The Étang de Thau (; ) or Bassin de Thau is the largest of a string of

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s (''étangs'') that stretch along the French coast from the

Rhône The Rhône ( , ; Occitan language, Occitan: ''Ròse''; Franco-Provençal, Arpitan: ''Rôno'') is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and Southeastern France before dischargi ...

river to the foothills of the

Pyrenees The Pyrenees are a mountain range straddling the border of France and Spain. They extend nearly from their union with the Cantabrian Mountains to Cap de Creus on the Mediterranean coast, reaching a maximum elevation of at the peak of Aneto. ...

and the border to

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

in the

Languedoc-Roussillon Languedoc-Roussillon (; ; ) is a former regions of France, administrative region of France. On 1 January 2016, it joined with the region of Midi-Pyrénées to become Occitania (administrative region), Occitania. It comprised five departments o ...

. Although it has a high salinity, it is considered the third largest lake in France.

Description

It is about long and 8 km wide, with an area of . The mean depth of the lagoon is , but in the central navigation channel it can be deep. Near Bouzigues is a depression with a diameter of . This 'Fosse de la Vise' is the source of a hot spring that feeds the spa in Balaruc. Its size and depth, which distinguish it from other lagoons of the region, is explained by the

geomorphology Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand wh ...

of the region since the

syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed ...

formed by

folding Fold, folding or foldable may refer to: Arts, entertainment, and media * ''Fold'' (album), the debut release by Australian rock band Epicure * Fold (poker), in the game of poker, to discard one's hand and forfeit interest in the current pot *Abov ...

produced the corresponding

anticline In structural geology, an anticline is a type of Fold (geology), fold that is an arch-like shape and has its oldest Bed (geology), beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex curve, c ...

of the Gardiole in the north-east. Until relatively recently, the lagoons from Marseillan to the

were a continuous stretch of inland waterway. Early settlers described this feature as "une petite mer intérieure et tranquille" ("a small, calm, inland sea"). It provided access to, in particular, Marseillan, a

fishing village A fishing village is a village, usually located near a fishing ground, with an economy based on catching fish and harvesting seafood. The continents and islands around the world have coastlines totalling around 356,000 kilometres (221,000 ...

that became a trade centre. Linked now by the

Canal du Rhône à Sète Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow u ...

to the river Rhône and by the

Canal du Midi The Canal du Midi (; ) is a long canal in Southern France (). Originally named the ''Canal Royal en Languedoc'' (Royal Canal in Languedoc) and renamed by French revolutionaries to ''Canal du Midi'' in 1789, the canal is considered one of the g ...

Bordeaux Bordeaux ( ; ; Gascon language, Gascon ; ) is a city on the river Garonne in the Gironde Departments of France, department, southwestern France. A port city, it is the capital of the Nouvelle-Aquitaine region, as well as the Prefectures in F ...

via

Toulouse Toulouse (, ; ; ) is a city in southern France, the Prefectures in France, prefecture of the Haute-Garonne department and of the Occitania (administrative region), Occitania region. The city is on the banks of the Garonne, River Garonne, from ...

, the lagoon also has access to the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

Sète Sète (; , ), also historically spelled ''Cette'' (official until 1928) and ''Sette'', is a commune in the Hérault department, in the region of Occitania, southern France. Its inhabitants are called ''Sétois'' (male) and ''Sétoises'' (fem ...

. There is also a small canal (''le canal des Allemands'' or the ''pisse-saume'') that links the western end to the sea at Marseillan Plage. This canal is only suitable for small craft since both road and railway bridges restrict height. To the east, between Balaruc and Sète, the borders of the lagoon are largely industrial. The south bank is formed by the coastal strip from Sète to

Cap d'Agde Cap d'Agde () is a seaside resort on France's Mediterranean coast. It is located in the commune of Agde, in the Hérault department within the region of Occitanie. Cap d'Agde was planned by architect Jean Le Couteur as part of one of th ...

. The northern side has villages dedicated to fishing and the production of shellfish. There are harbours in the towns of Marseillan, Mèze and Bouzigues, with smaller ports dedicated to shellfish on the northern shore. There is significant variation in the rainfall in the catchment basin for the lagoon, both seasonally and between years. The annual precipitation can range from 200 to 1,000 mm per year. As a result, the water temperature and salinity have extensive ranges. Water temperature ranges from 3 °C to 29 °C, with salinities of 27 to 40 psu. The salinity changes during the year with lows from February to June and peaks in July to January.

