abstract:

    Along with mechanistic models, predictions of exposure-response relationships for copper are often derived from laboratory toxicity experiments with standardized experimental exposures and conditions. For predictions of copper toxicity to algae, cell density is a critical factor often overlooked. For pulse exposures of copper-based Algaecides in aquatic systems, cell density can significantly influence copper sorbed by the algal population, and consequent responses. A cyanobacterium, Microcystis aeruginosa, was exposed to a copper-based algaecide over a range of cell densities to model the density-dependence of exposures, and effects on microcystin-LR (MC-LR) release. Copper exposure concentrations were arrayed to result in a gradient of MC-LR release, and masses of copper sorbed to algal populations were measured following exposures. While copper exposure concentrations eliciting comparable MC-LR release ranged an order of magnitude (24-h EC50s 0.03-0.3mg Cu/L) among cell densities of 106 through 107 cells/mL, copper doses (mg Cu/mg algae) were similar (24-h EC50s 0.005-0.006mg Cu/mg algae). Comparisons of MC-LR release as a function of copper exposure concentrations and doses provided a metric of the density dependence of algal responses in the context of copper-based algaecide applications. Combined with estimates of other site-specific factors (e.g. water characteristics) and fate processes (e.g. dilution and dispersion, sorption to organic matter and sediments), measuring exposure-response relationships for specific cell densities can refine predictions for in situ exposures and algal responses. These measurements can in turn decrease the likelihood of amending unnecessary copper concentrations to aquatic systems, and minimize risks for non-target aquatic organisms.

  • Influence of CuSO4 and chelated copper algaecide exposures on biodegradation of microcystin-LR.
    Chemosphere, 2017
    Co-Authors: Kyla J Iwinski, Andrew D Mcqueen, Ciera M Kinley, Alyssa J Calomeni, John H Rodgers, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Monique Haakensen
    Abstract:

    Abstract Copper exposures from algaecide applications in aquatic systems are hypothesized to impede bacterial degradation of microcystin (MC), a cyanobacterial produced hepatotoxin. Despite regulatory implications of this hypothesis, limited data exist on influences of copper-exposures on MC-degrading bacteria and consequent MC-degradation. In this study, influences of copper-algaecide concentrations and formulations on bacterial composition and microcystin-LR (MCLR) degradation were investigated. Microcystis aeruginosa was exposed to four concentrations (0–5.0 mg Cu L−1) of three copper-algaecide formulations, and rates and extents of MCLR degradation were measured. In untreated controls and following exposures of 0.1, 0.5, and 1.0 mg Cu L−1, MCLR concentrations decreased at a rate of ∼41–53 μg MCLR/L d−1. Following exposure to 5.0 mg Cu L−1 MCLR degradation rates decreased an order of magnitude to ∼3–7 μg MCLR/L d−1. Bacterial diversity decreased following copper-exposures greater than 0.1 mg Cu L−1 for all formulations. Relative abundance of certain groups of MC-degrading bacteria identified in treatments increased with increasing copper concentration, suggesting they may be less sensitive to copper exposures than other, MCLR and non MC-degrading heterotrophic bacteria present in the assemblage. Results from this study revealed that copper concentration can influence degradation rates of MCLR, however this influence was not significant within copper concentrations currently registered for use (≤1.0 mg Cu L−1) of the tested Algaecides. Copper formulation did not significantly alter degradation rates or bacterial composition. These data augment our understanding of the influences of copper algaecide-exposures on MCLR degradation, and can be used to inform more accurate risk evaluations and use of copper-Algaecides for management of MCLR-producing cyanobacteria.

Alyssa J Calomeni - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory-scale evaluation of algaecide effectiveness for control of microcystin-producing cyanobacteria from Lake Okeechobee, Florida (USA)
    Ecotoxicology and environmental safety, 2020
    Co-Authors: Ciera Kinley-baird, Alyssa J Calomeni, John H Rodgers, David E. Berthold, Forrest W. Lefler, Maximiliano Barbosa, H. Dail Laughinghouse
    Abstract:

