Author: TonyB

The Great Barrier Reef is the largest structure built by living organisms on the Earth today.
The Great Barrier Reef region is the world’s largest group of coral reefs.
The Great Barrier Reef Marine Park covers an area of 345 400 sq. km or 133 360 sq. miles.
It stretches 2300 km (1430 miles) along the Queensland coast.

There are three main types of reefs found on the Great Barrier Reef: Ribbon, Platform, and Fringing reefs.

Fringing reefs are coral structures that are attached to the mainland or to continental islands. In the Great Barrier Reef most fringing reefs are found around islands. Fringing reefs are probably the reef type most commonly seen by visitors.

Platform reefs are also known as patch reefs and are scattered in the calm, shallow waters between the mainland and edge of the continental shelf. They are usually round or oval patches and often tend to be broken up.

Ribbon reefs only occur in the northern part of the Great Barrier Reef. They form along the edge of the continental shelf and can grow so high they form narrow walls.

Tiny masses of coral polyps are responsible for building coral reefs.
Reefs are masses of limestone made from skeletons of millions upon millions of tiny marine animals and plants.

It is not one long continuous reef, but a complex system of various marine habitats with more than:
2900 coral reefs
600 continental islands
300 coral cays

The Great Barrier Reef is home to approximately:
1,500 species of fish
360 species of hard coral
1/3 of the world’s soft corals
4,000 species of molluscs (eg. shells)
800 species of echinoderm (eg. starfish, sea urchins etc)
24 species of seabirds that live and breed on the islands
More than 30 species of marine mammals including whales, dolphins and dugongs
14,000 dugong (Australia’s entire dugong population is about 100,000)
6 species of marine turtles, all listed as threatened.

Main threats to coral reefs include climate change, pollutants, coral bleaching and crown-of-thorn starfish outbreaks.