Cat Ba is an island of approximately 140 sq.km in Halong Bay, Northern Vietnam, is the largest island in the Bay and approximately half of its area is covered by a National Park, which is home to the highly endangered Cat Ba langur. This golden-headed langur is rarely seen, as fewer than 100 specimens are thought to survive in the wild, although it is the subject of a well-organized conservation programme. The Park covers both land and marine areas and has a high biodiversity, although it is at risk from too rapid an increase in tourism. Other mammals in the Park include civet cats and oriental giant squirrels. Cat Ba itself is attractively situated around a bay teeming with small boats, many of which belong to pearl or shrimp farmers, and can become very busy at weekends and during public holidays. The promenade has illuminations and a large fountain which only plays after dark; it is backed by a strip of cheap hotels and bars, but dominated by the wooded limestone hills behind. The island is a national park of Vietnam and was recognized by UNESCO in December 2004 as a Biosphere reserve of the world. 

The National Park and Biodiversity Conservation

Cat Ba National Park was established in 1986. After a re-arrangement of the park boundaries in 2006, the park now comprises of 109 square km of land area and an additional 52 square km of inshore waters and mangrove covered tidal zones. Cat Ba National Park was Vietnam’s first national park to include both terrestrial and marine ecosystems. Cat Ba Island, its national park and the surrounding area are nationally and internationally recognized for their importance to biodiversity conservation, exemplified through the recognition of the Cat Ba Archipelago as a UNESCO Man and Biosphere Reserve, in 2004. This is not only because the area has a high number of different ecosystem and habitat types, but also because it possesses a great variety of plant and animal species, many of which, like the Cat Ba langur, are now rare and endangered. About 1400 vascular plants, including 23 Endangered and Critically Endangered species (Red Data Book of Vietnam; IUCN Red List) have so far been recorded. Large and partly endangered mammals include the Cat Ba langur, the Southern Serow (Naemorhaedus sumatraensis), Rhesus macaque (Macaca mulatta), Leopard Cat (Prionailurus bengalensis), black giant squirrel (Ratufa bicolor), and civet cats (Viverricula indica, Paradoxurus hermaphroditus). The cave, land snail and butterfly fauna is rich including the most northerly cave-adapted crab species, plus four species of true cave snails. The region is considered a hotspot for land snail diversity and might also be conserving a considerable number of bat species including rare ones.