Étang de Berre

Étang de Berre
source
Name	Étang de Berre
Location	Bouches-du-Rhône, Provence-Alpes-Côte d'Azur, France
Type	Lagoon
Inflow	Durance via Canal de Marseille au Rhône, Arc, Réaltor
Outflow	Mediterranean Sea
Area	155 km²
Max-depth	10 m
Cities	Martigues, Fos-sur-Mer, Marignane, Vitrolles, Istres

Étang de Berre Étang de Berre is a large brackish lagoon in the Bouches-du-Rhône department on the Provence-Alpes-Côte d'Azur coast of southern France. Positioned west of Marseille and north of the Mediterranean Sea, it is one of the largest lagoons on the European Union coast and a focal point for regional transportation, industry, and conservation efforts. Its hydrology, geology, history, ecology, economic role, and recreational use link it to many aspects of Provence and Occitanie development.

Geography and Hydrology

Étang de Berre lies between the Gulf of Lion shelf and the Étang de Berre lagoon complex, bordered by the municipalities of Martigues, Fos-sur-Mer, Marignane, Istres, and Vitrolles. The lagoon connects to the Mediterranean Sea through the narrow Caronte channel near Port-de-Bouc and historically through the Rove Tunnel linking to the Boulevard des Dames and the Harbor of Marseille. Major freshwater inputs include regulated flows from the Durance via the Canal de Marseille au Rhône, and local streams such as the Arc and the Réaltor. Tidal exchange, wind-driven circulation from the Mistral, and artificial water management by entities like EDF and regional water agencies control salinity gradients and residence times within the basin.

Geology and Formation

The basin formed during Neogene and Quaternary marine transgressions affecting the Rhone Basin and the Provence plain, inheriting a geomorphology influenced by Ligurian Sea regressions, Alpine orogeny uplift, and Holocene sedimentation. Substrate includes Pliocene and Pleistocene marls, conglomerates, and alluvial deposits from the Durance and Rhone River catchments, overlain by anthropogenic fills near Fos-sur-Mer. Karst processes linked to the Massif de l'Étoile and tectonic activity associated with the Alps and the Pyrenees shaped drainage patterns. Coastal engineering such as the construction and partial collapse of the Rove Tunnel altered connectivity and sediment dynamics.

History and Human Use

Human presence around the lagoon dates to Paleolithic and Neolithic settlements evidenced near Istres and Martigues, with later prominence during the Roman Empire when sites like Fos-sur-Mer and Marignane served as maritime and agricultural centers. Medieval development tied to feudal domains of Count of Provence and trade through the Port of Marseille expanded fisheries and salt extraction. Industrialization in the 19th and 20th centuries brought railways of the Chemins de fer de Provence and ports connected to the Suez Canal era commerce, while World Wars I and II saw strategic use by French Navy and Allied forces. Postwar projects including the Canal de Marseille au Rhône and petrochemical complexes reshaped land use and demographics.

Ecology and Environmental Issues

The lagoon supports habitats for waders, seabirds such as grey heron and greater flamingo occasional visitors, and fish communities including sea bass and mullet. Surrounding wetlands and reedbeds host flora typical of Mediterranean lagoons and species recorded by Conservatoire du littoral and regional natural parks. Environmental pressures include eutrophication driven by nutrient inputs from agriculture in the Rhone and Durance basins, industrial pollution from Fos-sur-Mer petrochemical complex and TotalEnergies facilities, and legacy contamination from heavy metals and hydrocarbons. Restoration and monitoring involve actors such as Agence de l'eau Rhône-Méditerranée-Corse, the Ministry of Ecological Transition, and academic teams from Aix-Marseille Université and CNRS, employing measures like aeration, wastewater treatment upgrades, and managed reconnection projects to the Mediterranean Sea.

Economy and Industry

The lagoon underpins a mixed economy: port operations at Fos-sur-Mer and small harbors in Martigues facilitate bulk handling, while petrochemical and steel industries cluster in the Fos industrial zone linking to multinational firms such as TotalEnergies and firms operating in the Port of Marseille-Fos. Airports including Marseille Provence Airport in Marignane and logistics corridors tied to the A7 autoroute support freight and passenger flows. Traditional activities—salt marshes, oyster and shellfish farming near Istres and artisanal fisheries in Martigues—coexist with tourism services and marine engineering contractors. Regional economic planning by Aix-Marseille-Provence Metropolis balances industrial growth with infrastructure investments in rail freight terminals and energy transition projects involving EDF and renewable initiatives.

Recreation and Tourism

Recreational use centers on sailing, windsurfing, angling, and birdwatching, with marinas in Martigues and sailing schools linked to the Fédération Française de Voile. Cultural tourism highlights archaeological sites around Fos-sur-Mer, medieval heritage in Marignane, and the canal engineering legacy of the Rove Tunnel which attracts technical visits. Proximity to Calanques National Park, the Camargue and the city of Marseille makes the lagoon a hub for day trips, cycling routes promoted by local councils, and gastronomy tied to Provençal markets and seafood restaurants frequented by visitors from Aix-en-Provence and Nice.

Category:Lagoons of France Category:Geography of Bouches-du-Rhône