The Ariake Sea is the largest bay surrounded by the prefectures of Fukuoka, Saga, Nagasaki, and Kumamoto. The bay, the deepest point of which is no more than 50 meters deep, is shallow to a considerable distance from the shore. The water depth differs largely by the ebb and tide. The range of a spring tide is over 4 meters. Laver cultivation has developed using this spring range. At low tide emerges the tideland, which is the habitat of rare species that cannot be found anywhere else such as mudskippers, pen shells, warasubo (a species of eel goby), and fiddler crabs. The Ariake Sea has been providing people with food since the ancient times. A lot of shell mounds have been discovered near the coastline, from which clams, arch shells, and fish bones of Japanese seaperch and others were excavated. Living aquatic resources in the Ariake Sea has supported people’s diet.