A tropical coral reef is a vibrant underwater ecosystem found in warm, shallow ocean waters, typically near the equator. These reefs are built by tiny marine animals called coral polyps, which secrete calcium carbonate to form hard structures. Coral reefs support a diverse range of marine life, including fish, mollusks, and crustaceans, making them one of the most productive ecosystems on Earth. Coral reefs provide essential benefits, such as protecting coastlines from erosion and supporting local economies through fishing and tourism. They also play a crucial role in maintaining marine biodiversity, serving as habitats for thousands of species. However, coral reefs face threats from climate change, pollution, and overfishing.