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Registros recuperados: 99 | |
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Artigas, Luis Felipe; Didry, Morgane; Barthelemy, Vanille; Bonato, Simon; Broutin, Mathias; Lizon, Fabrice; Lefebvre, Alain. |
The European Union Water Framework Directive (WFD) refers to phytoplankton as one of the biological quality elements that should be regularly monitored and evaluated thanks to three ecological indices: biomass, abundance and composition. The first two have already been defined, but the third one has not yet been proposed in the English Channel-Atlantic zone. The construction of a composition indice must consider the diversity of all the phytoplankton. As the microscopic counts concern only the micro-phytoplankton, it is necessary to use additional information which concerns the nano- and pico-phytoplankton, of great importance when estimating the phytoplankton diversity. These components of the phytoplankton can be measured by different complementary... |
Tipo: Text |
Palavras-chave: Manche Orientale; Groupes phytoplanctoniques; Cytométrie en Flux de type Scanning; Fluorimétrie spectrale; Analyses pigmentaires; Eastern English Channel; Phytoplankton groups; Scanning Flow Cytometry; Spectral fluorescence; Pigments analysis. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00361/47259/47224.pdf |
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Boulart, C; Flament, Pierre; Gentilhomme, V; Deboudt, K; Migon, C; Lizon, F; Schapira, M; Lefebvre, Alain. |
Wet atmospheric deposition of dissolved N, P and Si species is studied in well-mixed coastal ecosystem to evaluate its potential to stimulate photosynthetic activities in nutrient-depleted conditions. Our results show that, during spring, seawater is greatly depleted in major nutrients: Dissolved Inorganic Nitrogen (DIN), Dissolved Inorganic Phosphorus (DIP) and Silicic acid (Si), in parallel with an increase of phytoplanktonic biomass. In spring (March-May) and summer (June-September), wet atmospheric deposition is the predominant source (> 60%, relative to riverine contribution) for nitrates and ammonium inputs to this N-limited coastal ecosystem. During winter (October-February), riverine inputs of DIN predominate (> 80%) and are annually the most... |
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Palavras-chave: Strait of Dover; Nutrient cycles; River plumes; Atmospheric deposition; Coastal zone; Primary production. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2007.pdf |
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Lefebvre, Alain; Verin, Francoise. |
Avis de l’Ifremer concernant le projet d’arrêté préfectoral portant ouverture sanitaire temporaire de la zone à éclipse n°62.10 Baie de Canche / Hardelot-Le Touquet pour le groupe 2. La zone 62.10 est identifiée comme zone de production dont l’exploitation est soumise à autorisation préalable et sous conditions particulières (zone à éclipse) par arrêté préfectoral portant classement de salubrité des zones de production et de reparcage de coquillages vivants du département du Pas-de-Calais en date du 8 février 2018. Cette zone est non classée. Le suivi des zones à exploitation occasionnelle (dites à éclipses) doit suivre les règles applicables au classement et au suivi de certaines zones de production conchylicoles de l’instruction technique... |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00499/61081/64538.pdf |
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Arzul, Isabelle; Garcia, Celine; Joly, Jean-pierre; Miossec, Laurence; Chollet, Bruno; Robert, Maeva; Cuvelier, Nicolas; Lefebvre, Alain; Le Gagneur, Eric; Kopp, Joel; Mouillard, Gilbert; Gerla, Daniel; Le Saux, Jean-claude; Raguenes, Pierre; Le Gal, Dominique; Langlade, Aime; Bedier, Edouard; Nourry, Max; Martin, Jean-louis; Fillon, Alain. |
The REPAMO network (network ofmollusc pathology), created in 1986, ensures the survey of shellfish health status along French coasts according? to European Directives 91/67/EEC and 95/70/EEC. The aims of the network are 1 - to prevent the introduction and spread of exotic pathogens, 2-to study the means to decrease the impact of pathogens already present and to survey their evolution. In 2003, the REPAMO network focused on the survey oflisted diseases (bonamiosis and marteiliosis) in two areas under agreement process (Banc de Granville and zone X) and on the study of abnormal morlalities. Number of reported abnormal morlalities has increased in 2003. This rise can be partly explained by the recent network restructuring, but also by the summer heatwave and... |
Tipo: Text |
Palavras-chave: Réseau; Surveillance; Pathologie; Mollusques; Coquillages; Etat de santé; Network; Surveillance; Pathology; Molluscs; Shellfish; Health status. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00086/19699/17340.pdf |
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Garcia, Celine; Arzul, Isabelle; Chollet, Bruno; Francois, Cyrille; Goubet, Anne; Joly, Jean-pierre; Miossec, Laurence; Robert, Maeva; Cuvelier, Nicolas; Lefebvre, Alain; Le Gagneur, Eric; Ropert, Michel; Mouillard, Gilbert; Gerla, Daniel; Le Gal, Dominique; Rocher, Gregory; Langlade, Aime; Bedier, Edouard; Nourry, Max; Martin, Jean-louis; Costantini, Louis; Masson, Jean-claude; Martin, Anne-genevieve. |
