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Registros recuperados: 139 | |
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Le Borgne, Y.; Marin, J.; Vergonzanne, G.. |
The hatchery-nursery from the Société Atlantique de Mariculture settled in Barfleur studied within the ECOTRON program set up by C.N.E.X.O. the characteristics of mass cultures for monospecific phytoplancton and of the rearing of oyster spat (Ostrea edulis. Crassostrea giqas) and clam spat (Venerupis semidecussata) . The maintenance features of the cultures in order to obtain cell densities around 1 million cell/ml. (or 50 g. of dry weight/m3) in containers up to 5000 liters have been established for the main species used in aquaculture (Isochrysis qalbana. Monochrysis lutheri, Tetraselmis suecica. Skeletonema costatum. Phaeodactylum tricornutum. Cyclotella nana, Chaetoceros calcitrans). The spat growth in nursery without providing any cultured food... |
Tipo: Text |
Palavras-chave: Écloserie; Nurserie; Phytoplancton; Bivalves; Naissain; Hatchery; Nursery; Phytoplancton; Bivalves; Spat. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00305/41658/40867.pdf |
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Jacques, G.; De Billy, G.. |
One approach to the problem of aquaculture consists in a simple acceleration of natural processes in extended areas of salt or brackish water. From this point of view, the authors have been interested in the effect of moderate fertilization on natural communities . A first series of experiments (8) was made in an external tank of 3000 liters. After fertilization, the development of flowering diatoms was obtained each time. The time of latency, the level of production reached, the composition of the final communities is to some extent variable, but bacterial development may be neglected. In contrast to earlier results, obtained in small volumes of water, these experiments have always led to simplified communities mostly dominated by the diatom... |
Tipo: Text |
Palavras-chave: Phytoplancton; Fertilisation; Chémostat.; Phytoplankton; Nutrient; Enrichment; Chemostat. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41688/40897.pdf |
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Nival, Paul; Malara, G.. |
Choosing the best conditions for the cultivation of plankton in tanks is a difficult deal, which is generally solved by means of subjective estimations. A better way of looking for these conditions is the use of a mathematical model. _ We have tried to built a model that accounts for the physical and biological characteristics of the tanks. The data concerning the physiological characteristics of the different group of organisms encountered are too scarce to allow all of them to be taken into account. The system studied here is composed of nutrients, phytoplankton, herbivorous copepods and rotifers to which benthic algae have been added. With the hypothesis of 3 elements (phyto - zooplankton - nutrients) it can be showed that when an equilibrium is... |
Tipo: Text |
Palavras-chave: Phytoplancton; Zooplancton; Culture; Modèle mathématique; Phytoplankton; Zooplankton; Culture; Mathematical model. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41673/40882.pdf |
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Divanach, P.; Sube, J.. |
Four marine phytoplanctonic cultures from natural inoculum of Nannodito sp. have been submitted to different fertilizers in identical light and temperature conditions. The composition of enrichments has been studied to introduce Nitrogen as comparative factor. One tank without nutrients and three enriched cultures, the first only with sodium nitrate, the second with "Conway medium" and the last in which nutrients were provided by convenient dilution of "foam", have been followed for physical, chemical, biological parameters during three months. Temperature, pH, dissolved oxygen, optical density, particulate matters, Organic Carbon, Nitrogen, Phos phorus, Calcium, Magnesium, Sodium, Potassium, metal traces and biological parameters were analysed... |
Tipo: Text |
Palavras-chave: Enrichissements; Recyclage; Écume; Phytoplancton; Déchets; Aquaculture; Enrichments; Recycling; Foam; Phytoplankton; Wastes; Aquaculture. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00305/41662/42780.pdf |
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Dufour, P.; Cremoux, Jl.; Slepoukha, M.. |
"In vitro" enrichment experiments on natural populations have been used to determine the nutrients controlling the potential biomass of phytoplancton in the Ebrié coastal lagoon. The limiting nutrients were generally nitrogen, phosphorus and carbon, in this order ; in three cases out of eleven, P and N act simultaneously ; in an extreme eutrophication case, N, P and C were all limiting. No effect was observed following addition of metals, vitamins or chelators. The limitations deduced from the enrichment experiments show a. good agreement with the elementary composition of the external medium ; in waters potentially limited by N alone, the dissolved inorganic nutrients have a N : P ratio lower than 25. The agreement is poorer when the sestonic N : P ratio... |
Tipo: Text |
Palavras-chave: Lagune; Estuaire; Zone tropicale; Phytoplancton; Biomasse; Eléments limitants; Tests biologiques; Composition chimique; Coastal lagoon; Estuary tropical zone; Phytoplankton; Biomass; Limiting nutrients; Bioassay; Chemlcal composition. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41689/40898.pdf |