    Growth of microcystin-producing cyanobacteria in Lake Okeechobee (Florida, USA) and surrounding waters has resulted in adverse health impacts for humans and endangered species, as well as significant economic losses. As these issues worsen, there is growing pressure for efficacious solutions to rapidly mitigate harmful algal blooms (HABs) and protect critical freshwater resources. Applications of USEPA-registered Algaecides as management tactics meet many decision-making criteria often required by water resource managers (e.g., effective, scalable, selective), but have not yet been evaluated on a large scale within the Lake Okeechobee waterway. This study was conducted to bolster the peer-reviewed database for available management tactics against microcystin-producing cyanobacteria in waters of this region. Laboratory-scale experiments can be conducted first to minimize uncertainty at larger scales and improve confidence in decision-making. In this study, samples containing microcystin-producing cyanobacteria collected from Lake Okeechobee were exposed to several USEPA-registered Algaecides in laboratory toxicity experiments. Responses of target cyanobacteria were measured 3 days after treatment (DAT) in terms of cell density, chlorophyll-a concentrations, and phycocyanin concentrations. Based on responses of the cyanobacteria, minimum effective exposure concentrations were identified for each algaecide. Microcystin release (i.e. proportion of total microcystins in the aqueous phase) was measured and compared 1 DAT among effective exposures. Total microcystin concentrations were measured in effective treatments at 1, 4, and 9 DAT to discern potential for microcystin persistence following exposures to the effective formulations and exposure concentrations. Overall, several formulations including GreenClean Liquid® 5.0, GreenClean Liquid® 5.0 combined with Hydrothol® 191, and the copper-based Algaecides evaluated (Algimycin® PWF, Argos, Captain® XTR, Cutrine® Ultra, and SeClear®) achieved significant and similar effects on target cyanobacteria. The chelated copper-based formulations (Algimycin® PWF, Argos, Captain® XTR, and Cutrine® Ultra) resulted in relatively less microcystin release 1 DAT and lesser total microcystin concentrations 4 DAT. At 9 DAT, total microcystin concentrations were significantly lower than in untreated controls in all treatments evaluated. These results provide the necessary comparative performance data for preliminary decision-making and designing additional studies at larger scales. Importantly, the comparative toxicity data and approach provided in this study demonstrate the initial steps for development of site-specific management strategies for Lake Okeechobee and other areas impacted by harmful algal blooms with large spatial and temporal scales.

  • Microcystin-LR Degradation Following Copper-Based Algaecide Exposures
    Water Air & Soil Pollution, 2018
    Co-Authors: Ciera M Kinley, Andrew D Mcqueen, Alyssa J Calomeni, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Kyla J. Iwinski-wood, Monique C. Simair, John H Rodgers
    Abstract:

    When copper-based Algaecides are used in aquatic systems to decrease cyanobacteria densities, endotoxin fate is a concern, due to the potential for human health and ecological risks. Pulse exposures of Algaecides can result in episodic low dissolved oxygen (DO) concentrations (

  • Characterization of Copper Algaecide (Copper Ethanolamine) Dissipation Rates Following Pulse Exposures
    Water Air & Soil Pollution, 2017
    Co-Authors: Alyssa J Calomeni, Andrew D Mcqueen, Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, John H Rodgers
    Abstract:

    Dissipation rates of copper following algaecide treatments resulting in pulse exposures can be accurately modeled if the component dissipation rates are known. Scaled experiments (in situ, laboratory and mesocosm) were used to parse and rank dominant processes from concurrent processes affecting copper fate in pulse exposures. Copper dissipation rates were measured cumulatively in situ and in mesocosms as well as individually in laboratory experiments. Predictions of the influence of individual dissipation rates on the cumulative dissipation rate were assessed mathematically. In situ aqueous copper dissipated rapidly following an algaecide treatment, with a measured half-life of 0.03 days. Based on laboratory experiments, the most rapid copper fate process was dilution with a half-life of 0.03 days, followed by sediment sorption with a half-life of approximately 3 days. Mesocosm experiments incorporating physical characteristics of the site (i.e., dilution, sediment, algae, and site water) resulted in similar copper dissipation rates (0.02 days) relative to the in situ copper dissipation rate. Prediction of the fate of copper from algaecide treatments requires incorporation of accurate estimates of dominant fate processes that can be determined physically and mathematically.

