Topography and hydrology
Can Gio Biosphere Reserve is located in Can Gio district (previously Duyen Hai district), in the coastal zone of Ho Chi Minh City. The area is situated in a recently formed estuary complex of tidal flats, where the Vam Co, Saigon and Dong Nai rivers discharge into the sea. The topography of Can Gio is low-lying and dynamic. The site is divided by a network of canals and rivers.
The major habitat types found at Can Gio are plantation mangrove, of which there is about 20,000 ha, and naturally regenerating mangrove, of which there is about 7,000 ha. The principal mangrove species used for replantation has been Rhizophora apiculata, although R. mucronata has also been used in smaller amounts. In addition to the mangroves, the site also supports seagrass beds dominated by Halophyla sp., Halodule sp. and Thalassia sp.
A total of 18 mollusc, 27 crustacean, 45 fish and three amphibian species have been recorded at the site. There are anecdotal reports of local farmers shooting an Estuarine Crocodile Crocodylus porosus at the site in around 1990, although there have been no records since then. Also, Dugong has been reported to occur seasonally in seagrass beds at the site, although these reports have not been confirmed.
The intertidal mudflats and sandbanks at the biosphere reserve are an important habitat for migratory shorebirds. ADB (1999) reports that Wood Sandpiper Tringa glareola, Common Redshank T. totanus, Common Sandpiper Actitis hypoleucos, Grey Plover Pluvialis squatarola, Lesser Sand Plover Charadrius mongolus and Black-winged Stilt Himantopus himantopus occur at the site. In addition, several globally threatened and near-threatened waterbird species have been recorded at the IBA, including Spotted Greenshank Tringa guttifer, Asian Dowitcher Limnodromus semipalmatus, Spot-billed Pelican Pelecanus philippensis and Painted Stork Mycteria leucocephala. Consequently, Can Gio qualifies as an Important Bird Area.
Other documented values
The mangrove forest at Can Gio performs many valuable ecological functions, including coastal stabilisation, and protection against coastal erosion, oil spills and storm surges. The mangrove forest is a source of fuelwood and construction materials.
Being close to Ho Chi Minh City, Can Gio Biosphere Reserve has great potential as a site for tourism, public education, scientific research and training. Already, the site receives a large number of visitors from Ho Chi Minh City. Can Gio could also serve as a demonstration site for mangrove afforestation projects elsewhere in Vietnam.