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| Registros recuperados: 37 | |
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| Lunven, Michel; Lehaitre, Michel; Nascimben, Eric; Rouvillain, Julien; Berric, Roger; Le Gall, Erwan; Gentien, Patrick. |
| A new video-microscope has been developed for in situ investigation on marine particles. A field of view is produced by a laser beam at 473 nm. Individual cells or particles that entered this field of view appear as individual diffraction-limited spots of light, which are resolved from the dark background. A mobile high-pass optical filter (610 nm) can be controlled and displaced in front of the CCD camera, allowing simultaneously imaging and discrimination between fluorescing and non-fluorescing particles. We have the possibility to add a band pass filter for phycoerytrin detection. The system allows white light visualisation of particles ranging from 10 µm to several millimetres, depending on the zoom magnification. With the 610 nm high pass filter, the... |
| Tipo: Text |
Palavras-chave: Surveillance; Phytoplancton; Phycotoxine. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00144/25495/23649.pdf |
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| Colas, Florent; Crassous, Marie-pierre; Laurent, Sebastien; Litaker, Richard W.; Rinnert, Emmanuel; Le Gall, Erwan; Lunven, Michel; Delauney, Laurent; Compère, Chantal. |
| Over the past decade Surface Plasmon Resonance (SPR) techniques have been applied to the measurement of numerous analytes. In this article, an SPR biosensor system deployed from an oceanographic vessel was used to measure dissolved domoic acid (DA), a common and harmful phycotoxin produced by certain microalgae species belonging to the genus Pseudo-nitzschia. During the biosensor deployment, concentrations of Pseudo-nitzschia cells were very low over the study area and measured DA concentrations were below detection. However, the in situ operational detection limit of the system was established using calibrated seawater solutions spiked with DA. The system could detect the toxin at concentrations as low as 0.1 ng mL−1 and presented a linear dynamic range... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00324/43481/42921.pdf |
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| Belsher, Thomas; Lunven, Michel; Le Gall, Erwan; Caisey, Xavier; Dugornay, Olivier; Mingant, Christian. |
| The oceanographic cruise Califa 2000, as the previous cruise, which concerned the "Parc National de Port-Cros", had for its principal objective to furnish some elements susceptible to help in the control of Caulerpa taxifolia expansion and in the protection of particularly sensitive areas (national parks, patrimonial sectors, regions of socio-economic importance). The cruise lasted from the 4th to the 21st of September 2000 in the rade d'Hyeres, Porquerolles island included, and the rade of Toulon. This detailed prospection gives a location of C. taxifolia and C. racemosa, a new invasive seaweed. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved. |
| Tipo: Text |
Palavras-chave: Rade de Toulon; Rade d' Hyeres; Cartography; Caulerpa racemos; Caulerpa taxifolia; Invasive species; Rade de Toulon; Rade d'Hyères; Cartographie; Caulerpa racemosa; Caulerpa taxifolia; Espèces invasives. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-520.pdf |
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| Landeira, Jose Maria; Ferron, Bruno; Lunven, Michel; Morin, Pascal; Marie, Louis; Sourisseau, Marc. |
| Phytoplankton blooms are usually dominated by chain-forming diatom species that can alter food pathways from primary producers to predators by reducing the interactions between intermediate trophic levels. The food-web modifications are determined by the length of the chains; however, the estimation is biased because traditional sampling strategies damage the chains and, therefore, change the phytoplankton size structure. Sedimentological studies around oceanic fronts have shown high concentrations of giant diatom mats (>1 cm in length), suggesting that the size of diatom chains is underestimated in the pelagic realm. Here, we investigate the variability in size and abundance of phytoplankton chains at the Ushant tidal front (NW France) using the Video... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00186/29730/28148.pdf |
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| Daniel, Anne; Rousseaux, Patrick; Le Gall, Erwan; Perchoc, Jonathan; Lunven, Michel. |
| A nautical drone was designed for the monitoring of estuarine and coastal waters in the context of the Water Framework Directive (WFD) to : - go up to 500 m off the coastline in less than 5 minutes, - perform in situ measurements (temperature, salinity, turbidity), - collect water samples for later analysis in the laboratory (phytoplankton identification, chlorophyll, nutrients, ...). |
| Tipo: Text |
Palavras-chave: Nautical drone; Water sampling; Coastal and estuarine waters. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00350/46094/45786.pdf |
