Sudd. 05/06/06; 5,700,000 ha; 07°34'N 030°39'E. Includes National Park and game reserves. One of the largest tropical wetlands in the world, located in South Sudan in the lower reaches of Bahr el Jebel, a section of the White Nile. The site is composed of various ecosystems, from open water and submerged vegetation to floating fringe vegetation, seasonally inundated woodland, rain-fed and river-fed grasslands, and floodplain scrubland. It is an important wintering ground for birds such as Pelecanus onocrotalus, Balearica pavonina, Ciconia ciconia and Chlidonias nigra, and home to some endemic fish, birds, mammal and plant species. The wetland serves as a filter that controls water quality and a sponge that stabilizes water flow. It is the major source of water for domestic, livestock, and wildlife use and an important source of fish. The socio-economic and cultural activities of local people are dependent on its annual floods and rains to regenerate floodplain grasses to feed their cattle, as they move from permanent settlements on the highlands to dry-season grazing in the intermediate lands and return to the highlands in May-June when the rainy season starts. Threats to the site include oil exploration - Sudd contains South Sudan's largest oil reserve - and the Jonglei Canal Project, which is currently on hold, but would reduce wet and dry season flows by 20% and 10% respectively, thus impacting the wetland's ecology and consequently its inhabitants. Ramsar site no. 1622. Most recent RIS information: 2006.