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Coastal Area 12205 Adjacent waters of Obitsu River mouth tidal mud flats

Basic Information A separate window opensReferences

Relevant municipalities Sodegaura, Kisarazu, Chiba Prefecture
Area (km2) 52

Reason(s) for selection A separate window opensCriteria

Selected due to high levels for the criteria 1, 2, 7 and 8, and selected by MARXAN software.

Characteristics A separate window opensReferences

These are the waters in the vicinity of the mouth of the Obitsu River and the Banzu tidal mud flats. These waters include the largest tidal mud flats in Tokyo Bay, and the natural formation is very well preserved along the expansive saltwater marshlands at the river's mouth. Cerithidea rhizophorarum, Laternula marilina, Clistocoeloma sinensis, mudflat crab, Japanese littleneck clam, Mactra veneriformis, Umbonium moniliferum, and others live here. At the mouth grows Zostera japonica, and its insect population includes one of the few habitats of Drypta fulveola. The expansive marshlands include common reed, Carex scabrifolia, and others. Numerous species of birds, in large populations, visit during the spring and fall migrations and winter here. At least 1% of the minimum estimated population has been recorded here for Kentish plover, grey-tailed tattler, and dunlin, and at least 0.25% for lesser sand plover, Numenius phaeopus, ruddy turnstone, sanderling, and dunlin. Also recorded here have been rock sandpiper, black-winged stilt, common redshank, Far Eastern curlew, and Oriental pratincole (Ministry of the Environment, 2001).

Environment / Habitat infromation A separate window opensData source

Tidal mud flats (km2) 28.7
Moba (seaweed bed) (km2) 2.1
Coral reef coverage (km2)
Natural coast (km) 5.8
Rate of natural coast (%) 6.3
Sand bank / submerged sand bank
Other habitats

Species information (*) A separate window opensData source

Criteria 1
Pinnixa haematosticta
<Bivalva, Gastropoda>
Stenothyra edogawensis
Cyclina sinensis
Angustassiminea castanea
Solen strictus
Corbicula japonica
Angustassiminea yoshidayukioi
<Vascular Plants>
Zostera caulescens
Criteria 2
Neophocaena phocaenoides (Fineless porpoise)
Larus crassirostris (Black-tailed Gull)
Larus crassirostris (Black-tailed Gull)[Br/Ne]
Phalacrocorax carbo (Great Cormorant)[Br/Ne]
Sterna albifrons (Little Tern)
Sterna albifrons (Little Tern)[Br/Ne]
Charadrius dubius (Little Ringed Plover)[Br/Ne]
Charadrius alexandrinus (Kentish Plover)[Br/Ne]
Larus argentatus (European Herring Gull)
Amphioctopus fangsiao (Ocellated octopus)
Octopus vulgaris (Common octopus)
Loligo bleekeri (Spear squid)
Criteria 3
Sterna albifrons (Little Tern)
Gymnogobius macrognathos
Pinnixa haematosticta
Ilyoplax pusilla
<Bivalva, Gastropoda>
Cyclina sinensis
Laguncula pulchella
Littorina brevicula
Criteria 7
Macrophthalmus abbreviatus
Ocypode stimpsoni
<Bivalva, Gastropoda>
Umbonium moniliferum
Cerithideopsilla cingulata
Corbicula japonica
<Vascular Plants>
Zostera marina (Eel grass)
Aster tripolium (Sea aster)
Zostera japonica

* This is the species list of which meet the criteria. In that matter, this list does not include all species that inhabit the individual area.
Abbreviation in the information is as follows.
[Br/Ne] : Adjacent water of breeding area or nesting site
[Sp] : spawning area
[Ad] : species not used for analysis but add to the list because inhabit information was collected later
[Ex] : species used for analysis but considered to be possibly extinct in the EBSA region (area)
No mark : data of species distribution


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