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Registros recuperados: 13 | |
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Michel, Pierre; Boutier, Bernard; Herbland, Alain; Averty, Bernard; Artigas, Lf; Auger, Dominique; Chartier, E. |
The arsenic (As) cycle in the marine environment is known to be sensitive to biological activity. Within the scope of the National Coastal Oceanography Program, we undertook a specific study of the behaviour of this element in a water column on the continental shelf of the Bay of Biscay off the Gironde estuary during two oceanographic cruises conducted in May 1994 and May 1995. Various chemical forms were measured: arsenite (As3), at-senate (As5), monomethylarsenic (MMA), dimethylarsenic (DMA) and dissolved total As after ultraviolet mineralization. The net flux of total As from the Gironde estuary was evaluated as well as its effect on the concentration in surface marine waters. The vertical profiles in the coastal zone during a period of active primary... |
Tipo: Text |
Palavras-chave: Arsenic; Phytoplankton; Speciation; Gironde plume; Biscay Bay. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-851.pdf |
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Michel, Pierre; Averty, Bernard; Noel, Joelle; Sanjuan, Jane. |
In order to estimate arsenic flux from the English Channel toward the North Sea, 168 samples were obtained from September 1990 to November 1991 along a transect between Boulogne and Folkestone comprising six stations and two depths. Organic and inorganic arsenic were measured in dissolved phase and total arsenic in suspended particles. The mean concentration of dissolved total arsenic in water was 1.38 +/- 0.12 mug.l-1. The variability of measured concentrations was low, particularly for the four intermediate stations. Results were slightly more sensitive for English (1.38 +/- 0.12 mug.l-1) and French (135 +/- 0.11 mug.l-1) coastal stations due to exchanges with shallower sediments. Dissolved organic arsenic was nearly negligible from December to March... |
Tipo: Text |
Palavras-chave: ARSENIC MMA; DMA TRACE ELEMENTS ENGLISH CHANNEL NORTH SEA. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21079/18704.pdf |
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Lahbib, Youssef; Abidli, Sami; Chiffoleau, Jean-francois; Averty, Bernard; El Menif, Najoua Trigui. |
We have assessed for the first time the current status of tributyltin (TBT) contamination in Hexaplex trunculus along Tunisian coastal waters. Two sampling campaigns have been performed in July 2004 and July 2007 at seven different sites. The snails were analyzed for imposex status, i.e. Imposex incidence, Relative Penis Length Index (RPLI) and Vas Deferens Sequence Index (VDSI), followed by the quantification of butyltins in their tissues. Imposex was detected in six populations from the 2004 samples and in five populations from the 2007 samples. The imposex incidence ranged from 0 (no imposex) to 100%, the RPLI from 0 to 56.7 and the VDSI from 0 to 4.4. TBT was also detected in six populations in 2004 and five populations in 2007. The concentrations... |
Tipo: Text |
Palavras-chave: Tunisia; Imposex; Hexaplex trunculus; TBT; Tributyltin. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6499.pdf |
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Cossa, Daniel; Heimbuerger, Lars-eric; Lannuzel, Delphine; Rintoul, Stephen R.; Butler, Edward C. V.; Bowie, Andrew R.; Averty, Bernard; Watson, Roslyn J.; Remenyi, Tomas. |
We present here the first mercury speciation study in the water column of the Southern Ocean, using a high-resolution south-to-north section (27 stations from 65.50 degrees S to 44.00 degrees S) with up to 15 depths (0-4440 m) between Antarctica and Tasmania (Australia) along the 140 degrees E meridian. In addition, in order to explore the role of sea ice in Hg cycling, a study of mercury speciation in the "snow-sea ice-seawater" continuum was conducted at a coastal site, near the Australian Casey station (66.40 degrees S; 101.14 degrees E). In the open ocean waters, total Hg (Hg(T)) concentrations varied from 0.63 to 2.76 pmol L(-1) with "transient-type" vertical profiles and a latitudinal distribution suggesting an atmospheric mercury source south of the... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15221/12677.pdf |
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Heimbuerger, Lars-eric; Cossa, Daniel; Marty, Jean-claude; Migon, Christophe; Averty, Bernard; Dufour, Aurelie; Ras, Josephine. |
Recent findings on the distribution of methylated mercury (MeHgT) in waters have highlighted the importance of organic carbon remineralization on the production of these compounds in the open ocean. Here, we present the first time-series (20 monthly samplings between July 2007 and May 2009) of high-resolution vertical profiles (10-12 depths in a 2350 m water column) of MeHgT distributions in an open ocean environment, the Ligurian Sea (North-western Mediterranean Sea). Concentrations varied within the sub-picomolar range (general mean: 0.30 0.17 pmol L-1, n = 214) with the lowest values at the surface, increasing with depth up to the oxygen minimum zone, and decreasing slowly at greater depth. Concentrations in the surface waters never exceeded 0.15 pmol... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12415/9225.pdf |
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Larose, Catheririe; Dommergue, Aurelien; De Angelis, Martine; Cossa, Daniel; Averty, Bernard; Marusczak, Nicolas; Soumis, Nicolas; Schneider, Dominique; Ferrari, Christophe. |
Seasonal snow is an active media and an important climate factor that governs nutrient transfer in Arctic ecosystems. Since the snow stores and transforms nutrients and contaminants, it is of crucial importance to gain a better understanding of the dynamics of contaminant cycling within the snowpack and its subsequent release to catchments via meltwater. Over the course of a two-month field study in the spring of 2008, we collected snow and meltwater samples from a seasonal snowpack in Ny-Alesund, Norway (78 degrees 56'N, 11 degrees 52'E), which were analyzed for major inorganic ions and some organic acids, as well as total, dissolved, bioavailable mercury (THg, DHg, BioHg, respectively) and monomethylmercury (MMHg) species. We observe a seasonal gradient... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00018/12904/9880.pdf |
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Registros recuperados: 13 | |
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