Final answer:
The Great Barrier Reef is significant due to its biodiversity, protective role, and economic importance.
Step-by-step explanation:
The Great Barrier Reef is significant to Australia and the world due to several reasons. Firstly, it is one of the most biodiverse ecosystems on the planet, housing thousands of species of fish, corals, and other marine life. Secondly, it acts as a natural barrier, protecting Australia's coastline from the damaging effects of ocean waves and storms. Finally, it is a major tourist attraction, contributing significantly to Australia's economy and global tourism industry.
Learn more about Significance of the Great Barrier Reef