Olive sea snake
The reptiles found in the tropical waters of the Great Barrier Reef fall into three major groups:
- marine turtles
- sea snakes
Marine turtles are commonly seen in some Reef waters. They nest on many Reef islands and some parts of the coast. Six of the world's seven species of marine turtle are found on the Reef. All are regarded as endangered.
About 16 species of sea snake are found in the waters of the Great Barrier Reef. They are among the most venomous snakes in the world, possessing some of the most potent toxins known. Most are extremely curious and will approach divers. However, except for the breeding season when they become territorial, sea snakes are not generally aggressive.
Estuarine crocodiles found in the Great Barrier Reef region are considered as temporary migrants from coastal river systems.