[2] The park provides habitat for 53 mammal species, including the endangered Sumatran tiger, Sumatran elephant, Malayan tapir, agile gibbon and siamang, as well as the vulnerable Sunda clouded leopard, marbled cat, flat-headed cat, sun bear and southern pig-tailed macaque.

Other threatened birds in the park include the Storm's stork, white-winged duck, Nordmann's greenshank and Far Eastern curlew.

It is under threat from small scale illegal logging,[2] 15 meters abrasion a year and coastal fish ponds activities.

[3] Together with the neighboring Berbak National Park in the province of Jambi, Sembilang is acknowledged as a part of UNESCO World Network of Biosphere Reserves in 2018.

[5] On January 15, 2020, the Jakarta Post announced that an uninhabited island in the park, Betet Island is now submerged at 1 meter below sea level as a result of climate change.