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Inventory of Mäerl beds with Phymatolithon calcareum in the Pertuis Charentais Sea. Environmental state for 1940-2012

An inventory of mäerl ( unfixed red marine algae Corallinaceae with calcified arbuscular thalli) is taken in the Pertuis Charentais using the compilation of historical data and new observations over the period 2006-2012.

The geographic extent of the inventory includes Pertuis Breton, Antioch and Maumusson, extends from the Lay estuary in the north to the Bay of Marennes-Oléron in the south and includes the edges of the islands of Ré, Oléron and Aix.

Contributing to this inventory are, surveys DCE 2006 DCE, control monitoring DCE 2007 to 2012 under the aegis of Ifremer and Agences de l’Eau Loire-Bretagne and Adour-Garonne, surveys conducted for the Port Atlantique La Rochelle on the site of dredge spoil deposits in Lavardin from 2007 to 2012, surveys in 2007 FONSOLE by Ifremer and the surveys by Ifremer and laboratory LIENSs to map the crepidula stocks in the Pertuis Charentais Sea.

Adding specific surveys conducted in 2011 by the ship Estran by dredge on subtidal bottom sediments of Pertuis Breton and intertidal quadrat in 2012 on the periphery of the islands of Ré, Oléron and along the cliffs of Aytré. The positioning of ground truthing stations were identified by GPS or dGPS.

Initially identified by samples of the dredged material in October 2009 during the validation of sonar surveys to individualize stocks of crepidula, a live maerl bed is mapped in July 2011 in the harbor of Saint-Martin in Pertuis Breton. Its area is estimated at more than 2 km². Surveys of pedibus jambi conducted at the point of Grouin and Saint-Martin de Ré has confirmed the presence of live maerl scattered on the lower foreshore.

This suggests a scattering of live maerl thalli of several tens of km² around the main bed of Saint-Martin. It is also confirmed by the single algological extraction of Phymatolithon calcareum done at the beginning of the twentieth century in Saint-Martin de Ré by Dollfus, probably already on the lower foreshore as observed in 2012 near the Couronneau beacon.

Numerous dead maerl thalli in the procress of diagenesis have also been observed in the East and Southeast of Pertuis Breton and Antioch suggesting passive transport by contributions from live beds farther to the West, including Pertuis in Antioch. The presence of live maerl on the lower foreshore is seen very occasionally in the western islands of Oléron (Pointe Chassiron) and Ré (Phare des Baleines) via recent algologiques and fauna surveys.

In biogeographic terms, the maerl bed of Pertuis Breton is the easternmost and southernmost of those known in the Bay of Biscay.

The nearest mäerl beds known are respectively located in Noirmoutier (Bourgneuf Bay) and Galicia (Spain). These observations complement the atlas mapping of maerl populations in Europe published under the auspices of the OSPAR Convention. They provide a knowledge base for future conservation actions defined locally in the context of Natura 2000 Sea Marine Natural Park of the Gironde estuary and the Pertuis Charentais.