  • Influence of CuSO4 and chelated copper algaecide exposures on biodegradation of microcystin-LR.
    Chemosphere, 2017
    Co-Authors: Kyla J Iwinski, Andrew D Mcqueen, Ciera M Kinley, Alyssa J Calomeni, John H Rodgers, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Monique Haakensen
    Abstract:

    Abstract Copper exposures from algaecide applications in aquatic systems are hypothesized to impede bacterial degradation of microcystin (MC), a cyanobacterial produced hepatotoxin. Despite regulatory implications of this hypothesis, limited data exist on influences of copper-exposures on MC-degrading bacteria and consequent MC-degradation. In this study, influences of copper-algaecide concentrations and formulations on bacterial composition and microcystin-LR (MCLR) degradation were investigated. Microcystis aeruginosa was exposed to four concentrations (0–5.0 mg Cu L−1) of three copper-algaecide formulations, and rates and extents of MCLR degradation were measured. In untreated controls and following exposures of 0.1, 0.5, and 1.0 mg Cu L−1, MCLR concentrations decreased at a rate of ∼41–53 μg MCLR/L d−1. Following exposure to 5.0 mg Cu L−1 MCLR degradation rates decreased an order of magnitude to ∼3–7 μg MCLR/L d−1. Bacterial diversity decreased following copper-exposures greater than 0.1 mg Cu L−1 for all formulations. Relative abundance of certain groups of MC-degrading bacteria identified in treatments increased with increasing copper concentration, suggesting they may be less sensitive to copper exposures than other, MCLR and non MC-degrading heterotrophic bacteria present in the assemblage. Results from this study revealed that copper concentration can influence degradation rates of MCLR, however this influence was not significant within copper concentrations currently registered for use (≤1.0 mg Cu L−1) of the tested Algaecides. Copper formulation did not significantly alter degradation rates or bacterial composition. These data augment our understanding of the influences of copper algaecide-exposures on MCLR degradation, and can be used to inform more accurate risk evaluations and use of copper-Algaecides for management of MCLR-producing cyanobacteria.

  • Cellular and aqueous microcystin-LR following laboratory exposures of Microcystis aeruginosa to copper Algaecides.
    Chemosphere, 2016
    Co-Authors: Kyla J Iwinski, Alyssa J Calomeni, Tyler D. Geer, John H Rodgers
    Abstract:

    Microcystin release from algal cells influences use of copper-Algaecides in water resources. Accurate data regarding relationships between copper-algaecide exposures and responses of microcystin-producing algae are needed to make informed management decisions. Responses of Microcystis aeruginosa were measured in terms of cellular microcystin-LR (MC-LR), aqueous MC-LR, and chlorophyll-a following exposure to CuSO4 and copper-ethanolamine. Comparisons were made between treated and untreated samples, and copper formulations. EC50s and slopes for M. aeruginosa responses to copper exposures were calculated. Algal responses followed a sigmoidal exposure-response relationship, and cellular MC-LR and chlorophyll-a were negatively related to copper concentrations. Aqueous MC-LR increased with copper concentrations, although the increase in aqueous MC-LR was not proportional to decreases in cellular MC-LR and chlorophyll-a. Cellular MC-LR and chlorophyll a declined at a greater rate than aqueous MC-LR increased. Total MC-LR was less than untreated controls following copper exposure. Differences were measured between copper formulations in terms of aqueous and total MC-LR concentrations at concentrations of 0.5 and 1.0 mg Cu L-1. Aqueous and total MC-LR were greater (10-20%) following exposure to CuSO4 compared to copper-ethanolamine one day following exposure. The positive relationship between copper concentration and aqueous MC-LR at 0.07-1.0 mg Cu L-1 demonstrates that lower copper concentrations were as effective as higher concentrations in controlling M. aeruginosa while decreasing the total amount of MC-LR, and minimizing the proportion of MC-LR released to the aqueous-phase. Results serve to support more accurate risk evaluations of MC-LR concentrations when M. aeruginosa is exposed to copper-Algaecides and when it is untreated.

