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| Registros recuperados: 31 | |
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| Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| A new Fine Scale Sampler (FSS) was designed and used in the Loire River plume (Bay of Biscay, France) in order to study phytoplankton distribution in highly stratified water columns. The FSS consists of a linear array of 15 sampling bottles, set horizontally at 20 cm intervals. Data acquired from the CTD and fluorescence probe of the FSS enable it to be precisely positioned at the depth of the highest density gradient or at the chlorophyll a maximum. The FSS made it possible to investigate fine scale vertical distribution of phytoplankton and relationships with water density, nutrient concentrations or light availability, for spring and summer conditions. Under spring conditions, the entire upper layer exhibited a dominant diatom population (Chaetoceros... |
| Tipo: Text |
Palavras-chave: Plankton patchiness; Density discontinuity; Sampling; Thin layer; Nutrients; Phytoplankton. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-533.pdf |
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| Azandegbe, Afi; Gamier, Matthieu; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Vibrio aestuarianus is frequently found in coastal areas and can infect and induce mortalities in the pacific oyster Crassostrea gigas. However, nothing is known about its distribution and seasonality in the estuarine environment, especially where oyster farming is practiced. Its occurrence was investigated in sediment and oyster haemolymph at 2 oyster farms in Brittany (France) over 2 yr during 2 periods, from June to September 2007 and from February to June 2008. Total heterotrophic bacteria (HB) were cultured on marine agar while total Vibrio spp. and V. aestuarianus were selectively numerated using thiosulfate citrate bile salts sucrose agar (TCBS agar) and the species-specific hybridisation method, respectively. PCR was performed to detect V.... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; Crassostrea gigas Sediment; Seasonal abundance; Colony-blot. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00017/12813/9756.pdf |
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| Savoye, N; Aminot, Alain; Treguer, Paul; Fontugne, M; Naulet, N; Kerouel, Roger. |
| Two cruises (April and June 1997) were carried out in the Bay of Seine, a nitrate- and ammonium-enriched ecosystem of Western Europe, to identify the major mechanisms that control delta(15)N and VC in spring particulate organic matter (POM). Particulate organic nitrogen (PON) delta(15)N ranged between 0.8 and 5.2parts per thousand in April and between 2.2 and 6.2parts per thousand in June, while particulate organic carbon (POC) delta(13)C ranged between -24.3 and -19.7parts per thousand, and between -20.0 and -16.2parts per thousand during the same periods. During spring 1997, POM was highly dominated by autochthonous phytoplankton. It is shown that the variation of PON delta(15)N is due to both nitrate mixing between river and marine waters and... |
| Tipo: Text |
Palavras-chave: C and N stable isotopes; Phytoplankton; Coastal ecosystem; Nitrate utilization; Bay of Seine. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10645/7593.pdf |
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| Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor... |
| Tipo: Text |
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| The paper reviews the methods described in the literature for the determination of total dissolved free primary amines (TDFPA) by fluorescence. A wide set of reaction conditions can be found, but they rely on few experiments for their validation. Among fluorogenic compounds, o-plithaldialdehyde (OPA) is more sensitive than fluorescamine and was thus examined here. However, the use of mercaptoethanol (ME) in the reaction (as ail additional derivatization compound) is able to generate unreliable results, in particular when standardization relies on glycine. We suggest replacing ME with 3-mercaptopropionic acid (MPA) which induces more stable and comparable fluorescence among amine Compounds. A systematic study was therefore undertaken to define reagent... |
| Tipo: Text |
Palavras-chave: Fluorescence; Determination; Seawater; Total dissolved free primary amines. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2274.pdf |
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| Aminot, Alain; Kerouel, Roger; Le Guellec, Anne-marie; Bodennec, Guy; Quemeneur, Michelle; Marty, Yanic. |
