Sea Turtle Species Profiles
Austrailian Flatback Sea Turtle
Scientific Name: Natator depressus
IUCN/Conservation Status: Data deficient - According to the International Union for the Conservation of Nature (IUCN) Australian flatbacks are Data Deficient, meaning there has not been enough research conducted to determine the current status of their population (Red List Standards & Petitions Subcommittee, 1996). In Australia, these sea turtles are listed as Vulnerable under the Environmental Protection and Biodiversity Conservation Act, which is similar to the U.S. Endangered Species Act, in that it provides a legal framework to protect areas of national environmental significance (Australian Government, 2008). There are some exceptions to the flatbacks’ legal protections because of the cultural and social value these turtles have for indigenous peoples. Sea turtles have important cultural significance for Aboriginal and Torres Strait Islander people and also provide a protein source in these areas where food may be expensive or difficult to obtain. These communities are working with scientists to ensure sustainable management of these species (Australian Government, n.d.).
Habitat/Distribution: As their name suggests, Australian flatbacks are found in the waters of Australia, as well as Papua New Guinea. Feeding occurs in the waters of Northern Australia. They prefer turbid waters and spend time in soft-bottom habitats such as seagrass beds. Flatbacks have the smallest range of all sea turtle species (Australian Government, n.d.).
Diet: Australian flatbacks are omnivores with a wide range of prey including sea cucumbers, jellies, mollusks, and other invertebrates.
Size: As adults, Australian flatbacks weigh about 200 pounds, and their carapace measures about 91 centimeters (3 feet) in length (Sea Turtle Conservancy, n.d.)
Distinguishing Characteristics: Australian flatbacks have an oval-shaped, olive to gray colored carapace with 4 lateral scutes and pale brown edges. Each scute has dark grey edges and a lighter gray center. Their carapace is flattened with upturned edges, which earned these turtles the name flatback. As adults, their carapace also has a thin, fleshy skin covering it (Australian Government, 2008).
Maturity and Reproduction: Australian flatbacks reach maturity sometime between 7 and 50 years of age (Ripple, 1996).
Nesting: Unlike other sea turtle species, the Australian flatback does not migrate to mate and nest because the only nesting populations are located in Australia. There are 4 major nesting areas along the coast of the country. These 4 populations each have different peak nesting seasons. One of these populations nests all year long, while another has a mid-summer peak and another has a mid-winter nesting peak. Females will lay about 50 eggs, which are relatively large in size. Their eggs incubate for approximately 2 months. Hatchlings are larger than most species.
Conservation and Specific Human Impacts:
Along with the Australian flatback being considered Data Deficient by the IUCN, there is also very little information about the major threats they face as a species. Some known threats include predation by feral pigs, being caught as bycatch, and loss of habitat. Feral pigs are an invasive species and are known for sniffing out flatback nests and feeding on up to 90% of the eggs. Similar to loggerheads, Kemp’s, and olive ridleys, threats posed by commercial fishing are known to impact the Australian flatback. Near Cape York, many adult flatbacks have been caught in ghost nets. In northwestern Australia, the construction of oil and gas facilities threatens flatback habitat and light pollution in these areas threatens hatchlings (Australian Government, 2008).
Australian Government Department of Agriculture, Water, and the Environment. (n.d.) Marine Turtles in Australia.
Australian Government Department of Agriculture, Water, and the Environment. 2008. Natator Depressus.
Red List Standards & Petitions Subcommittee. 1996. Natator depressus. The IUCN Red List of Threatened Species 1996: e.T14363A4435952.
https://dx.doi.org/10.2305/IUCN.UK.1996.RLTS.T14363A4435952.en. Downloaded on 09 March 2021.
Sea Turtle Conservancy. (n.d.) Information About Sea Turtles: Flatback Sea Turtle.