Species: Chelonia mydas
Bundjalung name: Unknown
Status (IUCN):  Endangered

Characteristics

• Length/size: Green sea turtles are the largest species of hard shelled marine turtles and the second largest turtle species in the world. Adult turtles can weigh anywhere from 100-160kg but as hatchlings they weigh only 20g. They have small pin sized heads with a high domed carapace. Their carapace can be up to 1m in length and they usually weigh on average 150kg.

• Colour: In adults the carapace is usually a light to dark green colour with dark mottling, with a white plastron. Hatchlings have black to dark brown carapace, with white margins and a white plastron. Juvenile green turtles can have more of a brownish colouration to their carapace.

• Breeding/reproduction: Sexual maturity occurs between 30-40 years of age. Green sea turtles can lay between 1-7 different clutches of eggs in a season. On average, each one of these clutches should contain around 110-115 eggs within each. Females rarely return to nest the following, often waiting as long as 4-7 years before coming back to nest again. Green turtles that nest on the Australian coast migrate from numerous feeding grounds dispersed through Indonesia, Papua New Guinea, Solomon Islands, Vanuatu, Fiji and New Caledonia. They undertake long migrations between feeding grounds and nesting beaches.

• Diet: Unique amongst other sea turtle species in that they are primarily herbivorous, eating mostly seagrasses and algae. It is this ‘green’ based diet that gives their cartilage and fat a greenish colour (not their shells), which is where their common name is derived from. Adult green turtles are completely vegetarian, feeding strictly on seaweeds, seagrass (Halophila ovata), mangrove fruits and algae. While juveniles are omnivores and often opportunistic feeders, feeding on jellyfish, algae and seagrass.

Habitat: Green turtles can be found in all temperate and tropical waters throughout the world. They are usually found around the coastlines, islands, bays or protected shores, especially in areas with seagrass beds.Green turtles nest in more than 80 different countries around the world.

Threats: Green turtles are at a high risk of extinction due to climate change and increasing nest temperatures. Adverse weather events, like flooding, will continue to worsen with climate change, as well as increasing sand temperatures, which are causing a potential feminisation of populations and increased nest mortality in some areas of Australia. These events also impact their foraging grounds (coral reefs and seagrass meadows). Other threats include  marine debris, entanglement (drowning in crab pots), light pollution and habitat modification due to coastal development. Northern NSW beaches are becoming increasingly recognised for critical habitat for green sea turtles. Beaches here in NSW can provide climate refugia, as well as stretches of remote beaches, where threats from visitation and development may be lessened, improving nesting success, hatchling emergence rates and improve  survivability.