Cat Ba Archipelago
Location:	20°42'-20°54'N, 106°52'-107°07'E; off the northeast coast of Vietnam in Halong Bay, about 30 km east of Hal Phong City and Port.
Area:	34,500 ha.
Altitude:	0-331m.
Biogeographical Province:	4.6.1.
Wetland type:	03, 05, 07, 12, 15 & 21.
Description of site:	Cat Ba Archipelago consists of one main island and 366 smaller islands. The archipelago possesses a great variety of landscapes and diversity of ecosystems including offshore coral reefs, sandy beaches (3,580 ha), mangrove forests (2,300 ha), freshwater swamp forests, small freshwater lakes and forested hills. There are many areas of spectacular scenery, especially in the "sugar loaf" limestone karst areas on the main.island where there are numerous waterfalls, caves and grottos. The principal streams on the main island are the Thung Luong, Treo Corn, Hoi Trung Trang and Viet Hai. There are several small lakes and ponds in the hills, the largest of which is Ech Lake, a permanent lake with a surface area of 3 ha and a depth of about 50m. Much of the main island is between 50m and 200m above sea level; the highest peaks rise to 33lm (Cao Vong) and 302m (Hien Hoa), and only 10% of the island is below 50m in elevation. However, some places in the interior of the main island, such as Ang Tom in Viet Hal Village, are below sea level. The principal beaches are at Cai Vieng, Hong Xoai Lon and Hon Xoai Be. The tidal range is 3.3-3.9m (exceptionally 4.0m). The salinity of the surrounding waters fluctuates seasonally, ranging from 31.11 p.p.t. in the dry season (December to March) to 9.30 p.p.t. in the wet season (June to September). Most of the streams are seasonal, flowing only after tropical rain storms, but some of the streams in the higher valleys are perennial or almost so. Most of the rain water flows into caves and grottos, and follows underground streams to the sea. There is often, therefore, a severe shortage of fresh water during the dry season.
Climatic conditions:	Tropical monsoonal climate with pronounced wet and dry seasons. The average annual rainfall is 1,700-1,800 mm, the mean annual temperature at sea level 25-28°C, and the mean relative humidity 85%. The rainy season lasts from May to September, the heaviest rainfall occurring in July and August. The average temperature at this season is 30°C; the prevailing wind is southeasterly, and typhoons and tropical storms are frequent. The dry or cold season lasts from November to March. The temperature normally varies between 16°C and 19°C, although it occasionally drops to below 10°C. There is often some drizzle in the months of February, March and April.
Principal vegetation:	There are three main types of vegetation in the archipelago: tropical evergreen forest on the hills, freshwater swamp forest at the foot of the hills, and coastal mangrove forest. The hill forests include species such as Spondias lakonensis, Milius flipes, Indospermum sp, Pometia pinnata, Euphorbia sp, Carralli lancaefolia and Dimerocarpus brenieri, with trees up to 20-30m in height. Species of Urticaceae and Orchidaceae are dominant in the lowest stratum of the forest. On the mountain summits, the vegetation is drought resistant and stunted due to the strong winds, the trees not exceeding 5m in height. In some places Sasa japonica is dominant. Common species in the swamp and foothill forests include Dracontomelum duperreanum, Aglaia gigantea, Duabanga sonneratioides, Lagerstroemia balansea, Pterospermum sp, Cinnamomum spp, Caryodaphnopsis tonkinensis and Peltaphorum tonkinensis. These species, which grow to heights of about 20m, dominate the upper stratum of the forest. A lower stratum with trees up to l2m in height includes Engelhardtia spicata, Gironniera subaequalis and Garcinia sp, while a third stratum with trees up to 8m in height includes Aiphonsea spp and Ardisia tonkinensis. The main island has over 2,300 ha of mangrove forest consisting of Rhizophora mucronata, Bruguiera gymnorhiza, Kandelia candel and Aegiceras mafus. The trees are, however, only 2-3m in height because of the cold winters, low concentrations of silt and over-exploitation. In total, 620 species of plants have been recorded in the archipelago.
Land tenure:	Public ownership.
