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Auteur Espinosa, F.; Rivera-Ingraham, G.A.
Titre Subcellular evidences of redox imbalance in well-established populations of an endangered limpet. Reasons for alarm? Type Article scientifique
Année 2016 Publication Revue Abrégée Mar. Pollut. Bull.
Volume 109 Numéro 1 Pages 72-80
Mots-Clés antioxidant enzymes; community structure; Conservation; different environmental-conditions; Heavy metals; heavy-metals; marine-invertebrates; mussel mytilus-edulis; Oxidative stress; oyster crassostrea-virginica; Patella ferruginea; patella-ferruginea gastropoda; Pollution; trace-metals
Résumé Intertidal species are more vulnerable to anthropogenic disturbances than others inhabiting subtidal and offshore habitats. Coastal development frequently results in trace-metal pollution. For endangered species such as Patella ferruginea it can be a high risk that leads local populations to extinction. Three localities were surveyed, one within a natural and unpolluted area and the other two within the harbor of Ceuta (Strait of Gibraltar), on breakwaters outside and inside. The specimens collected inside the harbor reached 3-fold higher Hg content than for those incoming from the natural area. PERMANOVA test indicated that metal composition of the specimens from inside the harbor was different from the rest. In addition, evidence of cell damage was detected in the specimens from the harbor area. This highlights the urgency of undertaking a physiological evaluation of some of the most vulnerable populations, establishing eco-physiological protocols for monitoring and managing populations settled on artificial substrata. (C) 2016 Elsevier Ltd. All rights reserved.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0025-326x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1635
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Auteur Pringault, O.; Viret, H.; Duran, R.
Titre Interactions between Zn and bacteria in marine tropical coastal sediments Type Article scientifique
Année 2012 Publication Revue Abrégée Environ. Sci. Pollut. Res.
Volume 19 Numéro 3 Pages 879-892
Mots-Clés Bacterial diversity; Metal spiking; Microcosms; New Caledonia; T-Rflp; baltic sea sediments; community; coral-reef lagoon; fragment-length-polymorphism; heavy-metals; hypersaline microbial mat; new-caledonia lagoon; polluted anoxic sediments; salins-de-giraud; south-west lagoon; tolerance pict
Résumé Purpose The main goals of this study were (1) to examine the effects of zinc on the microbial community structure of anthropogenically impacted sediments in a tropical coastal ecosystem and (2) to determine whether these microbial benthic communities may enhance the adsorption of zinc. Methods The interactions between zinc and bacteria in tropical sediments were studied in sediment microcosms amended with 2.5 mg L-1 of Zn in the water phase and incubated for 8 days under different environmental conditions, oxic/anoxic and glucose addition. At the end of incubation, microbial structure was assessed by molecular fingerprints (T-RFLP) analysis and Zn speciation in the sediment was determined by sequential extraction. Results In the three studied sediments, Zn spiking resulted in only slight changes in bacterial community structure. In contrast, the addition of low concentrations of glucose (5mM) strongly modified the bacterial community structure: <20% of similarity with the initial structure concomitant with a strong diminution of the specific richness. Overall, these results suggest that highly labile organic matter has a larger impact on microbial structure than heavy metal. These weak impacts of Zn on bacteria diversity might be partly explained by (1) the strong adsorption of Zn in the presence of bacteria and/or (2) the incorporation of Zn into a nonbioavailable fraction. Nevertheless, Zn spiking resulted in significant changes in nutrient cycles, suggesting that bacterial metabolisms were impacted by the heavy metal. This led to an increase in nutrient supplies to the water column, potentially enhancing eutrophication in a nutrient-limited, oligotrophic ecosystem.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0944-1344 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 683
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