The green turtle is a large and attractive marine turtle that spends almost its entire life at sea. However, during the summer months, the females come ashore to nest on some mainland beaches and many offshore islands of northern Australia. In the past, the animal was boiled up into soup and its fat was green, which is the reason for its name. Australia, along with 115 other countries, has now banned the import or export of products form marine turtles.
In Australia, there are four major green turtle nesting areas:
The southern Great Barrier Reef has 13 major rookeries, including North West Island, Wreck Island, Hoskyn Island, Heron Island and the Coral Sea cays. Nesting occurs between late November and January in southern Queensland. The northern Great Barrier Reef has five major rookeries, including Raine Island and nearby cays, and Bramble Cay in the Torres Strait. The southeastern Gulf of Carpentaria has three major rookeries at Bountiful, Pisonia and Rocky Islands.
Large numbers of greens occur in suitable feeding areas along the south-west coast of the Gulf of Carpentaria, adjacent to the Sir Edward Pellew Islands.
On the west coast, Green turtles are quite often seen in northern WA in areas such as Ningaloo Marine Park, Shark Bay Marine Park, the proposed Dampier Archipelago Marine Park, and sometimes also in the waters of southern areas such as Marmion and Shoalwater Islands Marine Parks and even as far south-east as King George Sound in Albany. Green turtles nesting along the WA coast migrate from feeding grounds in Indonesia, Queensland, Northern Territory and Western Australia.
Its appearance is that of a typical sea turtle. The green turtle s smooth, high-domed shell is mottled olive green, brown and black, but the species actually gets its name from the colour of its fat. People know what green turtle fat looks like because the turtle was hunted in Australia for its eggs and meat which was boiled into soup until it was given legal protection in 1973.
Its range extends throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Oceans. In the Pacific, its range reaches as far north as the southern coast of Alaska and as far south as Chile in the east. The turtle’s distribution in the Western Pacific reaches north to Japan and southern parts of Russia’s Pacific coast and as far south as the northern tip of New Zealand and a few islands south of Tasmania. The turtles can be found throughout the Indian Ocean.
The Great Barrier Reef has two genetically distinct populations; one north and one south. Within the reef, twenty separate locations consisting of small islands and cays were identified as nesting sites for either population of C. mydas. Of these, the most important is on Raine Island.
The green turtle lives around coral and rocky reefs and seagrass meadows in tropical and subtropical seas. The green turtle likes to bask on the water s surface, making it very vulnerable to being hit by boats. Green sea turtles move across three habitat types depending on their life stage. They lay eggs on beaches. Mature turtles spend most of their time in shallow, coastal waters with lush seagrass beds. Adults frequent inshore bays, lagoons and shoals with lush seagrass meadows. Entire generations often migrate between one pair of feeding and nesting areas.
Like other sea turtles, they migrate long distances between feeding grounds and hatching beaches. Many islands worldwide are known as Turtle Island due to Green sea turtles nesting on their beaches. Females crawl out on beaches, dig nests and lay eggs during the night. Later, hatchlings emerge and walk into the water. Those that reach maturity may live to age 80 in the wild.
Pacific green turtle s foraging habitats are poorly understood and are mostly unknown. Adult greens feed mostly on seaweeds and seagrasses although immature greens are carnivorous.
The green turtle is an endangered species. Crabs, goannas, herons, gulls, foxes and fish such as sharks and trevally all make a meal of hatchlings. Each year turtles drown in fishing gear and are strangled or choked by rubbish. Dredging (the removal of sediment from the sea floor to make a channel deep enough for larger boats) can damage the turtles seagrass beds. Coastal developments such as marinas and high-rise buildings can also disturb turtles nesting beaches. And in many countries, hunting has drastically reduced the turtle population. The green turtle is protected in Australian waters, and hunting is restricted to traditional use by Aboriginal people.