| Ce travail est effectué dans le cadre du programme général concernant l'étude des rejets urbains en mer, sous la responsabilité de Jean-François GUILLAUD. Il constitue, dans ce programme, le premier volet de l'étude des paramètres entrant dans la chimie des cycles naturels, par la recherche d'une définition aussi précise que possible de la composition des effluents urbains brut et épuré et de leur évolution journalière. |
| Tipo: Text |
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| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00082/19295/16890.pdf |
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| Daniel, Anne; Kerouel, Roger; Aminot, Alain. |
| Following previous work, the production of reference material for nutrients in seawater, using pasteurization as a preservation method, was carried out seven times between 2006 and 2010 in the framework of inter-laboratory exercises. The preparation of samples from natural seawater allowed to become depleted in nutrients then spiked, bottled and pasteurized, is described. Five main nutrients are involved in this study: ammonium, nitrite, nitrate, phosphate and silicate. Bottles are in glass for the ammonium samples and in plastic for the other nutrients. Pasteurization was performed at 80 ± 3 °C for 2 h. Samples were controlled for homogeneity and stability at 3–5 month interval, before and after the period allocated for each exercise and a third time... |
| Tipo: Text |
Palavras-chave: Pasteurization; Nutrients; Seawater; Inter-laboratory exercises. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00058/16905/15066.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| A segmented flow automated method with on-line photo-oxidation for the determination of dissolved organic phosphorus + soluble reactive phosphorus (DOP + SRP) in seawater and fresh water is described here. A low-power lamp was used for a compact, easy-to-handle and low-ozone-producing manifold. The influence of seawater matrix components was studied in detail using natural seawater and salt solutions spiked with DOP model compounds. Bromide was found to be the most inhibitory species in seawater. The work shows that most salt solutions referred to as artificial seawater are not satisfactory model matrices to test the actual seawater matrix effect. Since DOP recovered in undiluted seawater samples was about half that obtained in fresh water samples, the... |
| Tipo: Text |
Palavras-chave: Measurement; Fresh water; Seawater; Total dissolved phosphorus; Dissolved organic phosphorus. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1678.pdf |
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| Aminot, Alain; Kerouel, Roger; Birot, Dominique. |
| A version of the orthophthaldialdehyde-fluorescence ammonium determination for flow injection analysis (FIA) is presented here, with a view to its use for in situ, low-power consumption systems, Thus, the reaction temperature was limited to 30 degreesC and FIA was used in stop-Bow mode (3 min stop). The calibration is linear up to 50 mu mol l(-1), but concentrations up to 100 mu mol l(-1) can be measured. Repeatability is around 1% in the range of 0.5-4 mu mol l(-1) and the detection limit is about 0.03 mu mol l(-1) Over the salinity range of 5-35 (seawater practical salinity scale) the salt effect is almost negligible (within +/- 2%); and below salinity of 5 it increases to a maximum of -9% in fresh water compared to seawater. Hydrogen carbonate,... |
| Tipo: Text |
Palavras-chave: In situ; Fluorometry; Flow injection analysis; Determination; Ammonium. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1722.pdf |
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| Lunven, Michel; Guillaud, Jean-francois; Crassous, Marie Pierre; Youenou, Agnes; Gohin, Francis; Huret, Martin; Danielou, Marie-madeleine; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| Inscrite dans le cadre du Grand Défi Golfe de Gascogne, la campagne VILOIR a été réalisée du 19 au 26 Juin 2003 à bord du Côtes de la Manche avec pour objectif l’étude en période estivale des structures hydrologiques et phytoplanctoniques des panaches de la Loire et de la Vilaine. Elle fait suite, sur la même thématique, à la campagne hivernale NUTRIGAS (2001) et à la campagne printanière GASPROD (2002). |
| Tipo: Text |
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxines; Bretagne; Pays de Loire. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00144/25494/23648.pdf |
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| Aminot, Alain; Guillaud, Jean-francois; Kerouel, Roger. |