Created in 1986, the REPAMO network (Network of mollusc pathology), is a national zoosanitary surveillance network of shellfish health status along the French coasts. Its activities are in keeping with two European Directives, 91 /67/EEC and 95/70/EC and are a patt of the institutional tasks ofIfremer. The aims of the network are to prevent the introduction and spread of exotic pathogens and to survey the evolution of notifiable pathogens already present in France. The network focused on the survey of listed diseases (bonamiosis and marteiliosis of flat oyster) in two areas under agreement process (Banc de Granville and zone X). In 2004, no sample couId be analysed to these two areas because of the difficulty to obtain flat oysters (sparse oyster beds,... |
Tipo: Text |
Palavras-chave: Réseau; Surveillance; Pathologie; Mollusques; Coquillages; Etat de santé; Network; Surveillance; Pathology; Molluscs; Shellfish; Health status. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00086/19702/17343.pdf |
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Garcia, Celine; Arzul, Isabelle; Chollet, Bruno; Ferrand, Sylvie; Francois, Cyrille; Joly, Jean-pierre; Miossec, Laurence; Robert, Maeva; Cuvelier, Nicolas; Lefebvre, Alain; Le Gagneur, Eric; Ropert, Michel; Mouillard, Gilbert; Gerla, Daniel; Le Gal, Dominique; Rocher, Gregory; Langlade, Aime; Bedier, Edouard; Nourry, Max; Martin, Jean-louis; Chabirand, Jean-michel; Fillon, Alain; Robert, Stephane; Courtois, Olivier; D'Amico, Florence; Rumebe, Myriam; Pichot, Yves; Le Gall, Patrik. |
Created in 1992, the REPAMO network (Network of mollusc pathology), is a national zoosanitary surveillance network of shellfish health status along the French coasts. Ils activities are in keeping with two European Directives, 91167/EEC and 95170/EC and are a part of the institutional tasks of Ifremer. The aims of the network are to prevent the introduction and spread of exotic pathogens and to sm'vey the evolution of notifiable pathogens already present in France. The network focused on the survey of listed diseases (bonamiosis and marteiliosis of flat oyster) in two areas under agreement process (Granville bed and zone X). In 2005, only samples of the Granville bed could be analysed due to the difflculty to obtain flat oysters (sparse oyster beds, beds... |
Tipo: Text |
Palavras-chave: Réseau; Surveillance; Pathologie; Mollusques; Coquillages; Etat de santé; Network; Surveillance; Pathology; Molluscs; Shellfish; Health status. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00086/19704/17346.pdf |
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Lefebvre, Alain; Grassi, Kelly; Caillault, Emilie. |
Installée dans la rade de Boulogne-sur-Mer et inaugurée le 25 novembre 2004, la station MARELCarnot mesure, toutes les 20 minutes, la salinité, la température de l’eau et de l’air, la fluorescence, la turbidité, la concentration en oxygène dissous, le pourcentage de saturation en oxygène, le P.A.R., l’humidité relative, la direction et la vitesse du vent, la hauteur d’eau et toutes les 12 heures, la concentration en nitrate, en phosphate et en silicium. Ce rapport vise à présenter les principaux éléments utiles à l’utilisateur des données afin de pouvoir adapter son étude en fonction de la disponibilité des données, de leur qualité et, bien entendu, de son objectif. Les résultats des paramètres température, salinité, turbidité, concentration et saturation... |
Tipo: Text |
Palavras-chave: Manche orientale; Boulogne-sur-Mer; Haute fréquence temporelle; MAREL; Hydrologie; Fluorescence.. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00590/70203/68230.pdf |
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Carpentier, Andre; Coppin, Franck; Dauvin, Jean-claude; Desroy, Nicolas; Dewarumez, Jean-marie; Eastwood, Paul D.; Ernande, Bruno; Harrop, Stuart; Kemp, Zarine; Koubbi, Philippe; Williams, Nigel Leader; Lefebvre, Alain; Lemoine, Michel; Loots, Christophe; S. Martin, Corinne; Meaden, Geoff J.; Ryan, Nick; Tan, Lei; Vaz, Sandrine; Walkey, Mike. |
INTRODUCTION: The Dover Strait (Figure 1) connects the North Sea to the English Channel. Here, northern France and South-East England are at their closest. This narrow corridor, one of the world's busiest straits for maritime shipping, is a key economic area for numerous activities, such as leisure and tourism, international ports and shipping, plus the exploitation of living or abiotic marine resources. This area is a significant resource for fisheries because many commercial fish species are abundant there, but also because of the presence of nursery and spawning areas and migratory routes linked to specific environmental characteristics. The vulnerability of these resources, which are subjected to strong anthropogenic pressures, has brought together... |
Tipo: Text |
Palavras-chave: Survey; Landings; Larvae; Eastern channel; Benthos; Fish; Sig; Policy analysis; Species protection; Habita protection; Protected areas; Marine biodiversity conservation. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/rapport-2350.pdf |
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Artigas, Luis Felipe; Didry, Morgane; Lampert, Luis; Broutin, Mathias; Bonato, Simon; Lizon, Fabrice; Lefebvre, Alain. |