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| Jourdin, Frederic; Tessier, Caroline; Le Hir, Pierre; Verney, Romaric; Lunven, Michel; Loyer, Sophie; Lusven, Andre; Filipot, Jean-francois; Lepesqueur, Jeremy. |
| A pair of self-contained acoustic Doppler current profilers (SC-ADCPs) operating with different frequencies were moored on a muddy sea bottom at about 20 m depth in the Bay of Vilaine off the French Atlantic coast. With their acoustic beams oriented upwards, the SC-ADCPs ensonified most of the water column. The results of several months of in situ recorded echo intensity data spanning 2 years (2003 to 2004) from the dual-frequency ADCPs are presented in this paper. The aim was to estimate suspended particle mass concentration and mean size. A concentration index CI is proposed for the estimation of particle concentration. Based on theory the CI-unlike the volume backscatter strength-does not depend on particle size. Compared with in situ optical data, the... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00213/32427/30896.pdf |
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| Dewamurez, J.m.; Lunven, Michel; Toularastel, France. |
| Dans le cadre de son programme d'équipement nucléaire, Electricité de France a confié au Centre National pour l'Exploitation des Océans la réalisation d'une étude de deux ans sur la croissance des moules. Le but du contrat était de mieux connaitre les modalités de la croissance de ces mollusques en fonction de la qualité du milieu où ils vivent. Les sites concernés par cette étude sont Gravelines, Penly, Plogoff. L'étude sur le site de Gravelines est effectuée à Wimereux par J.M. DEWAMUREZ, celle sur les sites de Plogoff et Penly à Brest (au COB) par M. LUNVEN et F. TOULARASTEL. Bien que répondant à la même question, les deux parties de l'étude sont traitées un peu différemment quant aux méthodes envisagées, elles sont réunies dans le présent rapport tout... |
| Tipo: Text |
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| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/00105/21605/19185.pdf |
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| Lunven, Michel; Guillaud, Jean-francois; Crassous, Marie Pierre; Youenou, Agnes; Gohin, Francis; Huret, Martin; Danielou, Marie-madeleine; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| Inscrite dans le cadre du Grand Défi Golfe de Gascogne, la campagne VILOIR a été réalisée du 19 au 26 Juin 2003 à bord du Côtes de la Manche avec pour objectif l’étude en période estivale des structures hydrologiques et phytoplanctoniques des panaches de la Loire et de la Vilaine. Elle fait suite, sur la même thématique, à la campagne hivernale NUTRIGAS (2001) et à la campagne printanière GASPROD (2002). |
| Tipo: Text |
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxines; Bretagne; Pays de Loire. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00144/25494/23648.pdf |
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| Petitgas, Pierre; Huret, Martin; Doray, Mathieu; Bourriau, Paul; Lunven, Michel. |
| Since 2000, the yearly acoustic pelagic survey of Ifremer in the Bay of Biscay designed for fish stock assessment of small pelagic fish has been converted into an integrated pelagic ecosystem monitoring plateforme. This has been achieved by coupling sensors and automating data acquisition streams. The data series now spans from 2000 to 2014. Together with data sensors and sampling designs, we present here an integrated study allowing to understand the spawning process of anchovy. We compare the maps of anchovy eggs obtained with CUFES (continuous underway fish egg sampler) with that of their spawning adults sampled at the same time by acoustics and identification trawl hauls. The distributions of eggs are surprisingly different than that of adults, with in... |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00281/39177/37738.pdf |
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| Lunven, Michel; Robert, Stephane; Caisey, Xavier; Rodriguez, Julien; Detcheverry, Sebastien; Gaffet, Jean-dominique; Le Gall, Erwan; Vasquez, Mickael. |
| Ce poster présente une méthodologie d’investigation des fonds marin par vidéo sous marine. Le système est constitué d’un bâti intégrant une caméra, un projecteur, un altimètre ainsi que des pointeurs laser. Les images vidéo des fonds marins sont retransmises et enregistrées à bord du navire sur disque dur et magnétoscope numérique DVCAM. Lors des profils vidéo, le logiciel de gestion VIDEONAV permet de constituer un fichier de navigation intégrant les positions géographiques, le code temps du magnétoscope ainsi que la surface visualisée calculée à partir de la hauteur de prise de vue par rapport au fond. En temps différé, VIDEONAV permet le rejeu de la navigation et des bandes vidéo associées dans le but de compléter ou de générer des fichiers de... |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00144/25516/23656.pdf |
