Coastal Area 15402 Ariake Sea coast

Basic Information References

Reason(s) for selection Criteria

Characteristics References

These are the coastal waters of the Ariake Sea, including those from the mouth of the Chikugo River to the mouth of the Yabe River, the Higashiyoka Coast, the waters from the mouth of the Rokkaku River to the mouth of the Shioda River, the Kajima Coast, the mouth of the Tagori River, the Arao Coast, the mouths of the Kikuchi, Shirakawa, and Midori rivers, and others. Deep in the Ariake Sea are expansive saltwater marshlands and tidal mud flats that are habitat for the bluespotted mud hopper, Octopus minor, Scapharca globosa ursus, pen shell, and others, including 23 endemic species and 40 or more quasi-endemic species. Oyster reefs form in these waters. From the mouth of the Chikugo River to the mouth of the Yabe River are habitats where continental relict inland water species not seen in other regions of Japan, including Cleistostoma dilatatum, Ilyoplax deschampsi, Salinator takii, and others, are prolific. The tidal zone of the Chikugo River is a spawning ground for Salanx ariakensis, Neosalanx reganius, and Japanese Grenadier Anchovy, and the coast of the Ariake Sea is a spawning ground for roughskin sculpin. The Higashiyoka Coast is Japan's largest habitat for Suaeda Japonica and a place where large numbers of species and populations of snipe and plover winter and visit during the spring and fall migrations, and at least 1% of the minimum estimated population of black-bellied plover, dunlin, and Eurasian curlew has been recorded here, as has at least 0.25% of the minimum estimated population of Kentish plover, lesser sand plover, greenshank, Terek sandpiper, and grey-tailed tattler. Other species recorded here are spotted greenshank, little curlew, common redshank, Far Eastern curlew, and common shellduck. The Kajima Coast too is a place where relatively large numbers of species and populations of snipe and plover winter and visit during the spring and fall migrations, and it is visited by common shellduck and Saunders' gull as well (Ministry of the Environment, 2001; BirdLife International, 2012). Euspira fortunei, Tegillarca granosa, Serratina capsoides, Camptandrium sexdentatum and other rare species are distributed at the mouth of the Tagori River. The waters from the mouth of the Rokkaku River to the mouth of the Shioda River are a habitat where Angustassiminea kyushuensis proliferate to an unparalleled degree, and the rare species Cerithidea ornata, Cerithidea largillierti, and Melampus sincaporensis proliferate here as well. The Arao coast is a place where relatively large numbers of species and populations of snipe and plover winter and visit during the spring and fall migrations. The mouths of the Shirakawa and Midori rivers also see relatively large numbers of species and populations of snipe and plover wintering and visiting during the spring and fall migrations. Endemic endangered species proliferate in the saltwater marshlands here. In the muddy tidal mud flats Estellarca olivacea are prolific. This also is habitat to Salanx ariakensis and Neosalanx reganius (Ministry of the Environment, 2001). It is known that small Japanese squid, particularly Loliolus (Nipponololig) beka, are distributed in Japan only in the central Seto Inland Sea and the Ariake Sea. They are distributed widely in the shallow waters in the inner reaches of the Ariake Sea, where it is thought that they spend their entire life cycle, including spawning grounds (Natsukari, 1998). The Ariake Sea's finless porpoise and many of its fish move widely around the Ariake Sea during their life cycles (Takita and Yamaguchi, 2009).