As the result of the several discoveries and the development of new techniquer and equipment, the importance of the shellfish industry has increased since 1950. One shellfish, the oyster has been cultivated in great numbers by means of the new technology. Marine biologists discovered that by using chemicals and raising the water temperature,they could induce oysters to lay eggs not only in the summer but also in the fall,winter and spring.They also succeeded in breeding new strains of oysters that were resistant to diseases and grew faster and larger.In addition, the cultivated oysters taste better.