What is the name of the world’s largest coral reef system, off northeastern Australia?

The Great Barrier Reef is the world’s largest coral reef system, off northeastern Australia.

It lies in the Coral Sea along the coast of Queensland and extends for about 2,300 kilometres. The system includes thousands of individual reefs and hundreds of islands, making it much larger than a single continuous reef. The Great Barrier Reef Marine Park protects most of the region.

Its corals are colonial animals that build calcium-carbonate skeletons. The reef supports extraordinary biodiversity, including sea turtles, reef fish, sharks, dugongs, seabirds and many invertebrates. Warm, shallow water and sunlight allow the coral-algae partnership known as symbiosis to thrive.

The reef is vulnerable to marine heatwaves, coral bleaching, pollution, storms and changing ocean chemistry. Coral bleaching does not always mean immediate death, but prolonged stress can kill colonies. The Great Barrier Reef is also a World Heritage Site, listed by UNESCO in 1981.