Great Barrier Reef | WWF

Great Barrier Reef

About the Area

The Great Barrier Reef is the largest barrier reef system in the world, extending 2,000 kilometres from the low-latitude tropics to temperate zones. Comprised of the most diverse reef types, habitats, and environmental regimes, this is an area of enormous scientific importance.
Northern tropical waters are highly diverse, though there are relatively few endemic species. In contrast, the temperate portions of the reef have low overall species diversity but a higher proportion of endemic species. This enormous system and diversity of habitats support many forms of marine life.

There are an estimated 1,900 species of fish, approximately 350 species of hard-reef-building corals, more than 4,000 mollusc species, and over 400 species of sponge. In addition, these reefs harbour important nesting sites for numerous seabird species.

Local Species
Found within this ecosystem are unique habitats and breeding sites for the largest populations of Dugongs (Dugong dugon), and Saltwater crocodiles (Crocodylus porosus). Also found are Green sea turtles (Chelonia mydas), Flatback turtles (Natator depressa), Hawksbill sea turtles (Eretmochelys imbricata), Leatherback sea turtles (Dermochelys coriacea), and Olive ridley turtles (Lepidochelys olivacea).

Other species of interest include the Greater crested tern (Thalasseus bergii), Black cod (Epinephelus daemelii), Humpback whale (Megaptera novaeangliae), Minke whale (Balaenoptera acutorostrata), Killer whale (Orcinus orca), Bottlenose dolphin (Tursiops truncatus), Irrawaddy river dolphin (Orcaella brevirostris), Indo-Pacific humpback dolphin (Sousa chinensis), and the Spinner dolphin (Stenella longirostris).

Eutrophication, especially related to runoff from agricultural development (e.g., sugar cane), reduces coral reef diversity and spatial cover, while dumping of dredge spoil in the sea, adversely affects reefs by increasing turbidity and sedimentation.

Oil exploration, production, and their related dangers - e.g., accidental oil spills from islands and especially from passing ships - represent a threat. Overfishing, especially trawl and line fisheries, has a strong impact on the local marine fauna. Outbreaks of crown-of-thorns starfish (Acanthaster planci) have occurred, destroying a high proportion of hard coral cover.


Habitat type:
Tropical Coral

Geographic Location:
Northeast coast of Australia

Conservation Status:
Relatively Stable/Intact

Quiz Time!

Why was the Great Barrier Reef (GBR) named a World Heritage site?

Approximately 1,500 to 2,000 kilometres long, stretching along Australia's Eastern coast, from Cape York down to Brisbane - the GBR is the only living organism visible from outer space! It is also one of the 7 natural wonders of the world where coral reefs have been growing for more than 20 million years. All reasons enough for the United Nations to declare it a World Heritage site in 1981.

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