Conservation measures taken:	In April 1986, the Government of Vietnam declared a large part of the main island and the adjacent waters as a National Park. The total area of 26,300 ha includes 17,300 ha of the main island and 9,000 ha of the adjacent inshore waters. The objectives of the National Park are: (a) to preserve the natural ecosystems and genetic resources of this tropical island; (b) to preserve the cultural and historical features of the island; (c) to restore the native fauna and flora through replanting, re-introductions and habitat improvement; (d) to promote outdoor recreation and environmental education for the general public in collaboration with the tourist industry; and (e) to promote scientific research relevant to the management of the park.
Conservation measures proposed:
Land use:	The principal activities of the local inhabitants are forest exploitation, agriculture and fishing. In 1983, the population of the main island was 7,751. Many of these immigrated from nearby coastal provinces in recent years and have settled mainly in the south of the island. The principal crops are rice, cassava and fruits.
Possible changes in land use:
Disturbances and threats:	Shifting agriculture, over-exploitation of the forest resources for firewood and construction materials, and the demand for grazing land for domestic animals have resulted in widespread deforestation and destruction of the natural vegetation. This in turn has had a detrimental effect on fish production and water supply. The park authorities are currently promoting rural planning to solve these problems.
Economic and social values:	Economic and social values: The forests are vital in maintaining the water regime for the whole area; they contain important genetic resources and supply raw materials to the food chain of aquatic animals (fishes, shrimps, bivalves and arthropods). The forests also provide pit props for mining areas in neighbouring Quang Ninh Province. The fishery is important not only for the local people but also for the population of the adjacent mainland (Hai Phong). About 350 tons of fish were landed in 1983. To date, 17 sites containing the traces of primitive humans have been located on the main island. Stone tools and bones found at the sites indicate that primitive man was living in the caves and grottos on the island between 6,000 and 7,000 years ago. Cal Beo Cave, about 1.5 km southeast of Cat Ba Town, has been studied most intensively. The cave was first discovered by a French archaeologist in 1938. The National Institute of Archaeology surveyed the cave some years later, and in 1983 the National Institute of Historical Museums and the Historical Museum of Hai Phong continued the research.
Fauna:	The fauna of the archipelago has not as yet been studied in detail. However, preliminary surveys have revealed that the fauna is distinctive, with unique elements adapted to the island conditions. One such endemic form is a subspecies of Francois Leaf Monkey Presbytis francoisi poliocephalus. Other mammals known to occur on the island include Macaca mulana, M. nemestrina, M. artoides, Capricornis sumatrensis, Cervus unicolor, Munijacus muntjak, Lutra lutra, Panthera pardus, Felis bengalensis, Viverra zibetha, Viverricula malaccensis, Ratufa bicolor, Callosciurus erythraeus, Tamiops swinhoe, three species of Rattus, Hystrix hodgsoni, Atherurus macrourus, Rhizomys sumatrensis and Hipposideros larvasus (four subspecies). Seals (Pinnipedia) and dolphins (Delphinidae) occur in the surrounding seas. The islands lie on a major migration route for many species of waterfowl. The beaches and mangrove forests provide feeding and roosting sites for large numbers of birds during the migration seasons, including several species of ducks and geese and many shorebirds. Resident species and summer visitors include Tachybaptus ruficollis, Phalacrocorax carbo, Anas poecilorhyncha, Amaurornis phoenicurus, Gallicrex cinerea and Hydrophasianus chirurgus. Forest birds include the hornbill Anthracoceros albirostris, a very rare species in northern Vietnam. Reptiles include Gekko gekko, Python sp, Embrystoma sp and the sea turtle Eretmochelys imbricata. Some 200 species of fishes, 500 species of molluscs and 400 species of arthropods have been listed for the islands.
Special floral values:	The forests contain many very interesting plant species including a subtropical plant Podocarpus fleuryi which occurs in a 570 ha patch of primary forest on the east side of the main island.
Research and facilities:	Local scientists have conducted preliminary surveys of the fauna and flora, and a considerable amount of archaeological research has been carried out.
References:	IUCN (in prep).
Criteria for inclusion:	1b. 1c, 2b, 2d.
Source:	Le Dien Duc.