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| Registros recuperados: 22 | |
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| Christensen, Jp. |
| A diagenetic model of porewater O-2 was used to examine the relationship between organic carbon flux to the sediments and benthic oxygen demand (BOD). The model predicted that the organic carbon influx to sediments balances BOD as long as sediments are oxygenated. The critical rate occurs when O-2 at infinite depth disappears. With influxes exceeding the critical rate, the O-2 flux into the sediments via molecular diffusion can not consume all incoming organic matter, and anaerobic conditions result in BOD underestimating the carbon influx. Given that low rates of deep-sea BOD approximate the carbon influx below 9 g.C.m(-2).y(-1), a significant multilinear regression was found between published BOD, primary productivity (P-p, both in g.C.m(-2).y(-1))(,)... |
| Tipo: Text |
Palavras-chave: Fonds marins; Oxygène; Production primaire; Respiration; Sédiments; Deep-sea; Oxygen; Primary productivity; Respiration; Sediments. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00325/43578/44046.pdf |
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| Arzul, Genevieve. |
| Les études entreprises sur le thème "Eaux colorées" durant les années 1984-1985 ont montré des résultats divers : - les essais de cultures de Dinophysis acuminata et de Gyrodinium aureolum ont donné des résultats fragmentaires tout en permettant de dégager quelques points positifs, mais les essais de mise en culture n'ont pas encore abouti. - les études hydrologiques à long terme pour la surveillance d'apparition de Gyrodinium aureolum en Baie de Douarnenez, Dinophysis acuminata dans un bassin du Havre et en Baie de Vilaine sont en voie d'achèvement. Y sont adjointes les observations faites sur les échantillons prélevés à Plogoff et Ploumoguer en 1978-80. - l'extraction des toxines de Gyrodinium aureolum, la standardisation du test souris pour le DSP,... |
| Tipo: Text |
Palavras-chave: Eaux colorées; Dinophysis acuminata; Gyrodinium aureolum; Phyto-toxines; Sédiments. |
| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00139/25020/23125.pdf |
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| Marchand, Michel; Roucache, J. |
| In October 16, 1976, the tanker "Bohlen" was wrecked in the Mer d'Iroise, at about 35 miles of Brest, and lossed about 7 000 t of Boscan crude oil. The coast of Brittany was polluted by 3 000 t, and 4000 t were dispersed in the marine environment. In July 1977, 23 surface sediment samples were collected to look for the traces of oil spill in the sea bottom, 9 months after the shipwreck. Only one sediment was very iittle polluted by the Boscan crude oil. Elsewhere, two other kinds of oil pollution were observed in sorne sediment samples. Severa! quantitative and qualitative criteria were used to research sorne oil pollution in the marine sediments and to know the origin: hydrocarbon concentrations, ratios total organic extra ct 1 organic carbon,... |
| Tipo: Text |
Palavras-chave: Pollution; Hydrocarbures; Sédiments; « Bohlen »; Pollution; Hydrocarbons; Sediments; "Bohlen". |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00121/23206/21051.pdf |
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| Derrien, Annick. |
| Le rôle des sédiments dans la contamination du milieu marin en baie de l'Aiguillon est une des problématiques du laboratoire. Pendant quinze mois des dénombrements d'Escherichia coli dans des sédiments de la baie ont été effectués. Deux méthodes de numération ont été comparées: la technique NPP en tubes et la technique NPP en microplaque. En période printemps-été, la méthode NPP miniaturisée a conduit à des résultats sensiblement supérieurs à ceux obtenus par la méthode NPP en tubes. Cette différence pourrait s'expliquer par une fluorescence parasite du sédiment pendant cette période (éventuellement par du plancton; hypothèse non confirmée). Les concentrations en E.coli des sédiments sont variables au cours de l'année avec un niveau de contamination faible... |
| Tipo: Text |
Palavras-chave: Sédiments; Escherichia coli; Dénombrement. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00107/21811/19386.pdf |
