The cupped Pacific oyster, Crassostrea gigas, has been the most widely farmed species of oyster since the 1970s. Originally from Japan, it was introduced across the world to replace stocks depleted by overharvesting or decimated by disease, such as those of the European flat oyster, Ostrea edulis, which declined from the 1920s.
Several different techniques are used to farm oysters, depending on the place, the species and local traditions. Oysters are cultivated on the foreshore (the part of the coastline between high- and low-water marks), in ponds or in the open sea. They may be raised off the seabed, placed in bags laid flat on tables. With suspended culture, they are attached to ropes hanging from a table or a floating system, and are permanently immersed. In the open sea, oysters are grown with the long-line method, with cages suspended from cables or rafts.
Oysters are refined in large salt ponds, called claires, where the water is less saline but rich in plankton. It is here that oysters obtain their flavour and colour. During the finishing stage, oysters are placed in water of impeccable quality, where they are washed and sorted. Depending on the species and breeding conditions, it takes two to three years for an oyster to reach a marketable size.
© Shutterstock / 135pixels - Oyster farming on tables, at low tide