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| Registros recuperados: 12 | |
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| Collos, Y; Vaquer, A; Laabir, M; Abadie, Eric; Laugier, Thierry; Pastoureaud, Annie; Souchu, Philippe. |
| A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original approach is used to assess the relative contribution of several nitrogen sources (nitrate, nitrite, ammonium, urea) to growth of A. catenella by comparing nitrogen uptake rates to nitrogen-based growth rates estimated from dilution experiments during four blooms over a 4-year period (2001-2004) in Thau lagoon. Nitrate and nitrite contributed 0.1-14% and 0.1-5%... |
| Tipo: Text |
Palavras-chave: Uptake kinetics; Ammonium; Urea; Growth; Nitrogen; HAB; Alexandrium catenella. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6454.pdf |
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| Alliot, E.; Pastoureaud, Annie; Trellu, J.. |
| The development of the digestive system of larvae of Dicentrarahus labrax has been studied. The changes in activities of digestive enzymes from hatching to 30 days have been investigated. 8 activities have been recorded : esterases, a-glucosidase, trypsin, chymotrypsin, leucinaminopeptidase, alkalin and acid phosphatase, using polyacrylamid gel electrophoresis. All the activities are very weak at hatching j the activities of trypsin, a-glucosidase, alkalin phosphatase increase between 0 and 5 days, decrease slowly and are quite stable from 15 to 30 days. The other activities increase steadily from 0 to 20 days. Relationships between the developmental process of the digestive system and changes in activities are investigated. |
| Tipo: Text |
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| Ano: 1977 |
URL: http://archimer.ifremer.fr/doc/00305/41619/40828.pdf |
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| Loret, Pascale; Le Gall, Solange; Dupuy, Christine; Blanchot, Jean; Pastoureaud, Annie; Delesalle, Bruno; Caisey, Xavier; Jonquieres, Gerard. |
| Pearl oysters are farmed in oligotrophic tropical atoll lagoons where planktonic communities are dominated by production from cyanobacteria smaller than 2 pm. Paradoxically, the pearl oyster Pinctada margaritifera only retains particles larger than 2 Pm. In this study, we assess the relative contribution of hetero/mixotrophic microbiota to the available planktonic resource. In Takapoto Atoll, picocyanobacteria are the dominant biomass (20 mug C l(-1)). The carbon biomass of ciliates and dinoflagellates ranges from 1 to 24 and 0.5 to 5 mug C l(-1) respectively, with a mean of 6 mug C l(-1) for ciliates and 2 mug C l(-1) for dinoflagellates. The possible retention by P. margaritifera on a natural protist suspension was investigated. Due to its high clearance... |
| Tipo: Text |
Palavras-chave: Trophic resource; Picoplankton; Pinctada margaritifera; Pearl oysters; Atoll lagoon; Protists. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-823.pdf |
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| Dupuy, Christine; Pastoureaud, Annie; Ryckaert, Mireille; Sauriau, Pierre-guy; Montanie, Hélène. |
| To assess the in situ impact of oysters Crassostrea gigas on planktonic protist and bacteria communities and the potential contribution of protozoa to their food resource intake, the abundance and the diversity of protists and bacteria were followed in 2 Atlantic coastal ponds, with and without oysters. The protist biomass in such ponds was high, with a maximum in spring of 982 mug C l(-1) and a minimum in winter of 179 pg C l(-1). Whatever the season, the presence of oysters (20 m(-2) corresponding to an average of 23 mg dry weight m(-2)) induced a significant decrease in >5 pm protist abundance. On the contrary, planktonic organisms <5 pm, such as Chlorophyta flagellates and bacteria, developed similarly in both ponds. It can be assumed that such... |
| Tipo: Text |
Palavras-chave: Trophic link; Bacteria; Protists; Microbial food web; Coastal pond; Food source; Oysters; Bivalve. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-822.pdf |
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| Pernet, Fabrice; Malet, Nathalie; Pastoureaud, Annie; Vaquer, Andre; Quere, Claudie; Dubroca, Laurent. |
| Carbon stable isotopes and fatty acids were measured in the suspended particulate organic matter (POM) of the Thau lagoon to study its qualitative temporal changes in relation to environmental factors and to identify the food sources of bivalves over a one-yr-cycle in relation to their growth. Reciprocally, the impact of shellfish farming on POM was also studied. Oysters and mussels were sampled and measured for biometry, stable isotopes and fatty acid composition. Water samples were collected at two sites, both inside and outside of the shellfish farming area, to determine concentrations in POM, chlorophyll a (Chl a) and stable isotopes. Carbon isotopes and fatty acids in bivalves reflected seasonal changes in food sources, which varied consistently with... |
| Tipo: Text |
Palavras-chave: Aquaculture; Bivalve; Competition; Feeding ecology; Growth; Trophic markers. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00075/18575/16177.pdf |
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| Pernet, Fabrice; Barret, Jean; Le Gall, Patrik; Malet, Nathalie; Pastoureaud, Annie; Munaron, Dominique; De Lorgeril, Julien; Bachere, Evelyne; Vaquer, Andre; Huvet, Arnaud; Corporeau, Charlotte; Normand, Julien; Boudry, Pierre; Moal, Jeanne; Quere, Claudie; Quilien, Virgile; Daniel, Jean-yves; Pepin, Jean-francois; Saulnier, Denis; Gonzalez, Jean-louis. |
