Almost invisible from land, eelgrass forms extensive underwater meadows. These aquatic grasslands grow in calm, salty waters.

Molluscs, crustaceans, fish… many species find shelter here to feed, reproduce or hide, making these environments small havens of biodiversity.

Highly sensitive to human activity, eelgrass has, unfortunately, disappeared from many sectors.

At the mouths of certain rivers, there are stretches of slightly salty water (lagoon), separated from the ocean by a sand bar. They are called tidal lagoons.

The combined action of the wind, waves and currents, commonly referred to as littoral drift, forms a sand bar that closes up the lagoon’s entrance.

At high tide, the saltwater runs over the sand bar, mixing with the brackish water imprisoned in the lagoon.