IV.

Distribution

Oysters are found throughout the world. They usually form large beds, which extend in warm waters from the tidal zone to a depth of up to 30 m (100 ft). Beds of American bluepoint oysters are found along the eastern coast of the continent. Chesapeake Bay is the largest oyster-producing body of water in the world, although many of its oyster beds have been depleted through overfishing or pollution. Large beds of edible oysters also exist in Japan and Australia. The native American Olympia oyster, which is much smaller and has a thinner shell than other edible species, is found on the west coast of North America.

Oyster culture is practiced in many countries. Young oysters, called seed oysters, are placed on suitable bottoms provided with artificial collectors, such as tile or shells. The most elaborate system of oyster cultivation is practiced in Japan, France, and the Netherlands.

Scientific classification: Oysters make up the family Ostreidae of the order Ostreoida. The European oyster is classified as Ostrea edulis, the Olympia oyster as Ostrea lurida, and the American bluepoint oyster as Crassostrea virginica. Pearl oysters belong to the family Pteriidae of the order Pterioida.