Série biologique Huitre Creuse (réseau VELYGER)
Série biologique sur l'abondance larvaire et le recrutement de l'Huitre Creuse en Rade de Brest (réseau VELYGER)
Simple
- Date (Publication)
- 2022-02-21
- Citation identifier
- https://portail.indigeo.fr/geonetwork/srv/metadata/f21d2508-5603-47a9-b19f-6bffbe06a09e
- Status
- Under development
- Point of contact
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Organisation name Individual name Electronic mail address Role IFREMER-LEMAR
POUVREAU Stéphane
Author
- Maintenance and update frequency
- Annually
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GEMET - Concepts, version 2.4
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milieu marin
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mollusque
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coquillage
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écologie
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biosphère
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conservation des espèces
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conchyliculture
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invertébré
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INSPIRE themes
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Habitats et biotopes
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Continents, countries, sea regions of the world.
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France
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Régions administratives de France
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Bretagne
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- Use limitation
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Utilisation libre sous réserve de mentionner la source (a minima le nom du producteur) et la date de sa dernière mise à jour
- Access constraints
- Other restrictions
- Use constraints
- Intellectual property rights
- Other constraints
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Le fournisseur n’est pas en mesure de garantir l’exactitude, la mise à jour, l’intégrité, l’exhaustivité des données et en particulier qu'elles sont exemptes d'erreurs ou d'imprécisions, notamment de localisation, d’identification ou de qualification. Aucune garantie quant à l'aptitude des données à un usage particulier n'est apportée par le fournisseur. Les utilisateurs utilisent les données sous leur responsabilité pleine et entière, sans recours possible contre le fournisseur dont la responsabilité ne saurait être engagée du fait d’un dommage résultant directement ou indirectement de l’utilisation de ces données. En particulier, il appartient aux utilisateurs d’apprécier, sous leur seule responsabilité : l'opportunité d'utiliser les données; la compatibilité des fichiers avec leurs systèmes informatiques; l’adéquation des données à leurs besoins; qu’ils disposent de la compétence suffisante pour utiliser les données. Le fournisseur n’est en aucune façon responsable des éléments extérieurs aux données et notamment des outils d’analyse, matériels, logiciels, réseaux..., utilisés pour consulter et/ou traiter les données. L’utilisateur veille à vérifier que l’actualité des informations mises à disposition est compatible avec l’usage qu’il en fait.
- Spatial representation type
- Vector
- Denominator
- 0
- Language
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fre
- Character set
- UTF8
- Topic category
-
- Geoscientific information
- Oceans
- Biota
- Description
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France
![thumbnail](https://demo.georchestra.org/geonetwork/srv/api/regions/geom.png?geomsrs=EPSG:4326&geom=POLYGON((-4.2602%2048.3065,-4.2602%2048.3705,-4.3731%2048.3705,-4.3731%2048.3065,-4.2602%2048.3065)))
- Begin date
- 2008-01-01
- End date
- 2030-12-31
- Reference system identifier
- EPSG / RGF93 / Lambert-93 (EPSG:2154) / 7.4
- Distribution format
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Name Version ESRI Shapefile
1.0
- Distributor contact
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Organisation name Individual name Electronic mail address Role UMR6554 LETG CNRS (INDIGEO)
Publisher
- OnLine resource
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Protocol Linkage Name WWW:LINK-1.0-http--link
https://wwz.ifremer.fr/velyger/ Réseau National Velyger
WWW:LINK-1.0-http--link
https://portail.indigeo.fr/geocms/maps/portail-kwnkswjg/share#project visualisation et téléchargement
- Hierarchy level
- Dataset
Conformance result
- Date (Publication)
- 2013-10-21T00:00:00
- Explanation
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L’article 7, paragraphe 1, de la directive 2007/2/CE correspond aux modalités techniques de l’interopérabilité : il s’agit du règlement relatif à l’interopérabilité : règlement n°1253/2013 du 21 octobre 2013 modifiant et complétant le règlement n°1089/2010 du 23 novembre 2010
- Pass
- Yes
- Statement
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Database content 1: Larval concentration (number of individuals per 1.5 m3) of Crassostrea gigas
The method used to monitor larval concentration is the following : An important volume of seawater (1.5 m3) is pumped twice a week, throughout the spawning season (june-september), at one meter below the surface at high tide (+/- 2h). Water is filtered trough plankton net fitted with 40 µm mesh. After a proper rinsing of the net, the retained material is transferred into a polyethylene bottle (1 liter) and fixed with alcohol. At laboratory, sample is then gently filtered and rinse again and transferred into eprouvette. Two sub-samples of 1 mL are then taken using a pipette and examined on a graticule slide for microscope. The microscopic examination is made with a conventional binocular optical microscope with micrometer stage at a magnification of 10 X (or above). During the counting, a special care is necessary as larvae of other bivalves are also collected and confusion is possible. Larvae of C. gigas are also classified into four stage of development:
Stage I = D-shaped straight hinge larvae (shell length <105 µm)
Stage II = Early umbo evolved larvae (shell length between 105 and 150 µm)
Stage III = Medium umbo larvae (shell length between 150 and 235 µm)
Stage IV = Large umbo eyed pediveliger larvae (shell length > 235 µm)
Database content 2: Recruitment Index (number of recruit per benthic collector) of Crassostrea gigas.
