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Registros recuperados: 48 | |
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Le Gland, Guillaume. |
Since 2010, planktonic algae Alexandrium minutum, cause of the PSP (Paralytic Shellfish Poisoning) syndrome, has been proliferating in early summer in the bay of Daoulas, within the roadstead of Brest. During this internship, a model has been designed in order to derive these blooms from physical parameters (temperature, irradiance, nutrient supply, dilution rate …). In the model, A.minutum competes with 50 other plankton species with randomly attributed optimal temperature and nutrient uptake abilities. It turns out to reproduce well the bloom of 2012, with a correct date of maximum concentration and a relevant order of magnitude. It reproduces the order of magnitude of 2013 concentrations, but the bloom then is too spread in time around the maximum.... |
Tipo: Text |
Palavras-chave: Alexandrium minutum; Phytoplancton; Efflorescence (bloom); Nutriments; Lumière; Température; Dilution; Absorption (uptake); Quota cellulaire; Croissance; Compétition; Modèle; Rade de Brest. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00209/32004/30442.pdf |
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Cantoni, C; Cozzi, S; Pecchiar, I; Cabrini, M; Mozeti, P; Catalano, G; Umani, Sf. |
Primary production (PP) and, nitrate (QNO(3)) and ammonium (QNH(4)) uptakes were measured together with other environmental parameters from October 1999 to February 2001 in the Gulf of Trieste (N Adriatic Sea). Their trends showed a high variability because of the combined effects of meteorological conditions, water circulation and river discharges. PP ranged from 0.2 to 1.5.9 mumol C dm(-3) d(-1), whereas QNO(3) varied from 0.8 to 442 nmol N dm(-3) d(-1), showing a trend similar to that of carbon basically ascribable to the autotrophic activity. QNH(4) ranged from 20 to 1308 nmol N dm-3 d-' and it reached the highest values during the declining phases of phytoplankton blooms, indicating that bacterial community can also be involved in its uptake.... |
Tipo: Text |
Palavras-chave: Production primaire; Production nouvelle; Nutriments; Temps de renouvellement; Apports de rivières; Primary production; New production; Nutrients turnover time; Riverine inputs. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00321/43248/42979.pdf |
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Mazouni, Nabila; Deslous-paoli, Jean-marc; Landrein, Sonia. |
The impact of suspended oyster culture (Crassostrea gigas, Thunberg) on oxygen and nutrient fluxes has been studied in situ, in a coastal lagoon (Thau, France), during a seasonal cycle. On the first plan of the multiple factorial correspondences analysis (MCA), seasons were well discriminated. The fluxes were maximum in summer and minimum in winter. However, this seasonal pattern was not only linked to the water temperature, as autumn and spring (similar temperatures of about 12 degrees C) were distinct in the second factorial plan (2.3). Oxygen uptake by the oyster cultures varied between 0 mu mol m(-2) h(-1) (January) and 11 823 +/- 377 mu mol m(-2) h(-1) (July). Ammonia and nitrate-nitrites were released into the water column respectively at a rate of... |
Tipo: Text |
Palavras-chave: Oxygen; Nutrients; Fluxes; Oyster culture; Oxygène; Nutriments; Flux; Elevage ostréicole. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-840.pdf |
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Menet-nedelec, Florence; Rabiller, Emilie; Courtay, Gaelle; Fontaine, Bruno; Francoise, Sylvaine; Jacqueline, Franck; Lesaulnier, Nadine; Louis, Fabienne; Maheux, Frank; Pierre-duplessix, Olivier; Schapira, Mathilde; Simon, Benjamin. |
Le Réseau Hydrologique Littoral Normand (RHLN) est financé par l’Agence de l’Eau Seine-Normandie, la Région Normandie et l’Ifremer. Il permet d’observer les niveaux d’eutrophisation et les phénomènes associés pour comprendre leur déclenchement et évolution, d’évaluer la qualité des eaux pour les Directives ou Conventions européennes (DCE, OSPAR, DCSMM), d’améliorer les connaissances via des projets de recherche, et permettre la validation des modèles. Ce rapport réalise la synthèse des résultats obtenus en 2016, seizième année depuis le début du suivi en Normandie, ainsi que pour la période 2011-2016 pour la préparation de l’Etat des Lieux 2019 de la Directive Cadre sur l’Eau. Le climat de l’année 2016 a été chaud surtout en été, et sec surtout en automne.... |
Tipo: Text |
Palavras-chave: Normandie; Baie de Seine; Écosystème côtier; RHLN; Réseau; Nutriments; Chlorophylle-a; Phytoplancton; Physico-chimie; Directive Cadre sur l’Eau; Eutrophisation; Évaluation DCE; Etat des Lieux DCE; DCSMM.. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00611/72339/71239.pdf |
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Hitier, Benoist; Olivesi, Rene; Rybarczyk, Hervé; Delesmont, Régis; Morel, Marc; Loquet, Nicolas. |
Nutrients levels of marine water along the North of France coastline are growing-up. They have a good chance to become a problem in the future. Since 1992, a network of three radial lines is sampled at regular interval to supervise on long term : 1. Parameters levels that show the environment quality (temperature, salinity, turbidity,total suspended matters, organic suspended matters, chlorophyll, phaeopigments, phytoplankton). 2. Nutrients concentrations ( ammonia, nitrite, nitrate, phosphate, silicate) that enrich the environment , and may be responsable of its deterioration. The report shows the results of the first three years survey. I t strikes a correlation between the tested parameters and takes stock of the present situation. |
Tipo: Text |
Palavras-chave: Suivi; Littoral; Nord-Pas de Calais; Picardie; Nutriments; Chlorophylle; Eutrophisation; Survey; Coastline; North of France; Picardie; Nutrients; Chlorophyll; Eutrophycation. |
Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00082/19277/16872.pdf |
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Menet-nedelec, Florence; Riou, Philippe; Rabiller, Emilie; Courtay, Gaelle; Fontaine, Bruno; Francoise, Sylvaine; Jacqueline, Franck; Lesaulnier, Nadine; Louis, Fabienne; Maheux, Frank; Pierre-duplessix, Olivier; Schapira, Mathilde; Simon, Benjamin; Dumas, Franck; Le Gendre, Romain. |
La stratégie d’échantillonnage optimisée du Réseau Hydrologique Littoral Normand (RHLN) a été approuvée en 2007 par ses partenaires, avec le triple objectif (1) d’observer les niveaux d’eutrophisation et les phénomènes associés pour comprendre leur déclenchement et évolution ; (2) d’évaluer la qualité des eaux selon les indicateurs réglementaires (DCE, OSPAR), et expertiser ces évaluations selon les connaissances actuelles du milieu ; et (3) d’améliorer et publier les connaissances via des projets de recherche, et permettre la validation des modèles. Ce rapport réalise la synthèse des résultats obtenus en 2015, treizième année depuis le début du suivi en Normandie. Le climat de l’année 2015 a été la troisième année la plus chaud en baie des Veys depuis 40... |
Tipo: Text |
Palavras-chave: Abondance; Baie de Seine; Biomasse chlorophyllienne; Bloom; DCE; Écosystème côtier; Éléments de qualité; Eutrophisation; Grille d’évaluation de l’eutrophisation; Hydrologie; Limitation potentielle; Normandie; Nutriments; Phytoplancton; Production primaire; Réseau hydrologique; RHLN; Stocks hivernaux. |
Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00426/53754/54647.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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Registros recuperados: 48 | |
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