| The data of hydrology, nutrients and chlorophyll obtained in the Bay of Seine over the period 1978-1994, from 14 océanographie cruises, are synthetised and illustrated by an atlas. The Bay is a typical example of a coastal area influenced by a large river. In winter, the nutrient input is drained off into the eastern Channel. In spring, nutrients are consumed intensively. Silicate is the first that drops to limiting levels. The spring bloom generally begins in the centre-east of the Bay. Chlorophyll a can reach up to 40-70 µg/l during the year, values typical of eutrophic coastal areas. Despite the regular increase of nitrogen inputs, the biomass (as chlorophyll) has not significantly changed over a fifteen year period. |
| Tipo: Text |
Palavras-chave: Chlorophyll; Nutrients; Hydrology; Bay of Seine; Chlorophylle; Nutriments; Hydrologie; Baie de Seine. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/rapport-1428.pdf |
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| Coverly, Stephen; Kerouel, Roger; Aminot, Alain. |
| Modern instruments together with the use of standard reference materials have improved the accuracy and long-term reproducibility of the analysis of nutrients (ammonium, nitrate, nitrite, phosphate and silicate) in sea water using segmented-flow analysis, so that errors arising from matrix effects become more significant. Colorimetric detectors with bubble-through flowcells have become widely used for seawater analysis in recent years and their associated matrix effects are described. A re-examination of all categories of matrix effects, whose main origin is salinity, was thus undertaken to assess how much they are liable to alter the data. Interferences were classified into four types, each of which was examined in order to show its influence on the... |
| Tipo: Text |
Palavras-chave: Nutrient; Determination; Seawater; Estuarine water; Segmented-flow analysis; Matrix effects. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00057/16843/14530.pdf |
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| Sarradin, Pierre-marie; Caprais, Jean-claude; Riso, Ricardo; Kerouel, Roger; Aminot, Alain. |
| Water samples were collected around the communities of a hydrothermal mussel, Bathymodiolus sp., in the Lucky Strike (1700 m depth) and Menez Gwen (850 m depth) areas, Mid Atlantic Ridge, and analysed for chemical constituents. The environment surrounding the organisms consists in sea water (88 to 100%) mixed with hydrothermal fluid with pH between 6.2 and 8, Sigma S (H2S + HS-) concentrations from 0 to 62 mu mol l(-1). High dissolved organic carbon (DOC) concentrations suggest a highly productive ecosystem. Production of ammonium and DOG, consumption of nitrate and sulfide in the vicinity of the organisms are among the environmental changes found in relation with local biological activity. Concentrations of Cu and Pb were high, implying that the organisms... |
| Tipo: Text |
Palavras-chave: Environment; Sea water; Hydrothermal vents; Mussels. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00147/25847/23968.pdf |
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| Andrieux, Francoise; Azandegbe, Afi; Caradec, Florian; Philippon, Xavier; Kerouel, Roger; Youenou, Agnes; Nicolas, Jean-louis. |
| This study aims to compare the impact of oyster cultures on diagenetic processes and the phosphorus cycle in the sediments of the Aber Benoît and the Rivière d’Auray, estuary of Brittany, France. Our results showed clear evidence of the seasonal impact of oyster cultures on sediment characteristics (grain size, organic matter parameters), and the phosphorus cycle, especially in the Aber Benoît. At this site, seasonal variations of sulfide and Fe concentrations in pore waters, as well as Fe-P concentrations in the solid-phase highlighted a shift from a system governed by iron reduction (Reference) to a system governed by sulphate reduction (Beneath Oyster). This could be partly explained by the increase in labile organic matter (ie, biodeposits) beneath... |
| Tipo: Text |
Palavras-chave: Sediment; Phosphorus; Sulfide; Dissolved Fe/P ratios; Labile organic matter; Oyster cultures. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00209/32003/30441.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| Dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) measured in deep profiles in the N-E Atlantic and in the N-W Mediterranean in the period 1984-2002 are described. After accurate validation, they show close agreement with those previously published. Classic profiles were obtained, with concentrations decreasing in deep waters. In the Mediterranean and in the Atlantic comparable concentrations were found in the 1500-2000 m waters, 44-46 mumol 1(-1) DOC, 2.6-2.8 mumol 1(-1) DON and 0.02-0.03 mumol 1-1 DOP. In the surface layers, DOC concentrations were higher, but DON and DOP concentrations lower, in the Mediterranean than in the Atlantic, leading to higher element ratios in the Mediterranean. In autumn,... |
