The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Alain Boudou - One of the best experts on this subject based on the ideXlab platform.
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goldmining and Mercury Contamination of the piscivorous fish hoplias aimara in french guiana amazon basin
Ecotoxicology and Environmental Safety, 2005Co-Authors: Gilles Durrieu, Regine Maurybrachet, Alain BoudouAbstract:Abstract Mercury Contamination of 35 freshwater fish species collected from the upper part of the Petit-Saut hydroelectric reservoir (French Guiana) was analyzed in relation to their food regimes. Results showed marked biomagnification: the ratio between extreme Hg concentrations in the muscle from piscivorous species (14.3 μg/g, dry weight (dw) for Acestrorhynchus guianensis ) and herbivorous species (0.02 μg/g, dw for Myleus ternetzi ) was 715. The piscivorous species Hoplias aimara was selected to define the relationships between biometric criteria and Hg accumulation. The probability of catching a H. aimara exceeding the WHO safety limit (2.5 μgHg/g, dw) was computed from the kernel density estimator of Mercury concentrations in the muscle: for fish weighing over 1 kg (fish usually consumed), the probability was 0.93. From these results, H. aimara could be considered an indicator of Mercury biomagnification in the foodwebs and a potential risk to human populations that include this fish in their diet.
Gilles Durrieu - One of the best experts on this subject based on the ideXlab platform.
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Mercury Contamination levels in the bioindicator piscivorous fish Hoplias aimara in French Guiana rivers: mapping for risk assessment.
Environmental Science and Pollution Research, 2019Co-Authors: Régine Maury-brachet, Sophie Gentès, Emilie P. Dassié, Agnès Feurtet-mazel, Régis Vigouroux, Valérie Laperche, Patrice Gonzalez, Vincent Hanquiez, Nathalie Mesmer-dudons, Gilles DurrieuAbstract:In French Guiana, native populations present high level of Mercury Contamination, which has been linked to the consumption of contaminated fishes. The goal of this study is to undertake a cartography of Mercury Contamination levels in fishes from the six main Guiana rivers. The selected species for this study is the ubiquitous piscivorous fish Hoplias aimara. A total number of 575 fishes from 134 discrete fishing sites are regrouped into 51 river sectors. Results from this study permits to rank the six main Guiana rivers by their mean level of Contamination: Oyapock (0.548 mg kg(-1)), Comte (0.624 mg kg(-1)), Maroni (0.671 mg kg(-1)), Approuague (0.684 mg kg(-1)), Mana (0.675 mg kg(-1)), and Sinnamary (1.025 mg kg(-1)). The Contamination is however not spatially homogenous along each river, and a map of the different levels of Mercury Contamination in fishes is provided. Sectors of low mean Hg Contamination are observed both upstream (0.471 mg kg(-1)) and downstream (0.424 mg kg(-1)), corresponding to areas without any influence of gold mining activities and areas under the influence of estuarine dilution, respectively. Anoxia and gold mining activities are found to be the two main factors responsible for the high Mercury concentration in fish muscles. While mean levels of Mercury Contaminations are higher in anoxia areas (1.029 mg kg(-1)), Contaminations induced by gold mining activities (0.717 mg kg(-1)) present the most harmful consequences to human populations. No significant differences in Hg concentrations are observed between 2005 and 2014 for neither a pristine nor a gold mining area, while Hg concentration differences are observed between former (0.550 mg kg(-1)) and current gold mining sites (0.717 mg kg(-1)).
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goldmining and Mercury Contamination of the piscivorous fish hoplias aimara in french guiana amazon basin
Ecotoxicology and Environmental Safety, 2005Co-Authors: Gilles Durrieu, Regine Maurybrachet, Alain BoudouAbstract:Abstract Mercury Contamination of 35 freshwater fish species collected from the upper part of the Petit-Saut hydroelectric reservoir (French Guiana) was analyzed in relation to their food regimes. Results showed marked biomagnification: the ratio between extreme Hg concentrations in the muscle from piscivorous species (14.3 μg/g, dry weight (dw) for Acestrorhynchus guianensis ) and herbivorous species (0.02 μg/g, dw for Myleus ternetzi ) was 715. The piscivorous species Hoplias aimara was selected to define the relationships between biometric criteria and Hg accumulation. The probability of catching a H. aimara exceeding the WHO safety limit (2.5 μgHg/g, dw) was computed from the kernel density estimator of Mercury concentrations in the muscle: for fish weighing over 1 kg (fish usually consumed), the probability was 0.93. From these results, H. aimara could be considered an indicator of Mercury biomagnification in the foodwebs and a potential risk to human populations that include this fish in their diet.
George B Arhonditsis - One of the best experts on this subject based on the ideXlab platform.
