The oyster is a bivalve mollusc of the family Ostreidae. It lives only in saltwater or brackish water in all the seas of the world and in its natural state on bedrock. The most present in France is Magallana gigas, cyclic hermaphrodite.
From one year of reproduction to another, it is either male or female. Above 10 degrees in the water it prepares its gametes and the breeding period can start from 18 degrees in the water. The released eggs will find the spermatozoa and be deposited at random on the seabed. It is this peculiarity that has been exploited for a long time in the Arcachon basin, almost closed, the capture is therefore easier.
In the spring, the oyster farmers will deposit in their concessions sensors to recover spat. These sensors come in different ways. The limed canal tile is the oldest method, gradually replaced by plastic tubes or cups on tubes. This catchment work is a very big activity locally, since 60 to 70% of the spat will be resold in the parks everywhere in France and even in Europe. A Norman oyster that you taste in Trouville is definitely born in Gironde. The oyster develops in salty or brackish water but its breeding and taste quality depends essentially on what it can find in the water. The Gulf Stream, which licks off the Atlantic coast, provides Phytoplankton and ideal temperatures for mollusc development. We have the best terroir in the world for growing oysters.