The conditions in the shallow sea, the intensity in the ebb and flow of the tide, and the geographical location where seawater and freshwater mix are suitable for growing nori. The Ariake Sea in Kyushu, which meets all these requirements, produces about 40% of Japan’s seaweed. Production areas developed in Saga, Fukuoka, Kumamoto and Nagasaki prefectures that surround the Ariake Sea. In 1943, Kumamoto Prefecture successfully experimented artificial seaweed seeding. The production has been considerably increased by the use of new techniques and modern technologies.