Administration

Located between the towns of

and Marseillan in the

Hérault Hérault (; , ) is a departments of France, department of the Regions of France, region of Occitania (administrative region), Occitania, Southern France. Named after the Hérault (river), Hérault River, its Prefectures in France, prefecture is M ...

département In the administrative divisions of France, the department (, ) is one of the three levels of government under the national level (" territorial collectivities"), between the administrative regions and the communes. There are a total of 101 ...

, the Étang de Thau is shared administratively by the

communes A commune is an alternative term for an intentional community. Commune or comună or comune or other derivations may also refer to: Administrative-territorial entities * Commune (administrative division), a municipality or township ** Communes of ...

of (running clockwise),

Balaruc-le-Vieux Balaruc-le-Vieux (; ) is a Communes of France, commune in the Hérault Departments of France, department in the Occitania (administrative region), Occitanie Regions of France, region in southern France. Population See also *Communes of the ...

, Balaruc-les-Bains,

Frontignan Frontignan (; ) is a commune in the Hérault department in southern France. Frontignan is renowned for its AOC wine, the Muscat de Frontignan, a sweet wine made solely from the Muscat grape variety. Geography Frontignan is located in th ...

, Sète, Marseillan, Mèze, Loupian and Bouzigues.

Economy and natural resources

As the lagoon is open to the sea, it has fish such as the

gilt-head bream The gilt-head bream (''Sparus aurata''), also known as the gilthead, dourade, gilt-head seabream or silver seabream, is a species of marine Actinopterygii, ray-finned fish belonging to the Family (biology), family Sparidae, the seabreams or porg ...

(''dorade''), the meagre (''maigre'', a kind of croaker) and the

sea bass Sea bass is a common name for a variety of species of marine fish. Many fish species of various families have been called sea bass. In Ireland and the United Kingdom, the fish sold and consumed as sea bass is exclusively the European bass, ''Dic ...

. The lagoon produces approximately 200 kg/ha/year of fish. However, the shellfish industry is more economically important. Eighteen varieties of shellfish are taken from the lagoon - the most important being

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

s. 750 producers farm 2,750 oyster tables and take some 13,000 tonnes annually. This provides for about 8.5% of France's consumption. Oysters from the Étang de Thau are marketed under the name ''huîtres de Bouzigues'' (Bouzigues oysters) after the village of Bouzigues where oyster production started. They are a cupped variety. Fixed with cement to ropes, the young oysters are immersed in the water until they reach a size suitable for consumption. Thau water is graded A and so shellfish can be caught and consumed within minutes. In addition to oysters, some 3,000 tonnes of mussels are produced every year. Apart from fishing and shellfish, the Étang de Thau provides income through tourism, particularly via sailing schools.

Wildlife

The Bassin de Thau provides a habitat for a variety of wild animals, notably birds such as

herons Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 75 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus '' Botaurus'' are referred to as ...

and

pink flamingos ''Pink Flamingos'' is a 1972 American surrealist independent black comedy film by John Waters. It is part of what Waters has labelled the "Trash Trilogy", which also includes '' Female Trouble'' (1974) and '' Desperate Living'' (1977). The f ...

and a rich marine fauna, including

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

(oysters and mussels),

jellyfish Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animal ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, and

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

. Periodically in the spring and summer, the Thau Lagoon has algae blooms of '' Alexandrium catenella'' which sometimes reach such high levels that it results in contamination of the lagoon's bivalves with algae toxins.

Gallery

File:Étang de Thau, Mèze 07.jpg, Étang de Thau and

from Mèze File:Lido de Thau, Sète cf04.jpg, ''Lido de Thau'' with the Étang de Thau on the left, former

salt evaporation pond A salt evaporation pond is a shallow artificial salt pan designed to extract salts from sea water or other brines. The salt pans are shallow and expansive, allowing sunlight to penetrate and reach the seawater. Natural salt pans are formed thr ...

s on the right File:Dawn on Sète and the Étang de Thau.jpg, Sète and the Étang de Thau at dawn File:Harbour of Mèze at blue hour 01.jpg, Harbour of Mèze File:Lido de Thau, Sète, Hérault 07.jpg, The Île de Thau neighbourhood and the Étang de Thau seen from the "Lido de Thau" in

File:Bouzigues Parcs Moules.jpg,

Oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

production at Bouzigues File:Canal Midi Onglous.jpg,

joins Étang de Thau in Marseillan File:Leuchtturm Canal du Midi-Etang de Thau-DSC 0262w.jpg, ''Phare des Onglous'' lighthouse at the mouth of Canal du Midi

Notes

External links

Website of panoramic photos of the Thau lagoon and its region

{{DEFAULTSORT:Etang De Thau Thau Thau, Etang de Thau Lagoons of Europe Bodies of water of France Gulf of Lion