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| Registros recuperados: 30 | |
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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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| Cabecadas, L. |
| Biomass and phytoplankton photosynthetic response were studied in the lower Tagus estuary weekly, and related to environmental conditions in February, March and April 1994. The Photosynthesis-Irradiance ((P-I)-I-B) relation was studied based on the light-saturated photosynthesis rate (P(B)m) and the light-limited initial slope (a(B)). The nutrient concentrations observed were high enough to be considered as not limiting phytoplankton growth. Tagus estuary phytoplankton seems, to a certain extent, adapted to high turbid conditions, being able to utilize the low light levels more efficiently, which was translated by high values of a(B) [0.10-0.20 mg C (mg Chl a)(-1) h(-1) (W m(-2))(-1)]; however, light seems to limit phytoplankton production in the water... |
| Tipo: Text |
Palavras-chave: Production primaire; Phytoplancton; Estuaire; Biomasse; Turbidité; Primary production; Phytoplankton; Estuary; Biomass; Turbidity. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43621/43310.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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| Richard, Pierre; Blanchard, Gerard; Goulletquer, Philippe. |
| The trophic resources of cultivated mussel have! been characterized and their contribution to the food of these molluscs estimated in the Bay of Aiguillon (France) through the analysis of their natural C and N isotope composition. The contribution of terrestrial organic matter (δ(13)C = -27 to -34 %0) to mussel food resources is around 10% along the year, except in winter (15 10 30 %). A large seasonal variation is observed in the utilization of oceanic phytoplanktoll (δ(13)C = -19 to -21.5 %0) and of littoral benthic productions (microphytobenthos and phanerogame detritus,δ(13)C = -12.0 to -16.7 %0). Overall, the main food source of mussels is formed by benthic productions for molluscs grown on poles, in peculiar in the South of... |
| Tipo: Text |
Palavras-chave: Détritus; Production primaire; Isotope stable; Source trophique; Moule. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-2774.pdf |
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| Dussauze, Morgan. |
| Le modèle hydrodynamique/biogéochimique ECO-MARS 30 est appliqué à la Baie de Bourgneuf (mailles des 500 mètres) afin d'une part, de modéliser la production primaire et d'autre part, d'introduire le modèle de croissance de l'huître Crassostrea gigas (Bari lié et al, 1997). Le modèle n'étant muni ni d'un module de remise en suspension du sédiment, ni d'un module permettant de représenter le compartiment microphytobenthique, une approximation (forçage d'une climatologie pour la matière en suspension, utilisation d'un terme source dans la couche de fond pour la chlorophylle) a été effectuée afin de représenter de manière schématique le gradient Nord-Sud de turbidité, les rapides changements de turbidité qui sont mesurés au niveau des bancs ostréicoles au... |
| Tipo: Text |
Palavras-chave: Baie de Bourgneuf; Production primaire; Croissance de l'huître; Modèle mathématique. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00446/55746/57401.pdf |
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| Le Borgne, R; Rodier, M; Le Bouteiller, A; Murray, Jw. |
| Observations made during a "La Nina" situation (April-May 1996) in the equatorial Pacific upwelling, between 165 degrees E and 150 degrees W, show the classic deepening of hydrological isolines from east to west, resulting in zonal gradients for surface temperature and macronutrients. However, contrasting with such a gradient, no clear zonal variation could be seen for integrated planktonic biomasses and carbon fluxes, namely: chlorophyll a, bacterial abundances, particulate organic phosphorus, mesozooplankton ash free dry weight, primary production, and the sinking flux of particulate organic carbon (POC). Moreover, mean values of these parameters along the zonal equatorial transect, are not significantly different from those of a 7-day-long time series... |
| Tipo: Text |
Palavras-chave: Pacifique équatorial; Variabilité zonale; Plancton; Sédimentation de carbone; Production primaire; Equatorial Pacific; Zonal variations; Plankton; Carbon sinking flux; Primary production. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43629/43254.pdf |
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| Dussauze, Morgan. |
| Cette étude financée à 50% par l’Agence de l’Eau Loire/Bretagne avait pour but de modéliser la production primaire et l’oxygène dissous dans la zone Loire/Vilaine au moyen du modèle Ifremer ECO-MARS 3D. Après validation des résultats à l’aide de données in situ et satellitaires, elle a permis de déterminer la classification DCE des différentes masses d’eaux de la zone suivant les critères ‘biomasse phytoplanctonique’ et ‘oxygène dissous’. Elle a également donné pour la première fois une idée de l’étendue de la zone potentiellement sensible à l’hypoxie. Différents scénarios de réduction des apports azotés et phosphorés (-20%, -50% et +20%) ont été réalisés. En voici les principales conclusions : -les diatomées sont assez peu sensibles aux différentes... |
