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| Ferreira Araujo, Daniel; Ponzevera, Emmanuel; Briant, Nicolas; Knoery, Joel; Sireau, Teddy; Mojtahid, Meryem; Metzger, Edouard; Brach-papa, Christophe. |
| In this work, a multi-elemental approach combining Cu and Zn stable isotopes is used to assess the metal contamination evolution in the Loire estuary bulk sediments. Elemental geochemical data indicate an increase of metal concentrations from the beginning of the industrial period peaking in the 1990s, followed by an attenuation of metal contamination inputs to the estuary. Zinc isotope compositions suggest a binary mixing process between Zn derived from terrigenous material and multi-urban anthropogenic sources. Copper isotope systematics indicate a single natural dominant source represented by weathered silicate particles from soils and rocks. This work demonstrates the applicability of Zn isotopes to identify anthropogenic Zn sources in coastal systems,... |
| Tipo: Text |
Palavras-chave: Coastal pollution; Coastal biogeochemistry; Geochemical tracers; Metal isotopes; Trace metal; Anthropogenic contamination. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00490/60188/67760.pdf |
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| Briant, Nicolas; Chouvelon, Tiphaine; Brach-papa, Christophe; Chiffoleau, Jean-francois; Savoye, Nicolas; Sonke, Jeroen; Knoery, Joel. |
| Mercury (Hg) is a natural element toxic to all living organisms. Its ocean biogeochemical cycle is dominated by atmospheric deposition, which human activities contribute to disrupt signi cantly, and to a lesser extent by riverine discharge. This element is bioamplifed and bioaccumulated in marine food webs. since mercury concentrations in some coastal animal species of high trophic level approach sanitary thresholds, understanding biogeochemical processes and mechanisms leading to these elevated Hg concentrations becomes important. The stable isotopic geochemistry of metal is indeed a very promising way to trace processes and transfers from one mercury biogeochemical reservoir to another (Sonke and Blum, 2013). The stable isotopes of Hg undergo... |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00394/50561/51253.pdf |
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| Couet, Douglas; Pringault, Olivier; Bancon-montigny, Chrystelle; Briant, Nicolas; Poulichet, Francoise Elbaz; Delpoux, Sophie; Yahia, Ons Kefi-daly; Hela, Bengharbia; Charaf, M'Rabet; Herve, Fabienne; Rovillon, Georges-augustin; Amzil, Zouher; Laabir, Mohamed. |
| Controlled laboratory experiments were conducted to test the effects of copper (Cu2+) and butyltins (BuT) on the growth, photosynthetic activity and toxin content of two HABs (Harmful Algal Blooms) dinoflagellates, the planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata. Microalgae were exposed to increasing concentrations of Cu2+ (10−4 to 31 nM) or BuT (0.084 to 84 nM) for seven days. When considering the growth, EC50 values were 0.16 (±0.09) nM and 0.03 (±0.02) nM of Cu2+ for A. catenella and O. cf. ovata, respectively. Regarding BuT, EC50 was 14.2 (±6) nM for O. cf. ovata, while A. catenella growth inhibition appeared at BuT concentrations ≥27 nM. Photosynthetic activity of the studied dinoflagellates decreased with increasing Cu and... |
| Tipo: Text |
Palavras-chave: Alexandrium catenella; Ostreopsis cf. ovata; Cu; Butyltin; Photosynthesis; Toxins. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00418/52970/53896.pdf |
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| Briant, Nicolas; Knoery, Joel; Chouvelon, Tiphaine; Brach-papa, Christophe; Chiffoleau, Jean-francois; Savoye, Nicolas; Sonke, Jeroen. |
| Mercury cycles between atmosphere, terrestrial and aquatic reservoirs through a complex combination of transport and transformation processes, until it is buried in oceanic or terrestrial sediments. Monomethylmercury is the main species bioaccumulated and bioampli ed in the food chain. Knowledge of the origin (continental, oceanicorlocalsediment)ofthisspeciesforthelittoralenvironnment can still be improved. This study focuses on ~200 samples of bivalves (mussels: Mytilus edulis and Mytilus galloprovincialis and oysters: Crassostrea gigas and Isognomon alatus) from ~80 stations along the French coast. The goals of this study were i) to describe Hg levels, speciation and isotopic composition in various bioindicator bivalves from the French coastline, and ii)... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00394/50562/51254.pdf |
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| Briant, Nicolas; Chouvelon, Tiphaine; Martinez, Laura; Brach-papa, Christophe; Chiffoleau, Jean-francois; Savoye, N.; Sonke, J.; Knoery, Joel. |
| Marine mercury (Hg) concentrations have been monitored in the French coastline for the last half a century using bivalves. The analyses presented in this study concerned 192 samples of bivalves (mussels: Mytilus edulis and Mytilus galloprovincialis and oysters: Crassostrea gigas and Isognomon alatus) from 77 sampling stations along the French coast and in the French Antilles sea. The goals of this study were to assess MeHg levels in various common bivalves from French coastline, and to identify possible geographic, taxonomic or temporal variations of concentrations. We show that the evolution of methylmercury (MeHg) concentrations covary with total mercury (HgT) concentrations. Moreover, in most of the study sites, HgT concentrations have not decreased... |
| Tipo: Text |
Palavras-chave: Mercury; Methylmercury; France; Bivalves; Speciation. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00353/46465/46398.pdf |
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| Gil-díaz, Teba; Schäfer, Jörg; Dutruch, Lionel; Bossy, Cécile; Pougnet, Frédérique; Abdou, Melina; Lerat-hardy, Antoine; Pereto, Clément; Derriennic, Hervé; Briant, Nicolas; Sireau, Teddy; Knoery, Joel; Blanc, Gerard. |
| Tellurium (Te) is a technology critical element (TCE) with largely unknown environmental behaviour, especially in continent-ocean interface systems. The unknown behaviour results from the lack of studies in aquatic environments and from analytical challenges limiting the determination of its naturally low (ultra-trace) environmental levels. We performed a comprehensive study of Te in the Lot–Garonne–Gironde fluvial–estuarine system to better understand seasonal variations, solid/liquid partitioning (Kd), gross fluxes, estuarine dynamics, and transfer to wild oysters at the estuary mouth. A temporal record (2014–2017) of dissolved (Ted) and particulate (Tep) Te concentrations at five sites in the Lot–Garonne River system shows little differences between... |
| Tipo: Text |
Palavras-chave: Garonne River; Gironde Estuary; Lot River; RNO; ROCCH; Technology critical element. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61684/65639.pdf |
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