Flora and Fauna of the Mont Saint Michel Bay
The bay of Mont Saint-Michel is a working ecosystem as much as a view: 500 square kilometers of mudflats and salt marsh rebuilt twice a day by the largest tides in continental Europe, grazed by sheep, fished for mussels, and crossed by hundreds of thousands of migrating birds.
The Salt Marshes and the Famous Lamb
The herbus, the salt meadows between the sea walls and the flats, grow salt-tolerant plants: glasswort, sea purslane, and the grasses the sheep graze. Lamb raised on these marshes, agneau de pré-salé, carries a protected designation and a faint saltiness from the pasture itself, and appears on menus across the region. The marsh plants change color through the year, red-brown in autumn when the glasswort turns.
Birds, Seals, and Shellfish
The bay sits on the East Atlantic flyway, and the flats feed waders by the tens of thousands in passage and winter: oystercatchers, godwits, curlews, and plovers working the mud as the tide turns. A colony of harbor seals lives in the bay year-round, hauled out on sandbanks at low water and sometimes visible on guided bay walks. Offshore, rows of wooden stakes carry the bouchot mussels the bay is known for, the first shellfish in France to earn an AOP designation, in season from summer into winter. Bring binoculars two hours either side of low water; the birds work closest then, and our tides page explains the clock everything here runs on.
Frequently Asked Questions
What is pré-salé lamb?
Lamb raised on the bay’s salt meadows, where the salt-tolerant pasture flavors the meat. It carries a protected designation and is the signature dish of the Mont Saint-Michel region.
Are there seals in the bay of Mont Saint-Michel?
Yes. A colony of harbor seals lives in the bay year-round, resting on sandbanks at low tide. Guided bay walks sometimes pass within sight of them.
When is the best birdwatching in the bay?
Migration seasons, spring and autumn, and winter, when waders feed on the flats in large numbers. Work the two hours either side of low water, when the birds feed closest to the shore paths.