| This study was conducted in the Mediterranean area during a mass mortality event of Pacific oyster Crassostrea gigas. The objectives of this work were to increase our understanding of the mass mortality phenomena in Pacific oysters, to identify risky cultivation practises and to propose mitigation strategies. In the first part of this work, we followed environmental parameters of the Thau lagoon in relation with mortality events. Then, we compared mortality and growth parameters of oysters as a function of their origins, their development stages and cultivation sites in relation with energetic, reproduction and pathogens. Finally, we conducted transfer experiments where oysters maintained free of mortality in open sea were transferred in the Thau lagoon... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11354/7927.pdf |
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| Collos, Yves; Bec, Beatrice; Jauzein, Cecile; Abadie, Eric; Laugier, Thierry; Lautier, Jacques; Pastoureaud, Annie; Souchu, Philippe; Vaquer, Andre. |
| Time series data have been examined in Thau lagoon (Southern France) from 1972 to 2006 for water temperature, salinity, nutrients and from 1987 to 2006 for phytoplankton. A first main trend identified is an increase in mean annual water temperature (1.5 degrees C over 33 years or 0.045 degrees C/year) that was not evenly distributed among seasons. The highest rate of increase was in the spring (+ 3.0 degrees C over 33 years), followed by summer (+ 2.0 degrees C and fall (+ 1.7 degrees C. In winter, no significant increase over the 33 year period could be found. A second clear trend is a large decrease in soluble reactive phosphorus (SRP) concentration over the same 33 year period (summer values decreased from 10 mu M to 1 mu M. while winter values... |
| Tipo: Text |
Palavras-chave: Skeletonema costatum; Alexandrium catenella; Picocyanobacteria; Oligotrophication; Long term variability; Thau lagoon. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6420.pdf |
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| Pastoureaud, Annie; Heral, Maurice; Prou, Jean; Razet, Daniel; Russu, Patricia. |
| Selective feeding in the adult oyster Crassostrea gigas was studied using natural particle assemblages in the estuarine environment of the Bassin de Marennes Oleron (France). Oysters were exposed to natural variations of suspended particulate matter by direct pumping of sea water from the bay during various tidal cycles. Experiments were conducted during the spring over both spring tides and neap tides, so as to obtain a maximum range of variation in seston characteristics, spring tide being characterized by very strong currents with high loads of resuspended materials (sediment, microphytobenthos and detritus). Particles were analysed for their chloropigment content by HPLC. The native pigments consisted exclusively of chlorophyll a and c, from both... |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/1995/publication-3085.pdf |
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| Sournia, Alain; Belin, Catherine; Billard, Chantal; Catherine, Martial; Erard-le Denn, Evelyne; Fresnel, Jacqueline; Lassus, Patrick; Pastoureaud, Annie; Soulard, René. |
| A dinoflagellate has produced green-water events along the Atlantic and English Channel coasts of France since 1982. It differs morphologically from each of the 12 taxa or so of green gymnodinoid dinoflagellates previously known. As some morphological details, as well as their variability, remain to be ascertained, this organism is illustrated and described here under the provisional designation of Gymnodinium "sp. 1982". The presence of chlorophyll b has been confirmed by HPLC analysis but it could not be ascertained whether true chloroplasts are present, or symbionts. The distribution is coastal and estuarine. The number and intensity of the outbreaks may be related to river runoff and to the amount of preceding rainfall. An encysted stage is described.... |
| Tipo: Text |
Palavras-chave: Bloom; Océan Atlantique; Manche; Morphologie; Chlorophylle b; Répartition géographique; Zone côtière; Milieu marin; Phytoplancton; Basse Normandie; France; Europe; Pyrrophycophyta; Algae; Thallophyta; Gymnodinium; BLOOMS; DINOFLAGELLATES; GREEN WATERS; GYMNODINIUM; PHYTOPLANKTON. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00133/24470/22487.pdf |
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| Laanaia, Nabil; Vaquer, Andre; Fiandrino, Annie; Genovesi, Benjamin; Pastoureaud, Annie; Cecchi, Philippe; Collos, Yves. |
| Since 1998, blooms of Alexandrium catenella/tamarense in the lagoon of Thau developed regularly each autumn, reaching a maximum of several millions cells per liter in 2004. By contrast, spring blooms occurred only twice (in 2000 and 2007). During these periods, sea surface temperatures (SST) and the wind patterns appear to impact the bloom occurrences much more than the apparent limiting resources such as inorganic nutrients. The analysis of SST and wind from April to June and September to November (from 2000 to 2007) indicates first that there has to be an initial wind stress in order to resuspend the cysts buried in the sediment. Blooms then occur after a period of weak winds (<4 m s(-1)) and of stable SST close to 20 degrees C (+/- 2 degrees C).... |
| Tipo: Text |
Palavras-chave: Alexandrium catenella/tamarense; Wind stress; SST; Thau lagoon; Mediterranean. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00157/26790/24936.pdf |
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| Registros recuperados: 12 | |
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