Green turtles are found swimming and feeding in tropical and subtropical waters around the world. Their largest nesting areas are Tortuguero in Costa Rica and Raine Island in the Great Barrier Reef, Australia. Green turtles are popular worldwide as a food source. In fact they are named not for their body colouration but due to their green fat and muscles, a result of their seagrass diet. Their popularity as a source of protein for humans has lead to a dramatic decline in their numbers and left them at serious risk of extinction.

Scientific Name
Chelonia mydas

Conservation status
Green turtles are classified as Endangered by the International Union for Conservation of Nature (IUCN)

Description
Adults have a smooth, high-domed carapace (top of shell) that is an olive green colour with occasional brown, reddish-brown or black mottling. Adult carapace length averages 1 metre.

Hatchlings have a black carapace with white edges, white edges on their flippers and plastron (under part of shell).

Distribution
Green turtles are found in tropical and subtropical waters in the Atlantic, Pacific and Indian oceans as well as the Caribbean and Mediterranean Seas. They can be found in over 140 countries and nest in 80 different countries.

Diet
Green turtles are the only species of turtle that principally eats plants. Adults mostly feed on seagrass though they also eat algae and sponges. They will also occasionally feed on jellyfish and other invertebrates.

Hatchlings are omnivorous (feeds on plants and animals) and will eat anything edible they find.

Habitat
The Atlantic and Pacific populations are sperated from each other by cold water, and differences in food preferences and habitat have arisen. After a juvenile period in the open ocean they move to shallow reefs and seagrass beds where they establish a feeding ground. They may remain at these feeding grounds for many years, often returning to the same sleeping spot every night.

Lifecycle
Once hatchlings emerge from the nest they enter what is known as the oceanic phase, a period for which little is known. When they reach approximately 6 years or 5 kg they return to coastal waters where they forage and grow until sexually mature: 26-27 years in the Caribbean and 30-40 years in Australia. The long time to reach maturity is due to their low protein diet. Once they reach maturity they migrate every 2 to 6 years between nesting and foraging sites, which can be thousands of kilometres apart.

Nesting
Green turtles may share their feeding grounds with other green turtles that migrate to nest in a totally different location. Based on tagging evidence, green turtles nesting in the Great Barrier Reef, Australia migrate from Indonesia; Torres Strait; Papua New Guinea; the Solomon Islands; Vanuatu; New Caledonia; Arnhem Land, Northern Territory, Australia and; the Gulf of Carpentaria, Australia. Green turtles nesting along the West Australian coast migrate from Indonesia, Queensland, Australia and the Northern Territory, Australia.