Marine turtles

Marine turtles are reptiles (cold-blooded vertebrate animals). Fossil records indicate they have lived within the world's oceans for over 100 million years, making them one of the few living links between the present and the time of the dinosaurs.

Green turtles (Chelonia mydas) are found in tropical, subtropical and temperate oceans around the world. They usually live among coral, rocky reefs and seagrass meadows of coasts and islands. Loggerhead turtles (Caretta caretta) are found in tropical and subtropical oceans worldwide. They also live among coral and rocky reefs and seagrass meadows of coasts and islands, as well as deeper, soft-bottomed habitats.

Eastern Beach of South Stradbroke Island is a confirmed nesting location for these turtles. They have also been recorded at other Gold Coast beaches.

Marine turtles are well adapted for life in the ocean. They have a streamlined body and strong flippers for propelling themselves through the water and for digging nesting chambers on the beach.

Adult green turtles weigh on average 150 kilograms. The carapace (shell) grows up to one metre long and has 4 scales along each side. Their upper shell is olive-green in colour and can also be brown, reddish-brown and black. The plastron (their underside) is a whitish-cream colour.

Loggerhead turtles are named after their relatively large-sized head. The average weight of an adult loggerhead turtle is 100 to 150 kilograms. The carapace grows to approximately one metre long and has 5 scales along each side. It is a dark reddish-brown in colour with darker brown markings. The plastron is creamy-yellow.

Status

Marine turtles are also recognised internationally as species of conservation concern. The green turtle is listed 'vulnerable' in Australia, meaning that it may become endangered if threats to its survival continue. The loggerhead turtle is 'endangered' in Australia, meaning it may become extinct.

Threats to turtles

Vehicles

Driving vehicles on the beach, particularly on the dunes, can destroy nests and cause sand compaction, making it difficult for turtle hatchlings to emerge from their nests. Deep tyre tracks in the sand can create a trap for the hatchlings, making them easy targets for predators and exposing them to high temperatures and dehydration.

Predators

Turtle nests and hatchlings are naturally preyed upon by lace monitors, crabs and birds. They are also put in danger when they cross paths with animals such as foxes, cats and dogs, which further decrease their chance of survival.

Offshore threats

Boat strikes, entanglement in nets and fishing lines and consumption of litter are a significant threats for marine animals worldwide. A number of deceased turtles have washed up on the beach at South Stradbroke Island.