"Marsh" database: characterization of the state of the necton in two depolderized zones of the Gironde estuary
In the Gironde estuary, two accidentally de-polderized marshes have been the subject of biological monitoring (necton) since 2008: the Marais de Mortagne-sur-Gironde and the northern part of Île Nouvelle. The Mortagne-sur-Gironde marsh is located in the mesohalin sector of the Gironde estuary. With an area of 191 hectares, the marsh was dammed in 1966 and cultivated for more than 30 years. Its protective dike gave way during the December 1999 storm. Ile Nouvelle is located in the Oligaline Sector of the Gironde Estuary. The northern part of the island - an area of 141 hectares - has been depolderized during the passage of storm Xynthia in 2010, following the opening of a breach.
Biological monitoring (necton) was carried out in the Gironde estuary over the period 2008-2016 to test the hypothesis that the depoldisation of the estuarine shorelines makes it possible to recreate nursery and feeding areas for fish and fish. estuarine and coastal macrocrustaceans. This work was carried out by the National Institute for Research in Science and Technology for the Environment and Agriculture (Irstea), in partnership with the Conservatoire du Littoral, the Gironde Departmental Council and the Regional Council for Natural Areas ( CREN) of Poitou-Charentes.
The "Marsh" database includes all the surveys carried out throughout the study, between 2008 and 2016, and in particular samplings carried out within the necton.