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| Souchu, Philippe; Cochennec-laureau, Nathalie; Ratmaya, Widya; Retho, Michael; Andrieux, Francoise; Le Merrer, Yoann; Barille, Laurent; Barille, Anne-laure; Goubert, Evelyne; Plus, Martin; Laverman, Anniet. |
| Le projet DIETE a exploré les données hydrobiologiques (paramètres physico-chimiques, nutriments, phytoplancton) acquises depuis les années 80 dans les eaux côtières au large de la Loire et de la Vilaine, parallèlement à celles des deux fleuves. L’augmentation des concentrations de nitrates dans les eaux de la Loire, appuyée par les réserves sédimentaires de phosphates et de silicate ont entraîné de profonds bouleversements dans la dynamique du phytoplancton de la baie de Vilaine ces deux dernières décennies avec 1) une augmentation substantielle de la biomasse, 2) une modification importante de l’évolution saisonnière, 3) un changement dans les proportions entre diatomées et dinoflagellés au profit des diatomées. Ces résultats ouvrent tout un champ... |
| Tipo: Text |
Palavras-chave: Eutophisation; Azote; Phosphore; Silicium; Sédiments; Modélisation. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00425/53695/54593.pdf |
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| Gonzalez, Jean-louis; Boutier, Bernard; Chiffoleau, Jean-francois; Auger, Dominique; Noel, Joelle; Truquet, Isabelle. |
| The study of Cd and Hg distribution in the sediments, water and suspended matter of the Bay of Marennes-Oléron provided the opportunity to identify the factors governing the distribution of these two contaminants throughout the bay. On one hand, these elements are associated with the continental inputs from the Charente river which settle on arrivaI at the mouth of the estuary and in the eastern part of the bay. The Cd and Hg present in these deposits are associated with POC, as weIl as with Mn and Fe oxides and hydroxides. On the other hand, a portion of the dissolved inputs is recycled in the bay waters through phytoplankton activity. This mechanism contributes, particularly in the case of Cd, to increased particulate metal fluxes from the water column... |
| Tipo: Text |
Palavras-chave: Baie de Marennes-Oléron; Métaux lourds; Sédiments; MES; Activité phytoplanctonique; BAY OF MARENNES-OLERON; HEAVY METALS; SEDIMENTS; SUSPENDED MATTER; PHYTOPLANKTON ACTIVITY. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00085/19604/17242.pdf |
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| Clave, B; Masse, L; Carbonel, P; Tastet, Jp. |
| The La Perroche marsh is a small Holocene marsh on the south-western coast of the Oleron island (Bay of Biscay, France) presently occupied by a freshwater swamp and separated from the ocean by a continuous sand dune ridge. The study of its infill shows first basal conglomeratic deposits with calcareous pebbles on a Cenomanian rough substrate. The Holocene infill since 6000 years BP begins with a very fast sedimentation of sands. Then, the sedimentation becomes finer, with lagoonal to freshwater influences recorded by ostracods. The distribution of these deposits inside the marsh is asymmetric, with a thick sandy-gravely layer in the eastern part and a succession of sands, clays and organic layers in the western part. Communication with the sea is episodic,... |
| Tipo: Text |
Palavras-chave: Changements côtiers; Marais maritime; Holocène; Ostracodes; Sédiments; Coastal changes; Coastal salt marsh; Holocene; Ostracods; Sediments. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43349/42877.pdf |
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| Kervella, Youen. |
| Oyster farm structures represent artificial obstacles which can disturb tidal currents and wave propagation, and thus modify sediment transport patterns. Local deposition may result from these modifications, in proportions that may threaten the oyster farming. The impact of structures on hydrodynamics, waves and currents, is investigated at different spatial scales by means of in-situ measurements, experimental tests and numerical modeling. These different approaches show that in the near-field, tidal currents are modified in terms of intensity and direction but there is no significant impact on the waves. On the other hand, at the scale of the oyster farm, a significant reduction of the current velocities and a large wave height attenuation are recorded.... |
