Six of the world’s seven marine turtle species have been recorded in the Great Barrier Reef.
The six include the green, hawksbill, loggerhead, flatback, leatherback and olive ridley turtles. They use different parts of the region for feeding, migration and nesting, so the reef supports several stages of marine-turtle life rather than serving only as a feeding ground.
The flatback turtle is especially associated with northern Australian waters because it nests only in Australia and nearby coastal areas. Green turtles are common reef herbivores and graze on seagrass and algae, while hawksbills often feed around coral reefs. Loggerheads forage over the seabed and nest on sandy beaches.
The seventh living marine turtle species is the Kemp’s ridley, which is mainly associated with the Gulf of Mexico and nearby waters. That is why “six of seven” is the established Great Barrier Reef figure. Marine turtles still face threats from habitat loss, bycatch, pollution and climate-related changes to nesting beaches.