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| Registros recuperados: 238 | |
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| Fichaut, Michele; Garcia, Maria-jesus; Giorgetti, Alessandra; Iona, Athanasia; Kuznetsov, Alexander; Rixen, Michel; Medar Group,. |
| A comprehensive database of temperature, salinity and bio-chemical parameters in the Mediterranean and Black Sea has been constructed through comprehensive co-operation between the bordering countries. Statistical climatologies have been computed with all assembled and quality controlled data. The database, designed to initiate and validate prediction models, also represents a system to quality-check new incoming data produced by ocean observing systems. |
| Tipo: Text |
Palavras-chave: Database; Temperature; Salinity; Nutrients; Climatology; Quality control. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00351/46177/45876.pdf |
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| Van Langenhove, Leandro; Depaepe, Thomas; Vicca, Sara; Van Den Berge, Joke; Stahl, Clement; Courtois, Elodie; Weedon, James; Urbina, Ifigenia; Grau, Oriol; Asensio, Dolores; Peñuelas, Josep; Boeckx, Pascal; Richter, Andreas; Van Der Straeten, Dominique; Janssens, Ivan A.. |
| Background and aims Biological fixation of atmospheric nitrogen (N2) is the main pathway for introducing N into unmanaged ecosystems. While recent estimates suggest that free-living N fixation (FLNF) accounts for the majority of N fixed in mature tropical forests, the controls governing this process are not completely understood. The aim of this study was to quantify FLNF rates and determine its drivers in two tropical pristine forests of French Guiana. Methods We used the acetylene reduction assay to measure FLNF rates at two sites, in two seasons and along three topographical positions, and used regression analyses to identify which edaphic explanatory variables, including carbon (C), nitrogen (N), phosphorus (P) and molybdenum (Mo) content, pH, water... |
| Tipo: Text |
Palavras-chave: Free-living nitrogen fixation; Tropical forest; French Guiana; Nutrients; Phosphorus; Molybdenum. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59901/63083.pdf |
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| Ben Othman, Hiba; Pringault, Olivier; Louati, Hela; Hlaili, Asma Sakka; Leboulanger, Christophe. |
| Effects of sediment-released contaminants and nitrogen were assessed on phytoplankton communities sampled from Thau lagoon (France, Mediterranean Sea) and one close offshore marine station. Phytoplankton was exposed to sediment elutriate (seawater containing a mix of metals, organic chemicals, and nutrients) or to ammonium enrichment for four days using immersed microcosms exposed to natural conditions of light and temperature. Functional (production - respiration balance) and structural (taxonomy and cell densities) responses of the phytoplankton community were assessed. In the lagoon, both treatments stimulated phytoplankton growth, compare to controls. Conversely in the offshore station, the phytoplankton growth was stimulated only with the sediment... |
| Tipo: Text |
Palavras-chave: Sediment resuspension; Mediterranean lagoon; Contaminants; Nutrients; Phytoplankton community. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00352/46364/46317.pdf |
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| Henley, Sian F.; Cavan, Emma L.; Fawcett, Sarah E.; Kerr, Rodrigo; Monteiro, Thiago; Sherrell, Robert M.; Bowie, Andrew R.; Boyd, Philip W.; Barnes, David K. A.; Schloss, Irene R.; Marshall, Tanya; Flynn, Raquel; Smith, Shantelle. |
| The Southern Ocean plays a critical role in regulating global climate as a major sink for atmospheric carbon dioxide (CO2), and in global ocean biogeochemistry by supplying nutrients to the global thermocline, thereby influencing global primary production and carbon export. Biogeochemical processes within the Southern Ocean regulate regional primary production and biological carbon uptake, primarily through iron supply, and support ecosystem functioning over a range of spatial and temporal scales. Here, we assimilate existing knowledge and present new data to examine the biogeochemical cycles of iron, carbon and major nutrients, their key drivers and their responses to, and roles in, contemporary climate and environmental change. Projected increases in... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Biogeochemistry; Primary production; Iron; Nutrients; Carbon; Ecosystem; Ocean acidification. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78831/81113.pdf |
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| Legovic, T; Justic, D. |
| Eutrophication of the northern Adriatic Sea was investigated using data on dissolved oxygen (DO) from 1911 to 1982. Beginning in the period 1955-1965, DO concentrations increased in the surface layer and decreased close to the bottom in all seasons except winter. These changes are attributed to an increase of the anthropogenic nutrient inflow. The occurrence of hypoxia near the bottom and its disappearance were investigated using the vertical distribution of DO on the transect from the Po delta to Rovinj during 1973. Horizontal distributions of DO close to the surface and near the bottom show prominent gradients from the Po delta towards the middle of the northern Adriatic Sea. Application of a simple box model indicates that phytoplankton blooms which... |
