Many people are surprised to learn there are only a few species of oysters. The European oyster (Ostrea edulis) is found along the coasts of France, England and Ireland. Well-known varieties include the Belon.
The Kumamoto oyster (Crassostrea sikamea) is a successfully cultivated import from Japan that was brought to the Northwest in the 1940s.
Olympia Oysters (Ostrea conchaphila) are found from Baja California to Alaska and the only native species found in Washington state.
Pacific Oysters (Crassostrea gigas), found throughout the West Coast, are native to Korea, Japan and China. And because they reproduce and grow fast, they are highly cultivated and produced commercially.
Eastern Oysters (Crassostrea virginica) range from the cold waters of Canada throughout the mid-Atlantic to the southern coastal states and Gulf of Mexico.
For the connoisseur, though, species matters less than location. Oysters get their distinctive flavors and delicate textures more from their environment than any other factor. The difference in flavor depends on the water temperature, salinity levels, the tides and the mix of nutrients they feed on. Oysters from colder waters are plump with a sweeter taste and delicate texture. Oysters from saltier waters have a cleaner, sharper finish. Oysters from warmer, brackish waters are meaty and have richer flavor.
Consider this: Each of the oysters found up and down the East Coast and across the gulf are the same Eastern, or American, species. From the highly prized Malpeques from Prince Edward Island, to the creamy Wellfleets from Connecticut and Blue Points from Long Island; to the Chincoteagues, Kents and Patuxent River oysters from the Chesapeake Bay; to the Bon Secours from Mobile Bay. Each variety is quite distinct.
-- Russell Cronkhite