| Tipo: Text |
Palavras-chave: N W Mediterranean; N E Atlantic; Mineralization; Non refractory; Refractory; Dissolved organic phosphorus; Dissolved organic nitrogen; Dissolved organic carbon. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-472.pdf |
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| Aminot, Alain; Kerouel, Roger; Joanny, Michel; Le Guellec, Anne-marie. |
| Les éléments nutritifs (N-NH4 +, N-N02-, N-NO3, P-PO4 3- et Si-Si(OH) 4) et la matière organique dissoute (COD, NOD, POD, urée, amines primaires libres) mesures en septembre 1984 en Méditerranee nord-occidentale sont interprétés en fonction de l'hydrologie. Les résurgences d'eaux subsuperficielles influencent plus les concentrations des éléments nutritifs que celles de la matière organique. La composition globale (en C, N et P) de la matière organique a pu être donnée : on note des différences entre les masses d'eau. |
| Tipo: Text |
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| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00082/19288/16883.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| La préparation de matériaux de référence pour des exercices d'intercomparaison pour les eaux de mer a été pratiquée à plusieurs reprises par notre laboratoire au cours des années passées, soit au niveau français (cas de la salinité pour le RNO) soit au niveau international (cas des nutriments). Ainsi, pour les nutriments, deux exercices du CIEM (Conseil International pour l'Exploration de la Mer) ont été préparés, lesquels ont été suivis du programme européen d'assurance qualité QUASIMEME comportant six exercices en trois ans. Nous avons également contribué à l'exercice concernant l'agrément des laboratoires type 8 « eaux marines » du Ministère de l'Environnement en 1998. Les résultats de ces exercices et les méthodes de préparation des matériaux de... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00018/12912/9868.pdf |
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| Daniel, Anne; Kerouel, Roger; Aminot, Alain; Youenou, Agnes. |
| Cet essai interlaboratoire (EIL) pour l’analyse des sels nutritifs en milieu marin a été organisé par le laboratoire DYNECO/PELAGOS de l’IFREMER le 14 février 2006. Il a été proposé en septembre 2005 aux Laboratoires Environnement Ressources (LER) de l’IFREMER, aux sous-traitants ou collaborateurs des LER, aux laboratoires effectuant des analyses dans le cadre du RNO-hydrologie, aux laboratoires du CNRS participant à SOMLIT (Service d’Observation du Milieu LITtoral) et aux laboratoires de l’IRD. Les 26 laboratoires qui ont participé à cet essai sont listés en Annexe 1. Aucune consigne n’a été donnée sur le choix de la technique analytique : chaque laboratoire a utilisé sa méthode de routine. |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00020/13144/10186.pdf |
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| Raimonet, Melanie; Ragueneau, Olivier; Andrieux Loyer, Francoise; Philippon, Xavier; Kerouel, Roger; Le Goff, Manon; Memery, Laurent. |
| The high heterogeneity of silica cycling in coastal margins and the lack of silica data (compared to nitrogen and phosphorus) prevent the estimation of global silica retention in estuaries. In this study, the spatial and temporal variability of porewater silicic acid (Si(OH)4) profiles e that integrate benthic transport and reaction processes e was investigated at different spatial (metre, longitudinal and crosssection, intra-estuary) and temporal (tidal, seasonal) scales in two macrotidal estuaries, very close geographically but essentially differing in their shape. Studying the spatial and temporal variability of Si(OH)4 concentrations in porewaters provided evidence for the importance of transport processes, e.g. bio-irrigation, tidal pumping,... |
| Tipo: Text |
Palavras-chave: Heterogeneity; Season; Silicate; Sediment; Land-sea interface; Upscaling. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00124/23529/22370.pdf |
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| Registros recuperados: 31 | |
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