The Great Barrier Reef is the largest coral reef system in the world, composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres over an area of approximately 344,400 square kilometres.

The reef is located in the Coral Sea, off the coast of Queensland, Australia. The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms.

This reef structure is composed of and built by billions of tiny organisms, known as coral polyps. It supports a wide diversity of life and was selected as a World Heritage Site in 1981.

The Great Barrier Reef is home to a wide diversity of marine life, including over 400 species of hard and soft corals, over 1,500 species of fish, over 4,000 species of mollusks, and over 400 species of marine mammals.

The reef is also home to a number of threatened species, including the dugong, the green sea turtle, and the humpback whale.

The Great Barrier Reef plays an important role in the marine ecosystem. It provides a habitat for a wide variety of marine life, and it helps to protect the coastline from erosion.

The reef also plays a role in the global carbon cycle, helping to absorb carbon dioxide from the atmosphere.

The Great Barrier Reef is facing a number of threats, including climate change, pollution, and overfishing.

Climate change is causing the ocean to become warmer and more acidic, which is harming coral reefs.

Pollution from agriculture, industry, and coastal development is also harming the reef. Overfishing is depleting the reef's fish populations, which are important for the reef's overall health.

The Australian government is working to protect the Great Barrier Reef. The government has implemented a number of measures to reduce pollution, overfishing, and other threats to the reef.

These measures include the Great Barrier Reef Marine Park Act, which protects the reef from development and pollution, and the Reef Water Quality Protection Plan, which aims to reduce pollution from land-based sources.

The Great Barrier Reef is the world's largest single structure made by living organisms. The reef is home to a wide diversity of marine life, including over 400 species of hard and soft corals, over 1,500 species of fish, over 4,000 species of mollusks, and over 400 species of marine mammals.

The reef plays an important role in the marine ecosystem, providing a habitat for a wide variety of marine life and helping to protect the coastline from erosion.

The reef is facing a number of threats, including climate change, pollution, and overfishing. The Australian government is working to protect the Great Barrier Reef by implementing a number of measures to reduce pollution, overfishing, and other threats to the reef.

The Great Barrier Reef is a natural wonder that is home to a wide diversity of marine life. It is important to protect the reef from the threats it faces so that it can continue to thrive for future generations.