Recruitment is evaluated on benthic collectors (experimental or professional) deployed to catch larvae. The benthic collectors used must meet several physical criteria to be attractive for oyster larvae, including (1) being physically and chemically similar to adult calcareous shells; (2) offering a coarse surface with fine relief; and (3) having a white colour as shells. It has also been shown that multi-plates 3D-structure with a narrow space between plates (< 2cm) and without inclination constitute a satisfying frame, allowing the availability of replicates. Lastly, the benthic collectors should not be deployed directly onto the sediment (to avoid problems of hypoxia and sedimentation), but some centimetres above it.
To meet all those criteria, the standardised benthic collector’s method revised and proposed by Pouvreau et al. (2021) for monitoring recruitment of native oyster consist uses a series (n=6) of rugged plates of a known surface area made of plastic (collectors cups used in shellfish farming) or cement (aragonites tiles used for aquarium). Furthermore, the plates have to be fully covered by a fine limed coating (2mm thick), which is obtained through a standard procedure (1kg of lime, 800mL of seawater and 15 days of drying time at temperature fixed between 20°C and 25°C in a high air renewal place). This step of coating is very important because it standardises the surface of the substrate (in terms of composition, texture, roughness and colour).
The benthic collectors should be deployed in replicate (for instance n=2x6 plates) at the bottom of the seafloor near the native oyster habitat for a continuous period of time. The deployment of these benthic collectors can be made from a boat with a mooring, by SCUBA divers or on the shore in the low intertidal area at low tide. After exposure, collectors are removed, gently rinsed and dried at the laboratory. Newly settled recruits are identified and counted by visually inspecting the top and bottom sides of each plate under standard binocular microscopes or more advanced 3D microscopes (e.g. KEYENCE VHX 6000). Care should be taken to avoid misidentification of other bivalve species. For each deployment date, a minimum of three plates from each of the two collectors (i.e. six cups in total) should be analysed to get a reliable mean and standard error. Recruitment should be reported as the number of individuals settled per cm2 within 15 days of exposure (for biweekly recruitment) or per collector at the end of the reproductive period.
Metadata
- File identifier
- f21d2508-5603-47a9-b19f-6bffbe06a09e XML
- Metadata language
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fre
- Character set
- UTF8
- Hierarchy level
- Dataset
- Date stamp
- 2022-03-15T15:53:24
- Metadata standard name
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ISO 19115
- Metadata standard version
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1.0
- Metadata author
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Organisation name Individual name Electronic mail address Role IFREMER LEMAR
POUVREAU Stéphane
Point of contact
Overviews
Spatial extent
![thumbnail](https://demo.georchestra.org/geonetwork/srv/api/regions/geom.png?geomsrs=EPSG:4326&geom=POLYGON((-4.2602%2048.3065,-4.2602%2048.3705,-4.3731%2048.3705,-4.3731%2048.3065,-4.2602%2048.3065)))
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