Kyla J Iwinski - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of Copper Algaecide (Copper Ethanolamine) Dissipation Rates Following Pulse Exposures
    Water Air & Soil Pollution, 2017
    Co-Authors: Alyssa J Calomeni, Andrew D Mcqueen, Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, John H Rodgers
    Abstract:

    Dissipation rates of copper following algaecide treatments resulting in pulse exposures can be accurately modeled if the component dissipation rates are known. Scaled experiments (in situ, laboratory and mesocosm) were used to parse and rank dominant processes from concurrent processes affecting copper fate in pulse exposures. Copper dissipation rates were measured cumulatively in situ and in mesocosms as well as individually in laboratory experiments. Predictions of the influence of individual dissipation rates on the cumulative dissipation rate were assessed mathematically. In situ aqueous copper dissipated rapidly following an algaecide treatment, with a measured half-life of 0.03 days. Based on laboratory experiments, the most rapid copper fate process was dilution with a half-life of 0.03 days, followed by sediment sorption with a half-life of approximately 3 days. Mesocosm experiments incorporating physical characteristics of the site (i.e., dilution, sediment, algae, and site water) resulted in similar copper dissipation rates (0.02 days) relative to the in situ copper dissipation rate. Prediction of the fate of copper from algaecide treatments requires incorporation of accurate estimates of dominant fate processes that can be determined physically and mathematically.

  • Cell density dependence of Microcystis aeruginosa responses to copper algaecide concentrations: Implications for microcystin-LR release.
    Ecotoxicology and environmental safety, 2017
    Co-Authors: Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, Tyler D. Geer, John H Rodgers
    Abstract:

    Along with mechanistic models, predictions of exposure-response relationships for copper are often derived from laboratory toxicity experiments with standardized experimental exposures and conditions. For predictions of copper toxicity to algae, cell density is a critical factor often overlooked. For pulse exposures of copper-based Algaecides in aquatic systems, cell density can significantly influence copper sorbed by the algal population, and consequent responses. A cyanobacterium, Microcystis aeruginosa, was exposed to a copper-based algaecide over a range of cell densities to model the density-dependence of exposures, and effects on microcystin-LR (MC-LR) release. Copper exposure concentrations were arrayed to result in a gradient of MC-LR release, and masses of copper sorbed to algal populations were measured following exposures. While copper exposure concentrations eliciting comparable MC-LR release ranged an order of magnitude (24-h EC50s 0.03-0.3mg Cu/L) among cell densities of 106 through 107 cells/mL, copper doses (mg Cu/mg algae) were similar (24-h EC50s 0.005-0.006mg Cu/mg algae). Comparisons of MC-LR release as a function of copper exposure concentrations and doses provided a metric of the density dependence of algal responses in the context of copper-based algaecide applications. Combined with estimates of other site-specific factors (e.g. water characteristics) and fate processes (e.g. dilution and dispersion, sorption to organic matter and sediments), measuring exposure-response relationships for specific cell densities can refine predictions for in situ exposures and algal responses. These measurements can in turn decrease the likelihood of amending unnecessary copper concentrations to aquatic systems, and minimize risks for non-target aquatic organisms.

  • Influence of CuSO4 and chelated copper algaecide exposures on biodegradation of microcystin-LR.
    Chemosphere, 2017
    Co-Authors: Kyla J Iwinski, Andrew D Mcqueen, Ciera M Kinley, Alyssa J Calomeni, John H Rodgers, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Monique Haakensen
    Abstract:

    Abstract Copper exposures from algaecide applications in aquatic systems are hypothesized to impede bacterial degradation of microcystin (MC), a cyanobacterial produced hepatotoxin. Despite regulatory implications of this hypothesis, limited data exist on influences of copper-exposures on MC-degrading bacteria and consequent MC-degradation. In this study, influences of copper-algaecide concentrations and formulations on bacterial composition and microcystin-LR (MCLR) degradation were investigated. Microcystis aeruginosa was exposed to four concentrations (0–5.0 mg Cu L−1) of three copper-algaecide formulations, and rates and extents of MCLR degradation were measured. In untreated controls and following exposures of 0.1, 0.5, and 1.0 mg Cu L−1, MCLR concentrations decreased at a rate of ∼41–53 μg MCLR/L d−1. Following exposure to 5.0 mg Cu L−1 MCLR degradation rates decreased an order of magnitude to ∼3–7 μg MCLR/L d−1. Bacterial diversity decreased following copper-exposures greater than 0.1 mg Cu L−1 for all formulations. Relative abundance of certain groups of MC-degrading bacteria identified in treatments increased with increasing copper concentration, suggesting they may be less sensitive to copper exposures than other, MCLR and non MC-degrading heterotrophic bacteria present in the assemblage. Results from this study revealed that copper concentration can influence degradation rates of MCLR, however this influence was not significant within copper concentrations currently registered for use (≤1.0 mg Cu L−1) of the tested Algaecides. Copper formulation did not significantly alter degradation rates or bacterial composition. These data augment our understanding of the influences of copper algaecide-exposures on MCLR degradation, and can be used to inform more accurate risk evaluations and use of copper-Algaecides for management of MCLR-producing cyanobacteria.