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| Robert, Stephane; Le Moine, Olivier; Lunven, Michel; Caisey, Xavier; Gaffet, Jean-dominique; Le Gall, Erwan; Vasquez, Mickael; Rodriguez, Julien; Detcheverry, Sebastien; Goulletquer, Philippe. |
| Placopecten magellanicus production in Saint Pierre et Miquelon (NW North Atlantic) has been developed through direct seeding of juveniles on leased areas. However, most of the culture occurs in deep water ranging from 30 to 70 meters, which requires a monitoring by video to facilitate the grow-out and survival evaluation. In August 2008, a submersible leaded structure was connected by a video cable to the surface and observation screen was defined through the video, an altimeter and two lasers. The pictures were recorded on board on hard drive and digital video recorder DVCAM, and data were georeferenced by VIDEONAV software. Analysing the video tapes allows to establish a thematic database on the ground structure, presence or absence of seeded and wild... |
| Tipo: Text |
Palavras-chave: Scallops; Placopecten magellanicus; GIS; Monitoring; Miquelon Bay. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00134/24544/22576.pdf |
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| Gentien, Patrick; Lunven, Michel; Lazure, Pascal; Youenou, Agnes; Crassous, Marie-pierre. |
| Karenia mikimotoi is one of the most common red-tide dinoflagellates proliferating in the eastern North Atlantic and around Japan. Kills of marine fauna are associated with its blooms. In mixed water columns it migrates vertically, while in stratified water columns, the population remains confined within pycnocline layers. Wind events, increasing mixing and agitation initiate declines in its populations. This paper is focused on the formulation of mortality rate relative to shear rate. Autotoxicity is demonstrated by the use of a synthetic toxin. Bioconvection observed in cultures allows the establishment of a trade-off between phototropism, which leads to the local accumulation of cells, and their autotoxicity, which would prevent cell concentration. The... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2436.pdf |
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| Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| A new Fine Scale Sampler (FSS) was designed and used in the Loire River plume (Bay of Biscay, France) in order to study phytoplankton distribution in highly stratified water columns. The FSS consists of a linear array of 15 sampling bottles, set horizontally at 20 cm intervals. Data acquired from the CTD and fluorescence probe of the FSS enable it to be precisely positioned at the depth of the highest density gradient or at the chlorophyll a maximum. The FSS made it possible to investigate fine scale vertical distribution of phytoplankton and relationships with water density, nutrient concentrations or light availability, for spring and summer conditions. Under spring conditions, the entire upper layer exhibited a dominant diatom population (Chaetoceros... |
| Tipo: Text |
Palavras-chave: Plankton patchiness; Density discontinuity; Sampling; Thin layer; Nutrients; Phytoplankton. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-533.pdf |
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| Colas, Florent; Tardivel, Morgan; Evrard, Justine; Forest, Bertrand; Crassous, Marie-pierre; Lunven, Michel; Danielou, Marie-madeleine. |
| This deliverable contains all development work of the FastCAM, new tool for fast imaging of the phytoplankton, which took place in 2015. It consists of: One report of the FastCAM and its comparison with the FlowCAM presentation: The FlowCAM enables the digitalization of a sample of phytoplankton with X10 and X 4 magnifications. The first allows a better morphological description and therefore a higher taxonomic resolution but with a longer scan time (16 X). Thus, for routine analyses, only scanning at 4 X is possible. A considerable gain would be able to do an acquisition to the magnification 10 X with a time of analysis more short, comparable to 4 X. A fast flow imaging system has therefore developed in this sense. He was called FastCAM. The system is... |
| Tipo: Text |
Palavras-chave: FlowCAM; FastCAM; Imagerie rapide; Phytoplancton; REPHY.; FlowCAM; FastCAM; Fast imaging; Phytoplankton; REPHY. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00363/47420/47425.pdf |
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| Lunven, Michel. |
| This intervention is in line with the monitoring study which followed the shipwreck of the chemical tanker ECE 40 miles west of the Cap de la Hague. It aims to carry out some targeted samplings (in deep water, away from the shipwreck) in order to spot and quantify a possible chemical pollution linked to phosphoric acid leaking out of the ship's tanks. |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6324.pdf |
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| Registros recuperados: 37 | |
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