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assessing Mercury Contamination patterns of fish communities in the laurentian great lakes a bayesian perspective
Environmental Pollution, 2018Co-Authors: Ariola Visha, Nilima Gandhi, Satyendra P Bhavsar, George B ArhonditsisAbstract:Abstract We examine the spatio-temporal trends of Mercury, a well-known global legacy contaminant, in eleven fish species across all of the Canadian Great Lakes. These particular fish species are selected based on their ecological, commercial, and recreational importance to the biodiversity and fishing industry of the Great Lakes. We present a two-pronged Bayesian methodological framework to rigorously assess Mercury temporal trends across multiple fish species and locations. In the first part of our analysis, we develop dynamic linear models to delineate the total Mercury levels and rates of change, while explicitly accounting for the covariance between fish length and Mercury levels in fish tissues. We then use hierarchical modelling to evaluate the spatial variability of Mercury Contamination between nearshore and offshore locations, as well as to examine the hypothesis that invasive species have induced distinct shifts on fish Mercury Contamination trends. Our analysis suggests that the general pattern across the Great Lakes was that the elevated Mercury concentrations during the 1970s had been subjected to a declining trend throughout the late 1980s/early 1990s, followed by a gradual stabilization after the late 1990s/early 2000s. The declining trend was more pronounced with top fish predators, whereas benthivorous fish species mainly underwent wax-and-wane cycles with a weaker evidence of a long-term declining trend. Historically contaminated regions, designated as Areas of Concern, and bays receiving riverine inputs are still characterized by Mercury concentrations that can lead to consumption restrictions. Lake Erie displayed the lowest Mercury levels across all the fish species examined. However, several species of commercial importance showed a reversing (increasing) trend in the 2000s, although their current levels do not pose any major concerns for consumption advisories. These recent trend reversals can be linked with systematic shifts in energy trophodynamics along with the food web alterations induced from the introduction of non-native species, and the potentially significant fluxes from the atmosphere.
Satyendra P Bhavsar - One of the best experts on this subject based on the ideXlab platform.
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assessing Mercury Contamination patterns of fish communities in the laurentian great lakes a bayesian perspective
Environmental Pollution, 2018Co-Authors: Ariola Visha, Nilima Gandhi, Satyendra P Bhavsar, George B ArhonditsisAbstract:Abstract We examine the spatio-temporal trends of Mercury, a well-known global legacy contaminant, in eleven fish species across all of the Canadian Great Lakes. These particular fish species are selected based on their ecological, commercial, and recreational importance to the biodiversity and fishing industry of the Great Lakes. We present a two-pronged Bayesian methodological framework to rigorously assess Mercury temporal trends across multiple fish species and locations. In the first part of our analysis, we develop dynamic linear models to delineate the total Mercury levels and rates of change, while explicitly accounting for the covariance between fish length and Mercury levels in fish tissues. We then use hierarchical modelling to evaluate the spatial variability of Mercury Contamination between nearshore and offshore locations, as well as to examine the hypothesis that invasive species have induced distinct shifts on fish Mercury Contamination trends. Our analysis suggests that the general pattern across the Great Lakes was that the elevated Mercury concentrations during the 1970s had been subjected to a declining trend throughout the late 1980s/early 1990s, followed by a gradual stabilization after the late 1990s/early 2000s. The declining trend was more pronounced with top fish predators, whereas benthivorous fish species mainly underwent wax-and-wane cycles with a weaker evidence of a long-term declining trend. Historically contaminated regions, designated as Areas of Concern, and bays receiving riverine inputs are still characterized by Mercury concentrations that can lead to consumption restrictions. Lake Erie displayed the lowest Mercury levels across all the fish species examined. However, several species of commercial importance showed a reversing (increasing) trend in the 2000s, although their current levels do not pose any major concerns for consumption advisories. These recent trend reversals can be linked with systematic shifts in energy trophodynamics along with the food web alterations induced from the introduction of non-native species, and the potentially significant fluxes from the atmosphere.
Regine Maurybrachet - One of the best experts on this subject based on the ideXlab platform.
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goldmining and Mercury Contamination of the piscivorous fish hoplias aimara in french guiana amazon basin
Ecotoxicology and Environmental Safety, 2005Co-Authors: Gilles Durrieu, Regine Maurybrachet, Alain BoudouAbstract:Abstract Mercury Contamination of 35 freshwater fish species collected from the upper part of the Petit-Saut hydroelectric reservoir (French Guiana) was analyzed in relation to their food regimes. Results showed marked biomagnification: the ratio between extreme Hg concentrations in the muscle from piscivorous species (14.3 μg/g, dry weight (dw) for Acestrorhynchus guianensis ) and herbivorous species (0.02 μg/g, dw for Myleus ternetzi ) was 715. The piscivorous species Hoplias aimara was selected to define the relationships between biometric criteria and Hg accumulation. The probability of catching a H. aimara exceeding the WHO safety limit (2.5 μgHg/g, dw) was computed from the kernel density estimator of Mercury concentrations in the muscle: for fish weighing over 1 kg (fish usually consumed), the probability was 0.93. From these results, H. aimara could be considered an indicator of Mercury biomagnification in the foodwebs and a potential risk to human populations that include this fish in their diet.