The Mousterlin Marsh Fouesnant

Three natural environments to explore

The site is made up of three major natural areas:

• The Mer Blanche (or Letty)

A coastal lagoon to the west of the pointe de Mousterlin, protected from the swell by a dune belt. Its water, which is entirely salty thanks to a direct connection with the ocean, is home to an abundance of marine life: sea bass, mullet, flatfish, molluscs, crustaceans, seaweed… A veritable larder for many birds!

• The Cleut Rouz and Kerambigorn dunes

Between the points of Mousterlin and Beg-Meil, these dunes form a natural barrier between the marsh and the ocean. There are two types of dune:

• • The embryonic dune, mobile and shaped by the oyats that fix the sand.
  • The white dune, set back and slightly more stable.
  • The grey dune, older and home to lichens, mosses and hardy plants such as wallflower.

• The Mousterlin Marsh

To the east of the headland, this marsh was transformed in the early twentieth century by the creation of dykes and canals as part of an agricultural reclamation project. Unlike the White Sea, the water here is brackish, with a mixture of fresh and salt water. There is a rich fish fauna and a wide variety of habitats:

• • Salt meadows, frequented by brant.
  • Wet meadows, rich in rare insects such as the barn owl.
  • Reed beds, home to the grey heron and kingfisher.

A Natura 2000 site: European recognition

From the Mer Blanche to Beg-Meil, the site has been classified Natura 2000 for the quality of its habitats: foreshore, dunes, lagoons, wet meadows, salt meadows, reed beds, etc.

Why this recognition?

Because this area :

• Serves as a nursery for juvenile fish,
• Home to many migratory and breeding birds,
• Provides a valuable refuge for local flora and fauna.

A protected site managed locally

Since 2018, the Communauté de communes du Pays Fouesnantais (CCPF) has been leading the management of the site, according to an action plan known as the DOCOB. This approach is being built in partnership with the communes, the State, associations, private owners and farmers.

Actions in place:

• Resalinisation of the marsh via an automatic valve (2014) to restore its lagoon-like character.
• Maintenance of the wet meadows (mowing, grazing by Nantes cows).
• Control of invasive plants.
• Protection of the dunes: restricted access to sensitive areas.
• Regular monitoring: water quality, fish populations, biodiversity.
• Raising awareness: signs in the field, educational events and activities.