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Registros recuperados: 369 | |
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Lucas, Ronan; Courties, C.; Herbland, Alain; Goulletquer, Philippe; Marteau, Anne-laure; Lemonnier, Hugues. |
In tropical shrimp ponds, the increasing of feed input, concomitantly with the stocking shrimp biomass, induces an eutrophication of the ecosystem. Although difficult to maintain, its stability is required to guarantee the success of the culture. A 110-day period of phytoplankton and bacterioplankton stock and dynamics in an earthen pond (1.2 ha area, 1 m depth) was monitored using flow cytometry to provide baseline information on community characteristics and ecosystem instability. Seven autotrophic cell types were identified over the whole sampling period. Prokaryotic cells included Synechococcus sp., a group named UNK which presented an atypical new flow cytometric signature and picoeukaryotes (PEUK). Nanophytoplankton cells were represented by 4... |
Tipo: Text |
Palavras-chave: Tropical shrimp aquaculture; Ecosystem shift; Phytoplankton; Bacterioplankton; Vibrio; Flow cytometry. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00029/14068/11312.pdf |
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Martínez Canals, M.; Montalvo, J. F.; Lugioyo, G.M.; Loza, S.; Pérez, R.. |
Se realizó la evaluación de los posibles cambios ambientales debido a los impactos antrópicos que han ocurrido en los últimos años en este escenario y la redefinición de áreas que sufren afectaciones, teniendo en cuenta que cualquier alteración ambiental de este ecosistema, ya sea de origen natural o humano, puede tener una importante repercusión económica y social. A partir de los índices químicos y biológicos propuestos, las aguas del Golfo de Batabanó presentaron condiciones mesotróficas con tendencia a la eutrofización en cuatro áreas fundamentales. En los sedimentos del Golfo los valores de carbono orgánico (0.16-7.30 %) y sulfhídrico (12,19-22,90 μg/L) fueron característicos de fondos con altas concentraciones de materia orgánica. En el sector... |
Tipo: Journal Contribution |
Palavras-chave: Phytoplankton; Sediments; Heavy metals; Phytoplankton; Heavy metals; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_2223. |
Ano: 2006 |
URL: http://hdl.handle.net/1834/3340 |
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De La Broise, Denis; Stachowski-haberkorn, Sabine. |
Microcosms, each consisting of 2 L natural surface seawater maintained in 2.3-L glass bottles, were immersed at a depth of 6 metres. The renewal of ten percent of microcosm volumes was carried out every other day. Phytoplankton-containing seawater was used for renewal (previously filtered through 25-, 50- or 200-μm cut-off). Phytoplankton community pigment analysis (by HPLC) and flow cytometry analysis were performed. After 13 days, data exhibited phytoplankton characteristics in microcosms in the same range as that of the natural surrounding sea water over the same period. Furthermore, in these microcosms, a negative correlation was observed between the filtration cut-off used for renewal water, and the eukaryote cell count. Herbicides were tested as... |
Tipo: Text |
Palavras-chave: Phytoplankton; Microcosm; Herbicides; Dimethenamid; Bentazon. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19889/17548.pdf |
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Hamza, A.; Dammak-Zouari, H.; Bouain, A.. |
Il est connu que les ports soumis à un trafic maritime intense réceptionnent éventuellement les eaux de ballast des navires en provenance de diverses contrées océaniques. De part le monde, le transfert et l’invasion de plusieurs espèces nuisibles via le déversement des eaux de ballast et le fouling des coques des navires ont été amplement mis en cause ces derniers temps. Ces introductions peuvent causer de nombreux dégâts aux secteurs avoisinants et notamment dans les zones de production des coquillages surtout si les espèces introduites sont constituées de phytoplancton toxique. Au terme de 4 années de suivi de la qualité phytoplanctonique des milieux portuaires du golfe de Gabès, nous avons pu inventorier certaines espèces toxiques pour la plupart... |
Tipo: Journal Contribution |
Palavras-chave: Ballast; Ecology; Ecosystems; Eutrophication; Phytoplankton; Pollution monitoring; Toxicity. |
Ano: 2006 |
URL: http://hdl.handle.net/1834/4271 |
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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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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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Soudant, Dominique; Beliaeff, Benoit; Thomas, G. |
Classical regression analysis can be used to model time series. However, the assumption that model parameters are constant over time is not necessarily adapted to the data. In phytoplankton ecology, the relevance of time-varying parameter values has been shown using a dynamic linear regression model (DLRM). DLRMs, belonging to the class of Bayesian dynamic models, assume the existence of a non-observable time series of model parameters, which are estimated on-line, i.e. after each observation. The aim of this paper was to show how DLRM results could be used to explain variation of a time series of phytoplankton abundance. We applied DLRM to daily concentrations of Dinophysis cf. acuminata, determined in Antifer harbour (French coast of the English... |
Tipo: Text |
Palavras-chave: Phytoplankton; Dinophysis; Time series; Regression; Dynamic; Bayesian. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44784/44490.pdf |
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Lavaud, Romain; Flye-sainte-marie, Jonathan; Jean, Fred; Emmery, Antoine; Strand, Oivind; Kooijman, Sebastiaan A. L. M.. |
We developed a full life-cycle bioenergetic model for the great scallop P. maximusrelying on the concepts of the Dynamic Energy Budget (DEB) theory. The covariation method was implemented to estimate the parameters of a standard DEB model. Such models are able to predict various metabolic processes from a food availability marker and temperature in the environment. However, suspension-feeders are likely to feed on various trophic sources, from microalgae cells to detritus. They are also able to sort and select food particles very efficiently, depending on their size, energetic value or quality. The present model includes a mechanistic description of the feeding processes, based on Kooijman’s Synthesizing Unit principle which allow to deal with several food... |
Tipo: Text |
Palavras-chave: Pecten maximus; DEB theory; Synthesizing Units; Phytoplankton; Feeding process; Bay of Brest. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00162/27316/28458.pdf |
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Registros recuperados: 369 | |
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