Consulta: creatorFacets:"Le Gall, Erwan"
Registros recuperados: 11
Data/hora: 03/06/2024 07:27:00

Nutrient and phytoplankton distribution in the Loire River plume (Bay of Biscay, France) resolved by a new Fine Scale Sampler
Provedor de dados: 5
Autores: 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

Subtidal Microphytobenthos: A Secret Garden Stimulated by the Engineer Species Crepidula fornicata
Provedor de dados: 5
Autores: Androuin, Thibault; Polerecky, Lubos; Decottignies, Priscilla; Dubois, Stanislas; Dupuy, Christine; Hubas, Cedric; Jesus, Bruno; Le Gall, Erwan; Marzloff, Martin; Carlier, Antoine.
The slipper limpet Crepidula fornicata is an emblematic invasive species along the northeast Atlantic coast. This gregarious gastropod lives in stacks of several individuals and forms extended beds in shallow subtidal areas. The effects of this engineer species on the colonized habitat can be physical (e.g., presence of hard-shell substrates with uneven topography) or biological (e.g., nutrient enrichment by direct excretion or via biodeposition). We hypothesized that through biological activity, nutrient fluxes at the sediment-water interface are enhanced, leading to stimulated primary productivity by microphytobenthos (MPB) associated with Crepidula beds. To test this fertilization hypothesis, we conducted a 10-day mesocosm experiment using C. fornicata...
Tipo: Text
Palavras-chave: Crepidula fornicata; Engineer species; Subtidal microphytobenthos; Fertilization; Hyperspectral imaging.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00472/58338/60893.pdf

Acquisition de données en vidéo sous-marine sur les ulves offshore de la baie de Douarnenez
Provedor de dados: 5
Autores: Lunven, Michel; Le Gall, Erwan; Gaffet, Jean-dominique.
In the Bay of Douarnenez, assessments of the offshore ulva stock have been carried out in 2004 and 2005 using some submarine video techniques. Altogether, 4 campaigns have been conducted during this period of time, enabling an estimate of the ulva biomass lying on the ocean bed, off the tidal zone, at depths of 2 to 20 metres.
Tipo: Text
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/rapport-6325.pdf

Développement d'un drone nautique pour le prélèvement d'échantillons d'eau en milieu côtier et estuarien (SPEEdoo)
Provedor de dados: 5
Autores: 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

In situ video and diffraction analysis of marine particles
Provedor de dados: 5
Autores: Lunven, Michel; Gentien, Patrick; Kononen, K; Le Gall, Erwan; Danielou, Marie-madeleine.
A design for a new underwater video-system to detect and observe suspended particles is presented. Particles are collected and isolated in a rectangular box where they are highly illuminated by a white light plane. The total field of view is determined. The camera, equipped with a remote controlled zoom, can resolve particles sizes ranging from 25 mum to several millimetres. Real-time image analyses are therefore performed. Particle counts and size spectra are calculated and displayed. Total light intensity scattered by the illuminated particles is closely related to the back-scattering values determined by an optical back-scatter sensor. A particle size analyser using diffraction analysis is associated to this video-system on a custom profiler....
Tipo: Text
Palavras-chave: Image analysis; Fine scale distribution; Flocculation; Suspended matter; In situ measurement.
Ano: 2003
URL: https://archimer.ifremer.fr/doc/2003/publication-504.pdf

A surface plasmon resonance system for the underwater detection of domoic acid
Provedor de dados: 5
Autores: 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
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00324/43481/42921.pdf

Monitoring of sea scallops Placopecten magellanicus in bottom seeding trials using video in Miquelon bay, Saint Pierre et Miquelon, France
Provedor de dados: 5
Autores: 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

Méthode de cartographie quantitative des fonds marins par vidéo. Application au suivi des semis de Placopecten magellinacus en Rade de Miquelon.
Provedor de dados: 5
Autores: 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...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00144/25516/23656.pdf

Vertical distribution of phytoplankton communities and relationships with physico-chemical parameters resolved by a fine scale sampler
Provedor de dados: 5
Autores: Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain.
Many studies in coastal areas have shown the existence of thin chemical and biological layers. Their thickness and vertical extension are mainly controlled by hydrological and physical forcing. An accurate description of the phytoplankton communities growing within these layers is difficult to obtain without a well-adapted sampling system. A new Fine Scale Sampler (FSS) has been designed in Ifremer in order to study phytoplankton distribution and associated dissolved properties in high stratified water column. This FSS consists in a vertical array of 15 sampling bottles, horizontally laid with 20 cm intervals. Data acquired from a CTD and Fluorescence probe provide a precise FSS positioning at the depth of highest density gradient or at chlorophyll a...
Tipo: Text
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxine.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00144/25493/23647.pdf

Acquisition de données sur l'expansion de Caulerpa taxifolia et Caulerpa racemosa en rade d'Hyères et en rade de Toulon (France)
Provedor de dados: 5
Autores: 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

A new device for in situ video and fluorescence analysis of marine particles. Applications to phytoplankton studies.
Provedor de dados: 5
Autores: 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