  • Cellular and aqueous microcystin-LR following laboratory exposures of Microcystis aeruginosa to copper Algaecides.
    Chemosphere, 2016
    Co-Authors: Kyla J Iwinski, Alyssa J Calomeni, Tyler D. Geer, John H Rodgers
    Abstract:

    Microcystin release from algal cells influences use of copper-Algaecides in water resources. Accurate data regarding relationships between copper-algaecide exposures and responses of microcystin-producing algae are needed to make informed management decisions. Responses of Microcystis aeruginosa were measured in terms of cellular microcystin-LR (MC-LR), aqueous MC-LR, and chlorophyll-a following exposure to CuSO4 and copper-ethanolamine. Comparisons were made between treated and untreated samples, and copper formulations. EC50s and slopes for M. aeruginosa responses to copper exposures were calculated. Algal responses followed a sigmoidal exposure-response relationship, and cellular MC-LR and chlorophyll-a were negatively related to copper concentrations. Aqueous MC-LR increased with copper concentrations, although the increase in aqueous MC-LR was not proportional to decreases in cellular MC-LR and chlorophyll-a. Cellular MC-LR and chlorophyll a declined at a greater rate than aqueous MC-LR increased. Total MC-LR was less than untreated controls following copper exposure. Differences were measured between copper formulations in terms of aqueous and total MC-LR concentrations at concentrations of 0.5 and 1.0 mg Cu L-1. Aqueous and total MC-LR were greater (10-20%) following exposure to CuSO4 compared to copper-ethanolamine one day following exposure. The positive relationship between copper concentration and aqueous MC-LR at 0.07-1.0 mg Cu L-1 demonstrates that lower copper concentrations were as effective as higher concentrations in controlling M. aeruginosa while decreasing the total amount of MC-LR, and minimizing the proportion of MC-LR released to the aqueous-phase. Results serve to support more accurate risk evaluations of MC-LR concentrations when M. aeruginosa is exposed to copper-Algaecides and when it is untreated.

  • Analysis of Algaecide Exposures: an Evaluation of the I_3 ^− Method to Measure Sodium Carbonate Peroxyhydrate Algaecides
    Water Air & Soil Pollution, 2015
    Co-Authors: Ciera M Kinley, Andrew D Mcqueen, Kyla J Iwinski, John H Rodgers, Alyssa J Calomeni
    Abstract:

    Algaecides are commonly used to control noxious algal growths in water resources. In order to make accurate predictions about responses of target and non-target species to algaecide exposures, reliable methods are needed to confirm exposures in the laboratory and the field. The focus of this research was to evaluate the I_3 ^− method for measuring hydrogen peroxide (H_2O_2) exposures associated with applications of a sodium carbonate peroxyhydrate (SCP)-based algaecide. To meet this overall objective, method detection limits, interferences from field waters (turbidity, color, and algal cell density), and storage stability of samples were measured. The method detection limits were 0.2 ( p  

Ciera M Kinley - One of the best experts on this subject based on the ideXlab platform.

  • Microcystin-LR Degradation Following Copper-Based Algaecide Exposures
    Water Air & Soil Pollution, 2018
    Co-Authors: Ciera M Kinley, Andrew D Mcqueen, Alyssa J Calomeni, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Kyla J. Iwinski-wood, Monique C. Simair, John H Rodgers
    Abstract:

    When copper-based Algaecides are used in aquatic systems to decrease cyanobacteria densities, endotoxin fate is a concern, due to the potential for human health and ecological risks. Pulse exposures of Algaecides can result in episodic low dissolved oxygen (DO) concentrations (

  • Characterization of Copper Algaecide (Copper Ethanolamine) Dissipation Rates Following Pulse Exposures
    Water Air & Soil Pollution, 2017
    Co-Authors: Alyssa J Calomeni, Andrew D Mcqueen, Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, John H Rodgers
    Abstract:

    Dissipation rates of copper following algaecide treatments resulting in pulse exposures can be accurately modeled if the component dissipation rates are known. Scaled experiments (in situ, laboratory and mesocosm) were used to parse and rank dominant processes from concurrent processes affecting copper fate in pulse exposures. Copper dissipation rates were measured cumulatively in situ and in mesocosms as well as individually in laboratory experiments. Predictions of the influence of individual dissipation rates on the cumulative dissipation rate were assessed mathematically. In situ aqueous copper dissipated rapidly following an algaecide treatment, with a measured half-life of 0.03 days. Based on laboratory experiments, the most rapid copper fate process was dilution with a half-life of 0.03 days, followed by sediment sorption with a half-life of approximately 3 days. Mesocosm experiments incorporating physical characteristics of the site (i.e., dilution, sediment, algae, and site water) resulted in similar copper dissipation rates (0.02 days) relative to the in situ copper dissipation rate. Prediction of the fate of copper from algaecide treatments requires incorporation of accurate estimates of dominant fate processes that can be determined physically and mathematically.

  • Cell density dependence of Microcystis aeruginosa responses to copper algaecide concentrations: Implications for microcystin-LR release.
    Ecotoxicology and environmental safety, 2017
    Co-Authors: Ciera M Kinley, Kyla J Iwinski, Maas Hendrikse, Tyler D. Geer, John H Rodgers
    Abstract:

    Along with mechanistic models, predictions of exposure-response relationships for copper are often derived from laboratory toxicity experiments with standardized experimental exposures and conditions. For predictions of copper toxicity to algae, cell density is a critical factor often overlooked. For pulse exposures of copper-based Algaecides in aquatic systems, cell density can significantly influence copper sorbed by the algal population, and consequent responses. A cyanobacterium, Microcystis aeruginosa, was exposed to a copper-based algaecide over a range of cell densities to model the density-dependence of exposures, and effects on microcystin-LR (MC-LR) release. Copper exposure concentrations were arrayed to result in a gradient of MC-LR release, and masses of copper sorbed to algal populations were measured following exposures. While copper exposure concentrations eliciting comparable MC-LR release ranged an order of magnitude (24-h EC50s 0.03-0.3mg Cu/L) among cell densities of 106 through 107 cells/mL, copper doses (mg Cu/mg algae) were similar (24-h EC50s 0.005-0.006mg Cu/mg algae). Comparisons of MC-LR release as a function of copper exposure concentrations and doses provided a metric of the density dependence of algal responses in the context of copper-based algaecide applications. Combined with estimates of other site-specific factors (e.g. water characteristics) and fate processes (e.g. dilution and dispersion, sorption to organic matter and sediments), measuring exposure-response relationships for specific cell densities can refine predictions for in situ exposures and algal responses. These measurements can in turn decrease the likelihood of amending unnecessary copper concentrations to aquatic systems, and minimize risks for non-target aquatic organisms.

  • Influence of CuSO4 and chelated copper algaecide exposures on biodegradation of microcystin-LR.
    Chemosphere, 2017
    Co-Authors: Kyla J Iwinski, Andrew D Mcqueen, Ciera M Kinley, Alyssa J Calomeni, John H Rodgers, Maas Hendrikse, Tyler D. Geer, Jenny Liang, Vanessa Friesen, Monique Haakensen
    Abstract:

    Abstract Copper exposures from algaecide applications in aquatic systems are hypothesized to impede bacterial degradation of microcystin (MC), a cyanobacterial produced hepatotoxin. Despite regulatory implications of this hypothesis, limited data exist on influences of copper-exposures on MC-degrading bacteria and consequent MC-degradation. In this study, influences of copper-algaecide concentrations and formulations on bacterial composition and microcystin-LR (MCLR) degradation were investigated. Microcystis aeruginosa was exposed to four concentrations (0–5.0 mg Cu L−1) of three copper-algaecide formulations, and rates and extents of MCLR degradation were measured. In untreated controls and following exposures of 0.1, 0.5, and 1.0 mg Cu L−1, MCLR concentrations decreased at a rate of ∼41–53 μg MCLR/L d−1. Following exposure to 5.0 mg Cu L−1 MCLR degradation rates decreased an order of magnitude to ∼3–7 μg MCLR/L d−1. Bacterial diversity decreased following copper-exposures greater than 0.1 mg Cu L−1 for all formulations. Relative abundance of certain groups of MC-degrading bacteria identified in treatments increased with increasing copper concentration, suggesting they may be less sensitive to copper exposures than other, MCLR and non MC-degrading heterotrophic bacteria present in the assemblage. Results from this study revealed that copper concentration can influence degradation rates of MCLR, however this influence was not significant within copper concentrations currently registered for use (≤1.0 mg Cu L−1) of the tested Algaecides. Copper formulation did not significantly alter degradation rates or bacterial composition. These data augment our understanding of the influences of copper algaecide-exposures on MCLR degradation, and can be used to inform more accurate risk evaluations and use of copper-Algaecides for management of MCLR-producing cyanobacteria.