Simple

Date ( Creation )
2012-09-30T10:59:00
Identifier
FR-330-715-368-00198-ifr-MAERL-PERTUIS
Purpose
This shapefile was created for the purpose of an inventory map of mäerl Phymatolithon calcareum on the bottom sediments in the Pertuis Charentais Sea taking into account the historical and recent data acquired from 2006 to 2012.
Credit
LIENSs, Ifremer, Ré Nature-Environnement : acquisition des données LIENSs-CNRS-Université de la Rochelle : Pierre-Guy Sauriau & Cécile Curti, numérisation et validation scientifique
Status
On going
Originator
LIENSs, CNRS, Université de La Rochelle, Ifremer - P.-G. Sauriau, C. Curti, J. Jourde & P. Le Gall ( )
Author
LIENSs, CNRS, Université de La Rochelle, Ifremer - P.-G. Sauriau, C. Curti, J. Jourde & P. Le Gall ( )
Distributor
Ifremer - Sextant ( )
Processor
LIENSs, CNRS, Université de la Rochelle - C. Curti ( )
Custodian
LIENSs, CNRS, Université de la Rochelle - P.-G. Sauriau ( )
2 rue Olympe de Gouges 17000 La Rochelle ,
Point of contact
LIENSs, CNRS, Université de la Rochelle - P.-G. Sauriau ( )
Principal investigator
LIENSs, CNRS, Université de la Rochelle - P.-G. Sauriau ( )
Owner
CNRS/Ifremer/ Université de La Rochelle - ( )
User
LIENSs - ( )
Maintenance and update frequency
As needed
Thèmes Sextant Thèmes Sextant ( Theme )
  • /Biological Environment/Key Habitats/Maerl
Keywords ( Discipline )
  • Benthos, Maerl, algology, Phymatolithon calcareum
Keywords ( Place )
  • Pertuis Charentais Sea
Keywords ( Stratum )
  • 0 à +10 m
Keywords ( Temporal )
  • 2010
Keywords ( Theme )
  • Species distribution
Type de jeux de donnée ODATIS Type de jeux de donnée ODATIS ( Theme )
  • /Processed data/Composite products
Thématiques - SIMM Thématiques - SIMM ( Theme )
  • /Etat du Milieu/Habitats
Sous-regions marines Sous-regions marines ( Place )
  • Bay of Biscay
Use limitation
This file is for personal use and not commercial. For any purpose other than personal, please contact the distributor. Any modification of this data is subject to prior authorization. To do so, please contact the administrator of the data.
Access constraints
Copyright
Use constraints
Copyright
Other constraints
Required citation for the map : « Sources : P.-G. Sauriau, C. Curti, J. Jourde & P. Le Gall, 2012. Creation : C. Curti & P.-G. Sauriau, 2012 ; digital product LIENSs / CNRS / Université de la Rochelle / Ifremer / AELB »
Other constraints
Required citation for the bibliography: Sauriau P.-G., Curti C., Jourde J., Aubert F., Cajeri P., Lavesque N., Dubois S., Lepareur F., Gouesbier C., Sauriau F., Sauriau M., Latry L., Robert S., Leguay D., Pineau D. & Geairon P. (2012). Le maerl algues corallinacées marines dans les Pertuis Charentais. Annales de la Société des Sciences Naturelles de la Charente-Maritime, 10: 281-300.
Spatial representation type
Vector
Denominator
300000
Metadata language
fr
Character set
UTF8
Topic category
  • Biota
Environment description
Data collection: Collection by ground truth and by dredging and pedibus jambi and contour of GPS or dGPS treatment: report of GPS and dGPS readings in WGS84 for the mapping, import with ArcGIS 10.0 for georeferencing and digitizing the synthesis map in ArcGIS 10.0.
Begin date
2010-12-31T11:22:00
End date
2012-09-30T11:22:00
N
S
E
W
thumbnail


Reference system identifier
EPSG / WGS 84 (EPSG:4326) / 7.4
Topology level
Geometry only
Geometric object type
Surface
Geometric object count
3
Geometric object type
Point
Geometric object count
1017
Distribution format
  • shp ( 10 )

OnLine resource
sextant@ifremer.fr ( WWW:LINK )
Hierarchy level
Dataset

Conformance result

Date ( Creation )
2012-01-16
Explanation
not evaluated
Pass
No
Statement
Non renseignée
File identifier
d06bd2f5-0c0d-417c-be06-d6fa20557df4 XML
Metadata language
fr
Character set
UTF8
Hierarchy level
Dataset
Date stamp
2020-06-04T00:43:48
Metadata standard name
ISO 19115:2003/19139 - SEXTANT
Metadata standard version
1.0
Point of contact
Lienss CNRS Universite de la Rochelle - C. CURTI ( )
 
 

Overviews

overview

Spatial extent

N
S
E
W
thumbnail


Keywords

Species distribution
Thèmes Sextant
/Biological Environment/Key Habitats/Maerl
Thématiques - SIMM
/Etat du Milieu/Habitats
Type de jeux de donnée ODATIS
/Processed data/Composite products

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