| Tipo: Text |
Palavras-chave: Hypoxia; Phytoplankton blooms; Nutrients; Eutrophication; Adriatic Sea. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20451/18123.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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| 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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| 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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| Merceron, Michel; Antoine, Virginie; Auby, Isabelle; Morand, P. |
| Ulva spp., the algae most responsible for green tides in Brittany (France), are found on the foreshore and in the most beachward wave area (MBWA) of many bays during green tide phenomena. These algae have recently been seen drifting at greater depths (reaching -20 m). In view of the significant quantities of algae found at these depths, and the less favorable conditions for algal growth than in the intertidal zone, we attempted to determine if they could grow there. For that, during their maximum growth period (from May to July), algae were picked up at three stations located on the foreshore, in the MBWA and in the subtidal (deep) zones of the Bay of Douarnenez, and their nitrogen, carbon and chlorophyll a+b contents were determined, and their... |
| Tipo: Text |
Palavras-chave: Nutrients; Irradiance; Photosynthesis; Ulva sp.; Algal blooms; Eutrophication. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3527.pdf |
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| Fiala, M; Delille, B; Dubreuil, C; Kopczynska, E; Leblanc, K; Morvan, J; Queguiner, B; Blain, S; Cailliau, C; Conan, P; Corvaisier, R; Denis, M; Frankignoulle, M; Oriol, L; Roy, S. |
| A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost convergence area of the Antarctic Circumpolar Current (ACC) and the Agulhas Return Current (ARC). Distribution of biogeochemical parameters was strongly linked to the merged Subtropical (STF) and Subantarctic (SAF) Fronts which mark the border between the cold and less saline subantarctic waters and the warm and more saline subtropical waters. This survey took place during a post-bloom period. Chlorophyll a concentrations were low throughout the study area ranging from 0.2 mug l(-1) in the Polar Frontal Zone (PFZ) to 0.4 mug l(-1) in the Subtropical Zone (STZ).... |
| Tipo: Text |
Palavras-chave: Frontal zones; Nutrients; Biogenic silica; Chlorophyll a; PCO(2); Phytoplankton; Bacteria. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33557/31968.pdf |
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| Guesdon, Stephane; Stachowski-haberkorn, Sabine; Lambert, Christophe; Beker, Beatriz; Brach-papa, Christophe; Auger, Dominique; Bechemin, Christian. |
| This study aimed to describe seasonal variations of phytoplankton abundances in relation to the physical and chemical (nutrients and metals) environment under the influence of freshwater input in the Charente river estuary (Marennes-Oléron bay, France) over three years, from 2011 to 2014. Phytoplankton abundances were determined using microscopy and flow cytometry. Considering high frequency temperature and salinity data, breakpoints in each series led to the identification of two local hydroclimatic periods: the first (2011 and early 2012) being warmer and higher in salinity than the second (from spring 2012 to the beginning of 2014). A multiblock PLS analysis highlighted the significant contribution of the physical environment (temperature, salinity and... |
| Tipo: Text |
Palavras-chave: Hydroclimate; Estuary; Phytoplankton; Size composition; Nutrients; Trace metals. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00349/46005/45674.pdf |
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| Agusti, Susana; Martinez-ayala, Juan; Regaudie-de-gioux, Aurore; Duarte, Carlos M.. |
| Increased oligotrophication is expected for oligotrophic areas as a consequence of ocean warming, which reduces diffusive vertical nutrient supply due to strengthened stratification. Evidence of ocean oligotrophication has been, thus far, reported for the open ocean. Here we reported oligotrophication and associated changes in plankton community metabolism with warming in a pristine, oligotrophic Mediterranean coastal area (Cap Salines, Mallorca Island, Spain) during a 10 years time series. As a temperate area, there were seasonal patterns associated to changes in the broad temperature range (12.0.28.4.C), with a primary phytoplankton bloom in late winter and a secondary one in the fall. Community respiration (R) rates peaked during summers and showed... |
| Tipo: Text |
Palavras-chave: Oligotrophiocation; Mediterranean sea; Respiration; Net community production; Nutrients; Gross primary production; Warming; Chlorophyll. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00419/53091/54048.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: 238 | |
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