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| Lafon, Virginie; Marieu, Vincent; Butel, Rémi; Dehouck, Aurélie; Froidefond, Jean-marie; Trut, Gilles. |
| This study presents the first results of an ongoing research program that aims to derive thematic maps of the intertidal lagoon of Arcachon (SW Atlantic coast of France) from space imagery. At this stage, we present the results of the tests performed on Formosat-2 imagery. Several classification strategies have been tried with the aim to discriminate the sedimentary facies and the main species of the lagoon. The classes calculated by an optimized unsupervised clustering method, based on simulated annealing global minimization technique, were used to train a supervised classification algorithm. This approach allowed us to derive a bio-sedimentary map which overall accuracy is about 84%. Also, this method has the advantage of describing the fraction of... |
| Tipo: Text |
Palavras-chave: Télédétection; Cartographie; Littoral; Classification optimisée; Recuit simulé. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00254/36572/35110.pdf |
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| Binias, Cindy; Do, Van Tu; Jude-lemeilleur, Florence; Plus, Martin; Froidefond, Jean-marie; De Montaudouin, Xavier. |
| The aim of the present study was to identify environmental factors that could explain the distribution of different pathologies of commercially exploited intertidal bivalves in an Atlantic lagoon, Arcachon Bay. In particular, the role of the salinity gradient as a driver was explored. The Manila clam Ruditapes philippinarum experienced two severe pathologies, perkinsosis, which is due to a protozoan parasite, and brown muscle disease (BMD), the etiological agent of which remains unknown. Perkinsus olseni infection was very low in a small low-salinity area but, at the scale of the entire lagoon, was more influenced by organic matter content in the sediment and by emersion time. BMD prevalence was also 2.6 times higher in the higher organic content area but... |
| Tipo: Text |
Palavras-chave: Arcachon bay; Bivalves; Diseases; Distribution; Parasites. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00200/31083/31922.pdf |
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| Petitgas, Pierre; Masse, Jacques; Bourriau, Paul; Beillois, Pierre; Bergeron, Jean-pierre; Delmas, Daniel; Herbland, Alain; Koueta, Noussithe; Froidefond, Jean-marie; Santos, Maria. |
| The spatial pattern in hydro-plankton and fish distributions and their relationship were analysed based on the spring 2000 fisheries acoustic survey. The importance of this survey was that it was a multi-disciplinary platform which collected an extensive set of parameters in the hydro-plankton leading to a potentially finer description of hydro-plankton conditions and fish habitats. More than 50 variables were measured on a grid of stations, in four compartments of the ecosystem: hydrology, nutrients, primary producers and meso-zooplankton. First, a joint analysis of all hydro-plankton compartments was performed using multiple factor analysis (MFA). The method was used to estimate a compromise factorial space common to all compartments in which the... |
| Tipo: Text |
Palavras-chave: Fish environment relationship; Hydro plankton; Habitats; Multiple factor analysis; Spatial pattern. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3961.pdf |
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| Ouillon, Sylvain; Douillet, Pascal; Petrenko, Anne; Neveux, Jacques; Dupouy, Cecile; Froidefond, Jean-marie; Andrefouet, Serge; Munoz-caravaca, Alain. |
| Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the Cienfuegos Bay (Cuba), and sediment-rich waters in the Laucala Bay (Fiji). In this paper, optical algorithms for turbidity are presented per site based on 113 stations in New Caledonia, 24 stations in Cuba and 56 stations in Fiji. Empirical algorithms are tested at... |
| Tipo: Text |
Palavras-chave: Ocean color; Remote sensing; Sediment transport; Suspended matter; Turbidity; New Caledonia; Cuba; Fiji. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00203/31417/29808.pdf |
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