Oysters.us - Spat Perceptions Introduction

Oysters of Arcachon
John McCabe

The oyster region of Arcachon reaches from the estuary of the Gironde River south to the big Arcachon Bay, and then all the way down to the border of Spain. As the name of this oyster region suggests, the huge triangular Arcachon Bay is of key importance to this region. It covers about 37,000 acres (15,000 hectares) and opens to the Atlantic Ocean at a place called Cap Feret. The Arcachon Bay, although connected to the sea, is reminiscent of a land-locked sea. Many charming fishing villages are sprinkled along its perimeter. The weather is usually pleasantly warm and the locals are laid back and friendly. An island called "Ile aux Oiseaux" ("Island of the Birds") is located right in the middle of the bay. The seashore is also delightful. The largest sand dune in Europe can be found along the 52 miles of pristine beach. Located only about an hour drive time from the charming City of Bordeaux, the Arcachon Bay is the perfect place to take a vacation - and to feast on lots of fabulous oysters and other seafood.

In the course of the last few decades, the fishery business on the south side of Arcachon Bay (between La Teste and Gujan) has become very industrialized. It is considered the commercial hub of this area. In Port de Larros (right next to the town Gujan), traveling oyster lovers are invited to visit an interesting "oyster museum" called "La Maison de l'Huître". A marvelous oyster festival also takes place here every year (usually in August). It's called "Larros en Fête - Foire aux Huîtres".

Over on the north side of Arcachon Bay, little towns like Cassy, Lanton, Taussat and Audenge) exude a pleasantly rustic atmosphere . A number of small oyster operations are located in this area. Particularly the town Andernos is popular among tourists, as it features the perfect mix of rustic lifestyle, great shopping and a vibrant fish market to boot.

For centuries, the name "Arcachon" has been synonymous with "lots of great oysters". Keeping the waters of the Arcachon Bay unpolluted has been at the top of the agenda for all the residents of this area for many decades. They all pull together and fight like lions when the natural integrity of their beautiful jewel is threatened in any way. They are well aware of the fact that oysters only look tough superficially in their formidable shell fortresses, however, contain a most delicate and sensitive mollusks, which can suffer gravely, once pollutants inadvertently become part of their diet. Despite the genuine commitment to absolutely clean waters, the community of the Bay of Arcachon has had to fight a number of uphill battles against pollution for many decades.

From 1970 to 1972, an oyster gill disease killed most of the Portuguese oysters (Crassosstrea angulata) in the bay. The horror was complete, when this species disappeared completely in the following two years. Where this disease came from, or what caused it for that matter, is unknown to this day. It ended up wiping out most the Portuguese oysters in Europe, bringing the entire French oyster industry to the brink of collapse. Fortunately, a new oyster species, the hardy Pacific oyster (Crassostrea gigas), was introduced in France successfully soon thereafter.

In 1974, the remaining oysters were showing unusual shell deformities. The consuming public responded negatively to the ill-formed shells and turned its back on Arcachon oyster growers. As it turned out, a type of marine anti-fouling paint used on some boats contained a substance called "TBT" (Tributyltin) . Today, TBT is considered one of the most powerful environmental poisons.

Just when the marine ecology of the Arcachon Bay seemed to be returning back to normal, things got worse. The Pacific oyster refused to spawn despite seemingly perfect conditions. From 1977 up until 1981, hardly any oyster babies were found in the bay. As it turned out, TBT also had a lasting effect on the reproductive system of the oysters. Oyster growers suffered great economic consequences. Millions of dollars in revenue were lost.

In 1978, the tanker "Amoco Cadiz" lost 230,000 tons of crude oil. The Bay of Arcachon took a direct hit from this disastrous oil spill. Thousands of birds died, shellfish (including oysters) choked in the blanket of oil slime and many oyster growers went out of business.

Ultimately, the oyster industry of Arcachon almost collapsed completely. In fact, the entire oyster industry of France became unstable, as the Arcachon Bay not only produces lots of excellent oysters, it is also the principal French supplier of seed oysters for all of Europe. Countless oyster growers in the cooler climates of Europe, where the Pacific oyster only reproduces sporadically at best, are dependent on a seasonal supply of countless "oyster babies" from Arcachon.

Needless to say, these tragic circumstances in Arcachon had national implications for France, the largest producer of oysters (by far) in all of Europe. As early as 1982, France outlawed the use of marine paint containing TBT on vessels up to 25 meters (approx. 80 ft). In 1989, the European Union ("EU") followed the example France had set. Not long after France passed its TBT legislation, the Bay of Arcachon started to recover again - and along with it, the oyster business came back to life.

In 2003, Arcachon was hit once more by disaster. Slowly, the oil spill of the tanker "Prestige" moved into the bay. In the context of public safety, the French government imposed a short term moratorium on the sale of oysters from Arcachon. The bay ended up getting lucky that time around, as the damage caused by the oil spill turned out to be marginal. Simultaneously, the French government provided generous financial subsidies for the oyster growers of Arcachon.

As was briefly mentioned, the oyster industry of Arcachon is two-fold: growing oysters for the market and growing seed oysters ("Naissains") for oyster growers elsewhere in Europe. The later is a fascinating business, founded in a boatload of history and features a number of interesting techniques. It is discussed separately. The former, growing oysters for the consuming public, is also a big business in Arcachon. Approximatel 15,000 metric tons are produced annually. Oysters from Arcachon have been famous all over France for centuries.

Many growers of Arcachon also improve their oysters in a form of claire, which serves to cleanse the oysters of any impurities (mud, sand...) and keep them fresh. The oysters are placed in big basins filled with saltwater for a while. The water level in these claires is adjustable. It can be lowered, artificially inducing a "low tide" in essence. The oysters naturally respond by pulling shut. The powerful abductor muscle of an oyster functions in two ways. One part of the abductor muscle will rapidly pull the "lid" (the "right valve") down on the edge of bottom shell half (the 'left valve"). The other part of the abductor muscle keeps the shell fortress closed for an extended period of time. Contrary to popular belief, the abductor muscle does not "push" anything, it only "pulls" and 'holds". The springy ligament at the hinge of the oyster opens the oyster once the abductor muscle relaxes. Oystermen in Arcachon (and also in a number of other growing regions in and around France) "teach" the oysters to "forget" the natural rhythm of the tides and to stay shut longer by conditioning their abductor muscles. The artificial "low tide" can gradually be prolonged in these basins and the oysters get used to these "dry spells". When the time comes for the oysters to be shipped, they will have little trouble "keeping their mouths shut" and staying fresh and moist for many days - much to the delight of fish mongers and oyster lovers alike. This final conditioning phase is called "Trompage".

Of course, some Arcachon growers also offer "refined oysters", so called "Fines" and "Spéciales" which, similar to the famous Marennes-Oléron oysters, have received special care by being placed temporarily in nutritious "claires". Arcachon is also famous for excellent European oysters (Ostrea edulis). In these parts, the European oyster is called a "Gravette".


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Health advisory: There is a risk associated with consuming raw oysters or any raw animal protein. If you have chronic illness of the liver, stomach, or blood or have immune disorders, you are at greatest risk of illness from raw oysters and should eat oysters fully cooked. If you are unsure of your risk, you should consult your physician.

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© 2014 John W. McCabe