Great Barrier Reef

Queensland, Australia

Australia's Alluring Reef

The Great Barrier reef is one of Australia's best tourist attraction. It's the world's biggest coral reef. Located of the coast of Queensland, Australia stands a 2,300 km long reef, hundreds of islands, 600 plus types hard and soft coral, and countless fish, mollusks, starfish, turtles, dolphins, and shark. The Great Barrier Reef is one of the seven natural wonders of the world, and from a further view you can see why.

Forming a Reef

The Great Barrier Reef is relatively young at 500,000 years old, with it's most modern formation at 8,000 years old.


Coral Reefs begin to form when free-swimming coral larvae attaches to sunken rocks or other hard surfaces. The coral is made up of thin plates, or layers of calcium carbonate secreted by hundreds of soft bodied animals called coral polyps. Each polyp lives in symbiotic relationship with a host zooxanthellae that gives the coral it's color. There are two types of coral. Hard coral, which have rigged exoskeletons, and soft corals which sway with current and have a lack of exoskeleton. As the reef begin to form they either take on three major characteristic structures. Fringing, barrier, atoll reef. Fringing reefs, are the most common reefs, form borders along the shoreline and surrounding islands. Barrier reefs also border shorelines but at a greater distance. They are separate from their adjacent land mass by a lagoon. If a fringing reef forms around a volcanic island that is below sea level while coral begins to grow upwards, an atoll forms. Atolls are usually circular or oval with a central lagoon. Barrier reefs and atolls are also some of the oldest biologically diverse habitats in the ocean. With growth rates of 0.3 to 2 cm per year for massive corals and 10 cm per year for branching corals. Depending on their size barrier reefs and atolls usually take about 30,000,000 years to fully form.

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