| Tipo: Text |
Palavras-chave: Tables à huîtres; Envasement; Courants; Vagues; Sédiments; Impact; Oyster tables; Silting up; Currents; Waves; Sediment; Impact. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12262/9043.pdf |
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| Bianchi, A; Calafat, A; De Wit, R; Garcin, J; Tholosan, O; Cacho, I; Canals, M; Fabres, J; Grout, H; Masque, P; Sanchez-cabeza, Ja; Sempere, R. |
| Microbiological and biogeochemical studies were carried out in sediments and near bottom waters in the upwelling area off the Malaga coast and in the Almeria-Oran frontal zone. In these nutrient-rich conditions, metabolic activity is potentially limited by oxygen availability through the sediment depth. In the surficial sediments of the frontal zone, however, oxygen penetrated to a depth of 4 cm, allowing oxic mineralisation processes to occur throughout the layer. In the surficial sediments of the upwelling area, oxygen penetration was limited to the top 2.5 cm, leading to anoxic conditions. Glutamate respiration and global oxygen uptake rates were clearly higher than in the frontal zone. In the superficial sediments of the frontal zone, bacteria were... |
| Tipo: Text |
Palavras-chave: Taux de minéralisation; Sédiments; Eaux profondes; Méditerranée occidentale; Bacteria; Mineralisation rate; Sediments; Deep-sea; Western Mediterranean. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00322/43298/43034.pdf |
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| Chiffoleau, Jean-francois; Truquet, Isabelle. |
| Des matières solides séchées sont minéralisées en bombe fermée par un mélange d'acide nitrique, d'acide chlorhydrique et d'acide fluorhydrique à environ 120 °C pendant 180 minutes. Cette attaque acide est totale et le minéralisat liquide obtenu est analysé pour sa teneur en métaux par absorption atomique avec ou sans flamme. C'est une méthode très sensible puisqu'elle permet de détecter dans des particules jusqu'à 0,35 % d'Al; 0,15 % de Fe, 0,1 mg/kg de Cd, 2 mg/kg de Co, 0,4 mg/kg de Cr, 2 mg/kg de Cu, 0,4 mg/kg de Mn, 2 mg/kg de Ni, 2 mg/kg de Pb, 0,1 mg/kg de Zn. La précision de cette méthode, sa reproductibilité ( de l'ordre de 7 % ) et sa facilité de mise en oeuvre en font une méthode de choix pour l'étude de faibles de quantité d'échantillons, comme... |
| Tipo: Text |
Palavras-chave: Analyse; Métaux-traces; Sédiments; Matières en suspension; Absorption atomique. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00140/25119/23228.pdf |
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| Ehrhold, Axel; Chevalier, Claire; Alix, Anne-sophie; Autret, Elodie; Caisey, Xavier; Drussel, Benjamin; Gaffet, Jean-dominique; Hamon, Dominique; Houlgatte, Eric; Pluquet, Fabrice; Biscara, Laurie; Choisnet, Justine; Bajjouk, Touria. |
| In 2000 Ifremer launched and coordinated the development of a monitoring strategy for the REBENT network (REseau BENThique) in order to assess the aftermath of the “Erika” oil spill which took place in December 1999. Its aim is to provide consistent baseline knowledge on coastal benthic habitats, as well as to develop a monitoring tool that detects changes at various spatial and temporal scales. Sector-based seabed habitat mapping in shallow water (< 50 m deep), is currently being conducted throughout Brittany's coastal waters using a combination of geoacoustic marine systems together with ground-truthing using biological grab sampling and seabed observations. Due to the extended area, the overlap of soft and rocky bottoms, and contrasting hydrological... |
| Tipo: Text |
Palavras-chave: Rebent; Trégor-Goëlo; Bréhat; Cartographie d’habitats; Sonar latéral; Macrofaune benthique; Peuplements; Crépidule; Maërl; Sédiments; Morphologie; Dynamique sédimentaire; Rebent; Trégor-Goëlo; Bréhat archipelago; Marine habitat mapping; Sidescan sonar; Benthic macrofauna; Communities; Crepidula bed; Maerl; Sediment; Morphology; Bedload transpor. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00280/39161/37724.pdf |
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| Registros recuperados: 22 | |
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