Eretmochelys imbricata

Conservation status

International: ‘Critically Endangered’ [World Conservation Union]

Description

Adults: Carapace brown with extensive variegation of brown and black, strongly imbricated (overlapping scutes); plastron cream with occasional black spots; distinctive beak-like mouth and narrow head; carapace ~ 0.8 m

Hatchlings: Dark brown carapace and plastron

Distribution and habitat

Found in tidal and subtidal coral and rocky reefs in tropical and subtropical waters of all oceans of the world.

Diet

Mostly sponges, but also seagrass, algae, sea cucumbers, soft corals and shellfish. Their pointed jaws are well adapted to prising food from crevices in coral.

Breeding

Nesting season – Australia:

Year-round. Concentrating from November to late March in the Great Barrier Reef and Torres Strait and from July to September in the N Territory. Hatchlings emerge year-round, concentrated from February to early May in the Great Barrier Reef and Torres Strait, and from September to November in the N Territory.

Years between breeding 2-5 years

Average clutch size ~120 eggs

Average hatching success ~75%

Native predators on hatchlings Gulls, reef egrets, ghost crabs, dingoes, fish, crocodiles, sharks.

Breeding areas - Australia

Three major breeding areas:

• Northern Great Barrier Reef north of Princess Charlotte Bay – Milman, Johnson, Bouydong, Bird and Piper Islands; and the Torres Strait – Aukane, Kabikane, Mimi, Bet, Sassie, and Lacey Islands. The only high density nesting in the Great Barrier Reef is at Milman Island. The entire northern section of the Great Barrier Reef, and the Torres Strait is internationally important for Hawksbill Turtle nesting as the species has declined markedly in other parts of the world.
• Northeast Northern Territory – Hawk, NE and Truant Islands.
• Western Australia – Rosemary and Varanus Islands.

Main threats

Incidental capture in fishing and shark control program gear; ingestion of synthetic material; boat strike; predation of eggs and hatchlings; unsustainable indigenous hunting of adults and collecting of eggs; hunting of immature and adult turtles for tortoiseshell; increased incidence of disease.

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