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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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| Tallobre, Cedric; Loncke, Lies; Bassetti, Maria-angela; Giresse, Pierre; Bayon, Germain; Buscail, Roselyne; De Madron, Xavier Durrieu; Bourrin, Francois; Vanhaesebroucke, Marc; Sotin, Christine. |
| The Demerara Plateau, belonging to the passive transform margin of French Guiana, was investigated during the IGUANES cruise in 2013. The objectives of the cruise were to explore the poorly-known surficial sedimentary column overlying thick mass transport deposits as well as to understand the factors controlling recent sedimentation. The presence of numerous bedforms at the seafloor was observed thanks to newly acquired IGUANES bathymetric, high resolution seismic and chirp data, while sediment cores allowed the characterization of the deposits covering the mass transport deposits. Modern oceanographic conditions were determined in situ, using mooring monitoring over a 10-month period. Our data indicate the presence of a Contourite Depositional System... |
| Tipo: Text |
Palavras-chave: Marginal plateau; Contourite; Comet tail; Demerara Plateau. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00308/41957/41220.pdf |
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| Tallobre, Cédric; Giresse, Pierre; Bassetti, Maria-angela; Loncke, Lies; Bayon, Germain; Buscail, Roselyne; Tudryn, Alina; Zaragosi, Sébastien. |
| The Demerara Plateau is a marginal plateau which forms a bathymetric relief on the sea floor. Here, contourite deposits have been studied in detail, following the recent discovery of contourite sequences likely related to the bottom currents and linked both to contour current and peculiar sea-floor morphology. A chronostratigraphic framework, based on δ18O relative variations and palaeomagnetic events in sediment cores allows correlating sediment processes to current intensity changes and major climate phases (glacial or interglacial). The studied sediments are enriched in glauconitic grains. In addition, the glauconite mineralogical maturity can easily correlate to low sedimentation rate and slightly energetic bottom currents on the seafloor. Based on... |
| Tipo: Text |
Palavras-chave: Marginal plateau; Contourite; Glauconite; Demerara plateau. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00485/59665/62724.pdf |
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| Bassetti, Maria-angela; Berne, Serge; Sicre, Marie-alexandrine; Dennielou, Bernard; Alonso, Yoann; Buscail, Roselyne; Jalali, Bassem; Hebert, Bertil; Menniti, Christophe. |
| Expanded marine Holocene archives are relatively scarce in the Mediterranean Sea because most of the sediments were trapped in catchment areas during this period. Mud belts are the most suitable targets to access expanded Holocene records. These sedimentary bodies represent excellent archives for the study of sea-land interactions and notably the impact of the hydrological activity on sediment accumulation. We retrieved a 7.2m long sediment core from the Rhone mud belt in the Gulf of Lions in an area where the average accumulation rate is ca. 0.70 m 1000 yr(-1). This core thus provides a continuous and high-resolution record of the last 10 ka cal BP. A multiproxy dataset (XRF core scan, C-14 dates, grain size and organic-matter analysis) combined with... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00352/46360/45981.pdf |
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| Kim, Jung-hyun; Buscail, Roselyne; Fanget, Anne-sophie; Eyrolle-boyer, Frederique; Bassetti, Maria-angela; Dorhout, Denise; Baas, Marianne; Berne, Serge; Damste, Jaap S. Sinninghe. |
| We tested the applicability of the BIT (branched and isoprenoid tetraether) index as a proxy for palaeoflood events in the river-dominated continental margin of the Gulf of Lions (NW Mediterranean). We compared the concentrations of branched glycerol dialkyl glycerol tetraethers (br GDGTs) and crenarchaeol in suspended particulate matter (SPM) collected downstream in the Rhône River, as well as in surface sediments and a ca. 8m piston core from the Rhône prodelta. The core covered the last 400 yr, with four distinct intervals recording the river influence under natural and man-induced shifts in four main channels of the river mouth (Bras de Fer, Grand Rhône, Pégoulier,and Roustan). The results indicate that there are mixed sources of br GDGTs and... |