  • Analysis of Algaecide Exposures: an Evaluation of the I_3 ^− Method to Measure Sodium Carbonate Peroxyhydrate Algaecides
    Water Air & Soil Pollution, 2015
    Co-Authors: Ciera M Kinley, Andrew D Mcqueen, Kyla J Iwinski, John H Rodgers, Alyssa J Calomeni
    Abstract:

    Algaecides are commonly used to control noxious algal growths in water resources. In order to make accurate predictions about responses of target and non-target species to algaecide exposures, reliable methods are needed to confirm exposures in the laboratory and the field. The focus of this research was to evaluate the I_3 ^− method for measuring hydrogen peroxide (H_2O_2) exposures associated with applications of a sodium carbonate peroxyhydrate (SCP)-based algaecide. To meet this overall objective, method detection limits, interferences from field waters (turbidity, color, and algal cell density), and storage stability of samples were measured. The method detection limits were 0.2 ( p  

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  • biomass of the cyanobacterium lyngbya wollei alters copper algaecide exposure and risks to a non target organism
    Bulletin of Environmental Contamination and Toxicology, 2020
    Co-Authors: West M Bishop, Ben E Willis, Gregory W Cope, Robert J Richardson
    Abstract:

    Nuisance algal infestations are increasing globally in distribution and frequency. Copper-based Algaecides are routinely applied to control these infestations, though there is an ever-present concern of risks to non-target species. This research evaluated risks associated with a commonly applied chelated copper algaecide (Captain® XTR; SePRO Corporation) to a sentinel non-target species (Daphnia magna) and further assessed alteration of the exposure and toxicity when a nuisance mat-forming cyanobacterium, Lyngbya wollei, was present in exposures. Aqueous copper concentrations in treatments with algae significantly decreased within 1 h after treatment and averaged 57.5% of nominal amended Cu through the experiment duration. The 48 h LC50 values were 371 µg Cu/L with no algae present in exposures and increased significantly to 531 µg Cu/L when L. wollei was simultaneously exposed. This research provides information on the short-term fate of copper and hazard assessment by incorporating targeted binding ligands, as present in operational treatments.

  • Controlling Lyngbya wollei in three Alabama, USA reservoirs: summary of a long-term management program
    Applied Water Science, 2019
    Co-Authors: Wesley T. Anderson, West M Bishop, Ben E Willis, Josh N. Yerby, Jason Carlee, C. Todd Horton
    Abstract:

    Large-scale Lyngbya wollei (Cyanobacteria, Oscillatoriales) infestations are increasing throughout the USA and globally and causing significant obstruction of water resource uses. Decision makers and stakeholders encountering this nuisance organism often seek management options. Many approaches to L. wollei management may be ineffective or not applicable to specific field sites. Chemical control with United States Environmental Protection Agency registered Algaecides has shown to be effective, although the specific formulation, concentration, and application frequency can all govern efficacy. This study summarizes results from a long-term and adaptive management program on extensive L. wollei infestations in three central Alabama, USA reservoirs (Lay Lake, Jordan Lake and Lake Mitchell) managed by Alabama Power Company. Multiple treatment strategies including numerous Algaecides, combinations and addition of surfactants were used in attempts to control the nuisance cyanobacterium and preserve multiple beneficial functions of the resource. Ultimately, operational shift toward one technology, a double-chelated copper algaecide with surfactants and emulsifiers (Captain^® XTR) resulted in more efficient and economical control. There were significant ( P  

  • Modulating the Effect of Iron and Total Organic Carbon on the Efficiency of a Hydrogen Peroxide-Based Algaecide for Suppressing Cyanobacteria
    Water Air & Soil Pollution, 2019
    Co-Authors: Elizabeth A. Crafton, West M Bishop, Teresa J. Cutright, Donald W. Ott
    Abstract:

    The intensity and frequency of cyanobacteria-dominated harmful algal blooms (cHABs) has been increasing. A key issue associated with cHABs is the potential to release cyanotoxins, such as microcystin. One of the primary methods for addressing cHABs in a reservoir is the application of Algaecides. This research evaluated the impact of common environmental factors (i.e., Fe, total organic carbon) on the efficacy of a hydrogen peroxide-based algaecide to attain control of a targeted cyanobacterial population. The results found that sodium carbonate peroxydrate (SCP, trade name PAK®27) at half the manufacturer’s suggested application was effective at suppressing cyanobacteria for 2 weeks. For example, reactors that contained a full level of TOC and 1 mg/L Fe significantly decreased by 89% from 21,899 to 2437 ± 987 cells/mL ( p  

  • Comparison of Partitioning and Efficacy Between Copper Algaecide Formulations: Refining the Critical Burden Concept
    Water Air & Soil Pollution, 2018
    Co-Authors: West M Bishop, Robert J Richardson, Ben E Willis
    Abstract:

    Filamentous mat-forming algae are increasingly impairing freshwater resources. To restore water utility, reactive management programs often involve application of copper-based Algaecides. Copper algaecide formulations can differ significantly, and this research outlined an advanced approach to evaluate formulation efficiency for controlling filamentous algae. Two common algal species (Lyngbya wollei, Pithophora varia) were used to assess copper internalization and adsorption as well as relation to control among copper formulations. Captain® XTR achieved control (7-day EC85) of L. wollei with internal copper concentrations of 0.78 and 0.76 mg Cu/g based on chlorophyll a content or filament viability, respectively. Cutrine® Ultra achieved control of L. wollei based on filament viability only at 0.85 mg Cu/g. Internalized copper concentrations required for control following Captain XTR exposures were similar for P. varia, 0.81 and 0.95 mg Cu/g, whereas Cutrine Ultra and copper sulfate did not elicit control nor attain the critical internal copper threshold. The relationship between internalized copper and responses, among all formulations, was significant (P < 0.0001) with R2 values of 0.920 and 0.935 for L. wollei and 0.807 and 0.826 for P. varia based on filament viability and chlorophyll a content, respectively. Formulation efficiency, internalized copper versus total amended, was greatest with Captain XTR (average 0.17), followed by Cutrine Ultra (0.13), and copper sulfate (0.09). By measuring the efficiency of a specific algaecide and the corresponding amount required to achieve control of targeted algal biomass, management objectives can be achieved while decreasing environmental loads of copper, number of treatments, and operational costs.

  • the presence of algae mitigates the toxicity of copper based Algaecides to a nontarget organism
    Environmental Toxicology and Chemistry, 2018
    Co-Authors: West M Bishop, Ben E Willis, Robert J Richardson, Gregory W Cope
    Abstract:

    Copper-based Algaecides are routinely applied to target noxious algal blooms in freshwaters. Standard toxicity testing data with copper suggest that typical concentrations used to control algae can cause deleterious acute impacts to nontarget organisms. These "clean" water experiments lack algae, which are specifically targeted in field applications of Algaecides and contain competing ligands. The present research measured the influence of algae on algaecide exposure and subsequent response of the nontarget species Daphnia magna to copper sulfate and an ethanolamine-chelated copper algaecide (Captain®). Significant shifts (p < 0.05) in D. magna 48-h median lethal concentration (LC50) values were found when algae were present in exposures along with a copper salt or a chelated copper formulation. Copper sulfate 48-h LC50 values shifted from 75.3 to 317.8 and 517.8 μg Cu/L, whereas Captain increased from 353.8 to 414.2 and 588.5 μg Cu/L in no algae, 5 × 105 , and 5 × 106 cells/mL algae treatments, respectively. Larger shifts were measured with copper sulfate exposures, although Captain was less toxic to D. magna in all corresponding treatments. Captain was more effective at controlling Scenedesmus dimorphus at most concentrations, and control was inversely proportional to toxicity to D. magna. Overall, incorporating target competing ligands (i.e., algae) into standard toxicity testing is important for accurate risk assessment, and copper formulation can significantly alter algaecidal efficacy and risks to nontarget organisms. Environ Toxicol Chem 2018;37:2132-2142. © 2018 SETAC.