| Tipo: Text |
Palavras-chave: Zone Loire/Vilaine; Modélisation 3D; Production primaire; Oxygène dissous; Classement DCE. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00061/17207/14713.pdf |
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| Loquet, N; Rybarczyk, H; Elkaim, B. |
| The Bay of Somme is the second ranked estuarine system, after the Seine estuary, on the French coasts of the Eastern Channel. The nutrient retention and regeneration capacities of this estuary have been calculated from continental and coastal hydrological data and from estimation of the residence time. Measurements at the mouths of the main rivers over a one-year period (from October 1994 to November 1995) were used to construct a budget of continental inputs which showed that the smaller rivers could, at times, be important contributors. The annual budget shows continental inputs of nitrogen, phosphorus, silicon and suspended particulate matter of 9 000 t . y(-1), 380 t . y(-1), 5 400 t y(-1) and 67 800 t . y(-1). Estimation of coastal inputs to the... |
| Tipo: Text |
Palavras-chave: Manche; Baie de Somme; Flux de nutriments; Production primaire; English Channel; Bay of Somme; Nutrient fluxes; Primary production. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00325/43577/44045.pdf |
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| Videau, Christiane; Ryckaert, Mireille; L' Helguen, Stéphane. |
| Phytoplankton distribution and primary productivity were investigated in the Bay of Seine (eastern English Channel, France) in spring and early summer of 1992 and 1994. In 1992, the horizontal distribution of phytoplankton species was determined over the whole Bay of Seine. In 1994, species distribution and primary productivity were studied along the salinity gradient of the Seine plume and in the neighbouring marine waters. Phytoplankton distribution was characterised by the permanent diatom dominance from early spring to early summer. The spring bloom did not occur uniformly over the bay, but was initiated in the marine waters, in the middle of the bay and progressed towards the coast where it developed, in June, in the diluted waters of the Seine plume.... |
| Tipo: Text |
Palavras-chave: Baie de Seine; Production primaire; Phytoplancton; Bay of Seine; Primary productivity; Phytoplankton. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00333/44398/44057.pdf |
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| Hoch, Thierry. |
| This paper deals with a model of the pelagic ecosystem in the English Channel The model takes into account nitrogen biogeochemical cycle explicitly and indirectly phosphorus, silicon and carbon ones. The pelagic ecosystem is described precisely, on the one hand with the help of three phytoplanktonic compartments, and the other by considering the microbial food web. Primary production appears to be mainly controlled by stratification and turbidity, except in the Bay of Seine where high terrestrial nutrient inputs generate a sharp enrichment. Moreover, the model allows some general ecological conclusions to be drawn. From the simulation, it appears that inorganic nitrogen in the water column is mainly produced by an intense recycling. In accordance with in... |
| Tipo: Text |
Palavras-chave: Nitrogen fluxes; Primary production; Ecological model; English Channel; Flux d'azote; Production primaire; Modèle écologique; Manche. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-841.pdf |
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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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| Eaucea,; Prou, Jean. |
| L'objet de l'étude est de décrire les liens principaux entre l'hydrologie de la Charente et les constats qualitatifs dans le bassin de Marennes, ainsi que l'estimation des flux continentaux, sur la base des données des stations de Fontenelles et de Boyard entre 1977 et 2006. Du fait de l'influence de la marée, il n'est pas possible de mesurer les débits de la Charente dans sa partie aval. Ils ont donc été reconstitués à partir des stations de Saint-Savinien, du pont de Beillant, de Carillon, du Moulin de Chatre, de la Lijardière, de Jarnac, de Vindelle et de Foulpougne, en fonction de la disponibilité et de la fiabilité des données. Les mesures à Fontenelles et Boyard ont été réalisées de façon à disposer d'une gamme variée de situations par rapport au... |
| Tipo: Text |
Palavras-chave: Hydrologie; Flux continentaux; Cycle de marée; Nitrates; Phosphates; Production primaire; Marennes Oléron; Charente. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00083/19419/17030.pdf |
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| Registros recuperados: 30 | |
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