| Tipo: Text |
Palavras-chave: Palaeoflood; BIT index; GDGTs; Rhone prodelta. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00198/30969/29345.pdf |
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| Ritt, Benedicte; Desbruyeres, Daniel; Caprais, Jean-claude; Gauthier, Olivier; Ruffine, Livio; Buscail, Roselyne; Olu-le Roy, Karine; Sarrazin, Jozee. |
| The Mediterranean Sea constitutes a unique environment to study cold-seep ecosystems due to the presence of different geodynamic settings, from an active margin along the Mediterranean Ridge (MR) to a passive margin in the Nile Deep-Sea Fan (NDSF). We attempted to identify the structure of benthic communities associated with the Napoli and Amsterdam mud volcanoes (MVs) located on the MR and to establish the links between faunal distribution and environmental conditions at different spatial scales. Comparison between the 2 MVs revealed that the faunal distribution seemed to be mainly controlled by the characteristics of the microhabitats. On both geological structures, the variability between the different microhabitats was higher than the variability... |
| Tipo: Text |
Palavras-chave: Mediterranean Ridge; Cold seeps; Benthic fauna; Environmental conditions; Diversity indices; Microhabitats. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00106/21725/19292.pdf |
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| Cossa, Daniel; De Madron, Xavier Durrieu; Schafer, Jorg; Lanceleur, Laurent; Guedron, Stephane; Buscail, Roselyne; Thomas, Bastien; Castelle, Sabine; Naudin, Jean-jacques. |
| Despite the ecologic and economical importance of coastal areas, the neurotoxic bioaccumulable monomethylmercury (MMHg) fluxes within the ocean margins and exchanges with the open sea remain unassessed. The aim of this paper is to address the questions of the abundance, distribution, production and exchanges of methylated mercury species (MeHgT), including MMHg and dimethylmercury (DMHg), in the waters, atmosphere and sediments of the Northwestern Mediterranean margin including the Rhône River delta, the continental shelf and its slope (Gulf of Lions) and the adjacent open sea (North Gyre). Concentrations of MeHgT ranged from <0.02 to 0.48 pmol L−1 with highest values associated with the oxygen-deficient zone of the open sea. The methylated mercury to... |
| Tipo: Text |
Palavras-chave: Mercury; Methylmercury; Ocean margin; Coastal area; Mediterranean. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00363/47399/47477.pdf |
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| Toyofuku, Takashi; Duros, Pauline; Fontanier, Christophe; Mamo, Briony; Bichon, Sabrina; Buscail, Roselyne; Chabaud, Gerard; Deflandre, Bruno; Goubet, Sarah; Gremare, Antoine; Menniti, Christophe; Fujii, Minami; Kawamura, Kiichiro; Koho, Karoliina Annika; Noda, Atsushi; Namegaya, Yuichi; Oguri, Kazumasa; Radakovitch, Olivier; Murayama, Masafumi; De Nooijer, Lennart Jan; Kurasawa, Atushi; Ohkawara, Nina; Okutani, Takashi; Sakaguchi, Arito; Jorissen, Frans; Reichart, Gert-jan; Kitazato, Hiroshi. |
| On March 11th, 2011 the Mw 9.0 2011 Tohoku-Oki earthquake resulted in a tsunami which caused major devastation in coastal areas. Along the Japanese NE coast, tsunami waves reached maximum run-ups of 40 m, and travelled kilometers inland. Whereas devastation was clearly visible on land, underwater impact is much more difficult to assess. Here, we report unexpected results obtained during a research cruise targeting the seafloor off Shimokita (NE Japan), shortly (five months) after the disaster. The geography of the studied area is characterized by smooth coastline and a gradually descending shelf slope. Although high-energy tsunami waves caused major sediment reworking in shallow-water environments, investigated shelf ecosystems were characterized by... |
| Tipo: Text |
Palavras-chave: Palaeoceanography; Biodiversity. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00248/35914/34453.pdf |
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