Final answer:
The Great Barrier Reef, the world's largest coral reef system, is found in the Coral Sea off Australia's northeast coast and is known for its biodiversity and economic contributions.
Step-by-step explanation:
The Great Barrier Reef is located in the Coral Sea off Australia’s northeast coast. This marine ecosystem is a well-known reef system, characterized by high biodiversity, and is home to a variety of marine life, including over 4,000 fish species. Situated in shallow ocean waters within the photic zone, coral reefs are formed by marine invertebrates known as corals, which secrete calcium carbonate to create these staggeringly vast and complex structures.
Coral reefs, such as the Great Barrier Reef, not only support diverse marine life but also have significant impacts on their surrounding environment, contributing to local economies through tourism and serving as a natural protective barrier against waves and storms. The waters around these coral formations are often nutritionally poor, but the corals manage to thrive by forming a mutualistic relationship with photosynthetic unicellular algae, providing them with much-needed nutrients.