On the territory, water area and the vicinity of the nature reserve established residence for more than 205 species of birds. Breeds of not less than 54 species, including 11 - in open grassy and about 17- in rocky habitats. Not less than 33 species are wintered in reserve.
About 112 species are migrating to. Ornithofauna of Opuk includes 32 rare species registered in the Red book of Ukraine. Among them – shag, ruddy shelduck, saker, рeregrine, сrane, bustard, little bustard, stone curlew, kentish plover, rose-coloured starling, grey shrike, black-headed bunting and others.
Among the mammals are fox, european (brown) hare, rare animals: great jerboa, Rhinolophus ferrumequinum, Pipistrellus kuhlii, Mustela eversmanni. In the Black sea area of the species listed in the Red book of Ukraine, can be found: Hippocampus guttulatus microstephanus, Callionymus pusillus, Salmo trutta labrax, Phocoena phocoena relicta, bottlenose dolphin, as well as seal.
The territory of the Opuk included in the list of IBA territories, important for the conservation of populations of birds within Europe.
"Аquatic-coastal complex of Cape Opuk", an area of 775 ha, entered in the list of wetlands of international importance (Ramsar convention) in 2004.