Thau

Thau, also known as the Étang de Thau, is a large coastal lagoon on the Mediterranean coast of southern France, located in the Hérault department in the Occitanie region. It lies along the coast between the port city of Sète to the north and the towns of Bouzigues, Mèze, Frontignan and Marseillan to the south. The lagoon is connected to the Mediterranean by a narrow channel near Sète, allowing tidal exchange, and receives freshwater inputs from small streams, giving it brackish water.

The Étang de Thau is notable for its shellfish industry and is one of Europe’s most important oyster and mussel production areas. Mussels and oysters are cultivated on lines and racks across the calm waters, and products are distributed to markets and restaurants across France and beyond. Several ports and villages along the shore support fishing, aquaculture, processing, and tourism.

Ecologically, the lagoon supports wetlands, birds and aquatic life, though it faces environmental pressures from nutrient inputs and development in surrounding areas. Management efforts focus on maintaining water quality, promoting sustainable aquaculture, and balancing economic activity with biodiversity conservation.

Economy and culture: Beyond shellfish farming, the area attracts visitors for beaches, boating and seafood gastronomy. Sète serves as a major port and cultural hub, while nearby towns such as Bouzigues are known for their seafood markets and local maritime traditions.