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Location Japan, Chiba
Central coordinates 139o 54.00' East  35o 24.00' North
IBA criteria A4i
Area 2,400 ha
Altitude 0 - 5m
Year of IBA assessment 2004

Wild Bird Society of Japan

Site description Banzu tidal flat consists of an estuary delta (43 ha) which lies on the northwestern side of the tide embankment on the right bank of the Obitsugawa river, and the Maehama tidal flat (1,400 ha) which lies ahead. The delta is salty marsh which vegetates mainly Phragmites australis, and through which a waterway influenced by both salty and fresh water runs. A part of the delta has Pleioblastus chino Makino community, Celtis sinensis japonica grove, a planted Pinus thunbergii grove and an artificial pond. Maehama is one of the largest natural sandy tidal flat in Japan, where the tide ebbs as far as 1.5 to 2 km offshore during spring tide. It has the tidal range of 2 m and the gradient of approximately 1/1000. Futtsu tidal flat is a sandy tidal flat located on the northeastern side of the Futtsumisaki cape. It has an algal field of Zostera marina L., and its eastern area is used for shellfish gathering. There is a promenade in the Pinus thunbergii forest. Its beach is well used for leisure activities.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Greater Scaup Aythya marila winter  2004  present  A4i  Least Concern 
Charadrius alexandrinus resident  2004  present  A4i  Not Recognised 
Grey-tailed Tattler Tringa brevipes passage  2004  present  A4i  Near Threatened 
Sanderling Calidris alba winter  2004  present  A4i  Least Concern 

IBA Monitoring

2010 low not assessed negligible
Poor - based on little, or potentially unreliable/unrepresentative, data

Human intrusions and disturbance recreational activities likely in long term (beyond 4 years) some of area/population (10-49%) no or imperceptible deterioration low

Little/none of site covered (<10%)  Unknown  Unknown  negligible 


IUCN habitat Habitat detail Extent (% of site)
Wetlands (inland)   -

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Banzu and Futtsu tidal flat. Downloaded from on 21/10/2016

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