Widely distributed species in tropical and subtropical waters, but rare in temperature waters.
Because of feeding behavior of adults (feeding with sea-grasses), occasionally forms feeding
aggregations in some regions. This species can migrate from nesting sites to feeding grounds,
which are sometimes several thousands kilometers away.
The major nesting beaches of Atlantic population are in Costa Rica, Venezuela, Suriname, Brazil and Cape Verde Islands. Nesting sites in Seychelles and Comoro Islands, Yemen, southeast of Malaysia and Australia. Beside loggerhead, green turtle is the only remain species which nest in the Mediterranean (Cyprus, Turkey), where the female nesting population is estimated between 500 and 1,000 specimens.
The last records of green turtle in the Adriatic are dated from XIX century.
Because of the wide distributional range of the species, the nesting season varies among distant and near localities. Females are usually returning to lay eggs near same spot where they left the last clutch, or even on the same beach from which they emerged as hatchlings. The breeding occurs in cycles, every 3 to 4 years. The majority of green turtles lay between 2 and 5 clutches in one nesting season. The mean clutch size varies from minimum 38 to maximum 195 eggs per clutch. Incubation in sand normally extend from 48 to 70 days. Hatching and emergence occur at night, and simultaneously. The green turtles reach sexual maturity in range between 25 and 30 years. The adult specimens are generally bigger (longer) than loggerhead adults (between 80 and 110 cm, Curved Carapace Length).