St Helena has excellent and well preserved coral ecosystems, which are very diverse and contain many endemic and non-endemic fish species.
The following 10 fish are found only on the island of Saint Helena:
- Bastard cavalley pilot (Stegastes sanctaehelenae)
- Bastard fivefinger (Chromis sanctaehelenae)
- Deepwater jack (Pontinus nigropunctatus)
- Deepwater gurnard (Scorpaena mellissii)
- Deepwater greenfish (Holanthias fronticinctus)
- Silver eel (Ariosoma mellissii)
- Greenfish (Thalassoma sanctaehelenae)
- Skulpin (Physiculus helenaenis)
- Springer’s blenny (Scartella springeri)
- St Helena dragonet (Callionymus santaehelenae)
- St Helena offers a unique opportunity to view cetaceans using small boats. Pan-tropical spotted dolphins (Stenella attenuata) are the most numerous species followed by bottlenose dolphins (Tursiops truncatus) and rough-toothed dolphins (Steno bredanensis).
- Humpback whales (Megaptera novaeangliae) have been sighted but interviews with local fishermen suggest that this species regularly occurs in the waters around St Helena in small numbers during the austral winter.