Coastal Area 12207 Inner Tokyo Bay

Basic Information References

Reason(s) for selection Criteria

Characteristics References

These waters consist of the tidal mud flats and shallows of Tokyo Bay that include Sanbanze, the Yatsu tidal mud flats, Kasai, Tokyo Port Wild Bird Park, Central Seaside Park, Morigasaki, and the mouth of the Tama River. While in the past Tokyo Bay was home to expansive river mouth and tidal mud flats zones, today only a few spots remain, and these waters include those few remaining tidal mud flats and river mouth ecosystems. Numerous species of birds, in large populations, visit Sanbanze during the spring and fall migrations and winter there. At least 1% of the minimum estimated population has been recorded there for dunlin, and at least 0.25% for Eurasian oystercatcher, black-bellied plover, lesser sand plover, grey-tailed tattler, ruddy turnstone, and sanderling. In addition, Japanese littleneck clams and other bivalves live there along with Stenothyra edogawaensis, playing important roles in the purification functions of Tokyo Bay. Numerous species of birds, in large populations, visit the Yatsu tidal mud flats too during the spring and fall migrations and winter there. At least 1% of the minimum estimated population has been recorded there for dunlin, and at least 0.25% for black-winged stilt, black-bellied plover, Kentish plover, lesser sand plover, bar-tailed godwit, Numenius phaeopus, grey-tailed tattler, ruddy turnstone, and sanderling. Far Eastern curlew and common redshank also have been recorded. The river mouth areas deep in Tokyo Bay are the northern limit of mudskipper habitat. While the Edo River sluiceway is artificial, it includes sandy and muddy tidal mud flats as well as some saltwater marshlands of common reed and is abundant in creatures that live in enclosed tidal mud flats, such as Cyclina sinensis and others. Relatively numerous species of birds, in large populations, visit Tokyo Port Wild Bird Park, Central Seaside Park, and Morigasaki as well during the migration seasons of spring and fall, and the black-winged stilt and common redshank have been recorded here. The mouth of the Tama River constitutes the only waters in Tokyo Bay where river-mouth tidal mud flats that contain large groupings of saltwater marshlands remain, and a variety of biota, including 56 benthic species, have been confirmed to live there (Of these 56 benthic species, 16 are rare or endangered). The same river mouth area could form one habitat in the so-called Tokyo Bay tidal mud flats network, as an important node. It also sees relatively numerous species of birds, in large populations, during the migration seasons of spring and fall, and the black-winged stilt has been recorded here. In addition, oyster reefs are found here and there, providing places for a wide range of creatures to live (Ministry of the Environment, 2001; Yuzuhara et al, 2013; Furota, 2007).