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Lassus, Patrick; Maggi, Pierre; Proniewski, F.; Truquet, Philippe; Bardouil, Michele. |
Since 1987 Antifer oil tanker terminal (Normandy, France) was weIl known, as a preferential area for summer highest blooms of Dinophysis cf acuminata, a toxic dinoflagellate. Three oceanographic cruises were made in August 1989, before, in the course of and after the seasonal max. of this species. Results obtained from these cruises (hydrological parameters and phytoplankton) as weIl as from a daily survey at a reference station in Antifer harbour, corrobora te the prevailing role of coastal up flowing of Seine estuarine waters, pushed to the coast by a dominant S - SW wind, on intensity and duration of Dinophysis bloom. Such observations are in agreement with those of Summer 1987 at reference station. |
Tipo: Text |
Palavras-chave: Antifer; Dinophysis; Hydrologie; Phytoplancton; Antifer; Dinophysis; Hydrology; Phytoplankton. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00138/24946/23039.pdf |
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Baud, Jean-pierre; Haure, Joel; Marion, Anne; Robert, Jean-michel. |
Une étude hydrobiologique de quatre secteurs ostréicoles a été menée de mars à octobre 1987. Les eaux de la baie de Bourgneuf sont favorables à l'ostréiculture en raison de leurs teneurs en chlorophylle, sels nutritifs et seston. Les caractéristiques hydrobiologiques sont cependant différentes entre les secteur nord et sud, ces derniers présentant des conditions de milieu d'élevage plus stables. Le gradient de richesse phytoplanctonique de la zone intertidale proche du continent est orientée selon la veine principale du courant résiduel des masses d'eau, avec une décroissance marquée du nord au sud. Le secteur le plus nord (S3) est en période estivale une zone à forte probabilité de développement de dinoflagellés durant les marées de vives eaux. La zone du... |
Tipo: Text |
Palavras-chave: Hydrobiologie; Ostréiculture; Phytoplancton; Baie de Bourgneuf. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00048/15879/13301.pdf |
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Masson, Daniel; Ratiskol, Gilles; Burgeot, Thierry; Margat, Sylvie. |
Les secteurs conchylicoles atteints par les efflorescences phytoplanctoniques toxiques sont fermés par l'Administration dès que le taux de contamination devient dangereux pour la consommation humaine. Cette fermeture peut durer plusieurs mois empêchant les conchyliculteurs de commercialiser leurs produits, ce qui a des conséquences économiques parfois graves. Il n'existe jusqu'à présent aucune possibilité technique de décontaminer ces coquillages en grande quantité et dans des délais économiquement viables. L'étude entreprise visait à mettre au point une technique permettant aux professionnels de décontaminer des coquillages rapidement (quinze jours au moins) en milieu contrôlé (bassins). L'hypothèse testée était que des coquillages placés dans un milieu... |
Tipo: Text |
Palavras-chave: Coquillages; Décontamination; Toxicité; Phytoplancton. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00134/24499/22527.pdf |
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Le Dean, Loic; Gauthier, Franck. |
Nous avons réalisé cette étude dans le but de fournir aux agents d'IFREMER chargés de la surveillance des eaux littorales et en particulier de la flore phytoplanctonnique, un outil permettant d'identifier et de compter les cellules de Dinophysis de façon automatique. La visionique nous semblant être une discipline qui se prêtait à ce type de détection, nous avons réalisé une étude de faisabilité d'un système d'analyse d'il}1age appliqué à la reconnaissance et au comptage de Dinophysis. Le capteur utilisé est une caméra J.V.C Tri C.C.D transmettant trois images (rouge - verte - bleue) à un ordinateur compatible A.T.. Celui ci est équipé d'un ensemble de cartes MATROX de numérisation et traitement d'images et d'un coprossesseur arithmétique. Les applications... |
Tipo: Text |
Palavras-chave: Dinophysis; Phytoplancton; Visionique; Reconnaissance de forme; Segmentation; Binarisationcontours. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00136/24714/22768.pdf |
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Raillard, Olivier. |
La complication d'un modèle déterministe est une action qui ne peut être envisagée sans raisons impérieuses. En plus des mécanismes nouveaux qu'il importe de connaître précisément pour les formaliser correctement, l'introduction de nouveaux paramètres, dont la valeur exacte n'est jamais connue, accroit l'incertitude du modèle (Klepper et Scholten, 1988) et affecte ainsi sa robustesse (Swartzman et Kaluzny, 1987). A Marennes-Oléron, l'introduction d'un modèle de production primaire doit permettre d'aborder les problèmes suivants : Quelle est véritablement l'impact des débits de la Charente sur la production ostréicole? ou plus précisément : les nutriments d'origine charentaise contrôlent-ils la production phytoplanctonique du bassin et par voie de... |
Tipo: Text |
Palavras-chave: Modélisation; Croissance; Phytoplancton; Modèle biologique; Bassin de Marennes Oléron; Charente Maritime. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00102/21313/18932.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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Registros recuperados: 139 | |
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