Dragey Dunes / Claire-Douve Marsh

In the Bay of Mont-Saint-Michel, between the Bec d’Andaine and the Pignochet beach of Saint-Jean-le-Thomas, the intervention area within the project framework consists of a dune massif stretching 5 kilometers and the Claire Douve marsh located inland, spanning the communes of Saint-Jean-le-Thomas, Dragey-Ronthon, and Genêts, as well as the public maritime domain.

Since the 1950s, the sea has eroded more than 350 meters of the dunes bordering the beach on the northern part of the dune massif, while central and southern sectors have received significant sediment deposits. This configuration of dunes and back-dune marshes makes this site unique. It is classified as a Natura 2000 site, a ZNIEFF 1 zone (area of great biological or ecological interest), and partially listed as a UNESCO World Heritage site.

The site hosts many uses, which increase during the summer: beach activities, dune and marsh agriculture, horseback riding on the public maritime domain, hiking, including the passage of the long-distance hiking trail GR 223. This trail is threatened by severe erosion at certain points along its route.

Since the 1980s, parcels of land have been acquired by the Conservatoire du Littoral, with management entrusted to SyMEL (Mixed Syndicate for Coastal Spaces of Manche), particularly for site management work, usage agreements with agricultural operators, and relations with local stakeholders.

Fauna and flora

Regarding the flora, one can notably observe the Ophioglossum-leaved buttercup, bulbous rye-grass, lake bulrush, broad-leaved catchfly, and others.

The site is also a nesting area for many bird species such as the sand martin, reed warbler, spotted crake, and water rail. Located close to the Bay of Mont-Saint-Michel, the marsh plays an important role during wintering and pre-breeding migrations, especially for the wigeon, teal, black-tailed godwit, Eurasian spoonbill, and green sandpiper.