The outstanding diversity of habitats, terrestrial, wetland, coastal and aquatic, supports a wide variety of animal species, some at the northern and many at the southern limit of their range.
The fringing coral reefs are among the southernmost in the world. The lakes, swamps and shallows comprise the most productive estuarine prawn nursery and marine nursery of the South African coast.
There are 97 species of terrestrial mammals in the Park including the internationally threatened (reintroduced) black rhinoceros Diceros bicornis minor (CR: 13 in the Eastern Shores and 95 in the adjoining Mkusi Game Reserve), and 150 white rhinoceros Ceratotherium simum. The Park has the largest single populations in South Africa of hippopotamus Hippopotamus amphibius (VU: about 700), the endemic red duiker Cephalophus natalensis natalensis and southern reedbuck Redunca arudinum. It also has the largest publicly protected populations in KwaZulu-Natal of the endemic Tonga red squirrel Paraxerus palliatus tongensis, cane rat Thryonomys swinderianus and four-toed elephant shrew Petrodromus tetradactylus, thicktailed bushbaby Otolemur crassicaudatus, samango monkey Cercopithecus mitis, side-striped jackal Canis adustus, banded mongoose Mungus mungo, brown hyaena, Hyaena brunnea and bushbuck Tragelaphus scriptus, The cheetah Acinonyx jubatus (VU) was reintroduced in 2003 and the African wild dog Cuon alpinus (CR) was reintroduced to neighboring Mkuzi Reserve in 2005.