L'élément de qualité phytoplancton doit être évalué dans le cadre de la Directive Cadre sur L’Eau grâce à trois indices : biomasse, abondance et composition. Les deux premiers indices, biomasse et abondance, ont déjà été définis. L’indice composition a quant à lui fait l'objet d'une proposition précise en Méditerranée, mais pas en Manche - Atlantique. Les travaux antérieurs montrent que la construction d'un indice de composition doit tenir compte de la diversité de l'ensemble du phytoplancton. Or, les comptages microscopiques ne concernent en général que le micro-phytoplancton. Il est donc nécessaire de prendre en compte des informations supplémentaires qui tiennent compte du nano- et du picophytoplancton, dont l'importance dans la diversité du... |
Tipo: Text |
Palavras-chave: Manche Orientale; Groupes phytoplanctoniques; Cytométrie en Flux de type Scanning; Fluorimétrie spectrale; Analyse CHEMTAX; Projet DYMAPHY. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00361/47258/47223.pdf |
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Grassi, Kelly; Poisson-caillault, Emilie; Bigand, André; Lefebvre, Alain. |
In the framework of ecological or environmental assessments and management, detection, characterization and forecasting of the dynamics of environmental states are of paramount importance. These states should reflect general patterns of change, recurrent or occasional events, long-lasting or short or extreme events which contribute to explain the structure and the function of the ecosystem. To identify such states, many scientific consortiums promote the implementation of Integrated Observing Systems which generate increasing amount of complex multivariate/multisource/multiscale datasets. Extracting the most relevant ecological information from such complex datasets requires the implementation of Machine Learning-based processing tools. In this context, we... |
Tipo: Text |
Palavras-chave: Clustering; Pattern discovery; Time series; Multi-Level Spectral Clustering; English Channel. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75481/76326.pdf |
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Phan, Thi-thu-hong; Poisson Caillault, Émilie Poisson; Lefebvre, Alain; Bigand, André. |
Time series with missing values occur in almost any domain of applied sciences. Ignoring missing values can lead to a loss of efficiency and unreliable results, especially for large missing sub-sequence(s). This paper proposes an approach to fill in large gap(s) within time series data under the assumption of effective information. To obtain the imputation of missing values, we find the most similar sub-sequence to the sub-sequence before (resp. after) the missing values, then complete the gap by the next (resp. previous) sub-sequence of the most similar one. Dynamic Time Warping algorithm is applied to compare sub-sequences, and combined with the shape-feature extraction algorithm for reducing insignificant solutions. Eight well-known and real-world data... |
Tipo: Text |
Palavras-chave: Imputation; Missing data; Univariate time series; DTW; Similarity. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00396/50696/51387.pdf |
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Hebert, Cyril; Lefebvre, Alain; Bucas, Karenn. |
Le littoral Nord/Pas-de-Calais - Picardie montre de nombreux signes de dysfonctionnement de l'écosystème reliés (à tort ou à raison ?) à l'activité humaine le long des côtes. Ces signes extérieurs sont le plus souvent identifiés comme un envahissement par certaines espèces, tant animales que végétales. Parmi ces espèces envahissantes, Phaeocystis sp. (algue phytoplanctonique) montre une prolifération régulièrement observée. Son cycle de vie semble, au moins en partie, fortement dépendant de la disponibilité des éléments nutritifs. Cette étude vise donc à quantifier les apports continentaux en éléments nutritifs des principaux fleuves côtiers du Pas-de-Calais. Ces estimations de flux, hebdomadaires, ont été calculées à l'aide de jaugeages (estimation des... |
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Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00083/19379/16973.pdf |
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Verin, Francoise; Caboche, Josselin; Lagache, Coralie; Lefebvre, Alain. |
A la demande de la Direction des Affaires Maritimes de Boulogne-sur-Mer, une étude sanitaire a été conduite sur la zone conchylicole « Baie de Canche : Hardelot/Le Touquet » en vue du classement de la zone de production pour le groupe 3 des coquillages bivalves non fouisseurs. Ce rapport présente un bilan des données disponibles sur la zone de production et les sources de contamination susceptibles d’impacter la zone de production. L’échantillonnage des coquillages moule a été réalisé sur le point de suivi « Dannes ». Les résultats des suivis microbiologique et chimique (dénombrement des Escherichia coli et teneur en métaux lourds Plomb, mercure et cadmium dans les coquillages) sont présentés et interprétés par rapport aux seuils réglementaires en vigueur.... |
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Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00684/79567/82233.pdf |
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Registros recuperados: 99 | |
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