In the eastern part of the region there is a 45.000 square hectares Sembilang Wildlife Reserve. Sembilang National Park was setup in 2003 in southeastern Sumatra. Over 350,000 hectares of peat swamp, freshwater swamp and mangroves, the park is host to a few critically endangered Sumatran tigers.
Sembilang is such a paradise for various kinds of protected birds like lesser adjutant stork, milky stork, spot billed pelican, wild duck, eagle, hornbill, etc. There are also two kinds of Sumatra crocodile, i.e. crocodilus porosus and tomistoma slegeli. In Sembilang river there also lives irrawadi dolphins and humpback dolphins.
Sembilang National Park with a total area of approx. 206 ha, is also one of the largest mangrove forests in the Indo-Malayan region and one of the widest mangrove zones in the world, in some areas extending inland up to 35 km. The mangroves provide feeding, nesting and roosting areas for many globally threatened species of wildlife, and are one of the most important stopover sites for migratory waders in the East Area Flyway (up to one million birds). The shallow mangrove zone in the area is highly productive, and more than 8.000 fishermen and their families find full time employment in the coastal fisheries.