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The Great Barrier Reef Ecosystem

The Great Barrier Reef, located off the coast of northeastern Australia, is the world's largest coral reef system. Composed of over 2,900 individual reefs and 900 islands, it stretches for over 2,300 kilometers and is one of the most biodiverse ecosystems on Earth. The reef's structure is built by billions of tiny organisms known as coral polyps. These polyps form colonies that secrete calcium carbonate to create a hard skeleton, which accumulates over generations to form the massive structures of the reef. The reef is so large that it can be seen from outer space.

The reef supports an extraordinary variety of life. It is home to thousands of species of fish, mollusks, and crustaceans, as well as larger animals like sea turtles, dolphins, and sharks. This rich biodiversity is possible because the complex structure of the coral provides shelter and food for a vast number of organisms, creating an intricate food web. The reef is also of immense economic importance, supporting a thriving tourism industry and fisheries that are vital to the Australian economy.

Despite its beauty and importance, the Great Barrier Reef is under severe threat. Rising ocean temperatures are causing a phenomenon known as coral bleaching, where corals expel the symbiotic algae living in their tissues, causing them to turn white and often die. Ocean acidification, a result of increased carbon dioxide in the atmosphere, also hinders the corals' ability to build their skeletons. Pollution from land-based runoff and overfishing further add to the stress on this fragile ecosystem. Urgent conservation efforts are underway to protect the reef, but its future remains uncertain.