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Cossa, Daniel; Garnier, Cedric; Buscail, Roselyne; Elbaz-poulichet, Francoise; Mikac, Nevenka; Patel-sorrentino, Nathalie; Tessier, Erwan; Rigaud, Sylvain; Lenoble, Veronique; Gobeil, Charles. |
Methylation of mercury (Hg) is the crucial process that controls Hg biomagnification along the aquatic food chains. Aquatic sediments are of particular interest because they constitute an essential reservoir where inorganic divalent Hg (HgII) is methylated. Methylmercury (MeHg) concentrations in sediments mainly result from the balance between methylation and demethylation reactions, two opposite natural processes primarily mediated by aquatic microorganisms. Thus, Hg availability and the activity of methylating microbial communities control the MeHg abundance in sediments. Consistently, some studies have reported a significant positive correlation between MeHg and HgII or total Hg (HgT), taken as a proxy for HgII, in aquatic sediments using... |
Tipo: Text |
Palavras-chave: Mercury; Methylmercury; Aquatic sediment; Methylation; Demethylation. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28220/26520.pdf |
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Huy Dang, Duc; Schafer, Jörg; Brach-papa, Christophe; Lenoble, Veronique; Durrieu, Gael; Dutruch, Lionel; Chiffoleau, Jean-francois; Gonzalez, Jean-louis; Blanc, Gerard; Mullot, Jean-ulrich; Mounier, Stephane; Garnier, Cedric. |
Heavily contaminated sediments are a serious concern for ecosystem quality, especially in coastal areas, where vulnerability is high due to intense anthropogenic pressure. Surface sediments (54 stations), 50 cm interface cores (five specific stations), river particles, coal and bulk Pb plate from past French Navy activities, seawater and mussels were collected in Toulon Bay (NW Mediterranean Sea). Lead content and Pb stable isotope composition have evidenced the direct impact of sediment pollution stock on both the water column quality and the living organisms, through the specific Pb isotopic signature in these considered compartments. The history of pollution events including past and present contaminant dispersion in Toulon Bay were also demonstrated by... |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00288/39884/38624.pdf |
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Rigaud, Sylvain; Radakovitch, Olivier; Couture, Raoul-marie; Deflandre, Bruno; Cossa, Daniel; Garnier, Cedric; Garnie, Jean-marie. |
The early diagenesis of the major carrier phases (Fe and Mn minerals), trace elements (As, Co, Cr, Hg, MeHg, Ni) and nutrients (Sigma NO3, NH4+, Sigma PO4) and their exchange at the sediment water/interface were studied in the Berre Lagoon, a Mediterranean lagoon in France, at one site under two contrasting oxygenation conditions (strictly anoxic and slightly oxic) and at an adjacent site with perennially well-oxygenated water. From the concentration profiles of the primary biogeochemical constituents and trace elements of the pore and bottom waters, as well as the total and reactive particulate phases, it was possible to locate and identify the diagenetic reactions controlling the mobility of trace elements in the sediments and quantify their rates by... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00134/24555/23573.pdf |
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Abdou, Melina; Schafer, Jorg; Hu, Ruoyu; Gil-diaz, Teba; Garnier, Cedric; Brach-papa, Christophe; Chiffoleau, Jean-francois; Charmasson, Sabine; Giner, Franck; Dutruch, Lionel; Blanc, Gerard. |
Platinum (Pt) is considered a Technology Critical Element (TCE) and an emerging metallic contaminant with increasing release into the environment. Gaps in knowledge and understanding of environmental levels, fate and effects of Pt still exist, especially in the marine environment. This work presents Pt concentrations in the northwestern Mediterranean coast including: (i) temporal variability from sediment cores and farmed mussels in the Toulon Bay (historically affected by intense human activities) and (ii) spatial distribution from recent wild mussels collected along ∼ 300 km coastline with contrasting ecosystems (including natural reserves), quantified using voltammetry and inductively coupled plasma-mass spectrometry. The historical (> 100 years)... |
Tipo: Text |
Palavras-chave: Platinum; Sediments; Mussels; Biomonitoring; Mediterranean coast. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00460/57134/59055.pdf |
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