Unique Ecosystem - Marine Life
Currently, there are two types of hermatypic corals in the Oki Islands: nihon-awa-sango (Alveopora japonica) and amime-sango (orange Psammocora). Nihon-awa-sango is endemic to the waters surrounding Japan; it is distributed from Sagami Bay to the east coast of Kyushu in the waters of Kuroshio Current along the Pacific coast, and from Wakasa Bay to the west coast of Kyushu in the waters of Tsushima Warm Current in the Sea of Japan. It is considered this species adapted to warm regions because it is widely distributed in warm waters. The habitat ranges from rocky reefs at a depth of 15m to muddy shallow waters in inner bays, where large colonies may be formed. The coral forms a small colony with a diameter of around 10 cm and often forms a beautiful sphere. The habitat of the coral that has been confirmed is very limited, and the population is also very small; this is a highly valuable coral.