How Corals Build the Reef

This passage explains the fascinating process of how coral polyps build the Great Barrier Reef. It details the life cycle of coral, from free-swimming larvae to colony formation. The text describes how polyps secrete calcium carbonate skeletons, gradually building up the reef structure over thousands of years. It emphasizes the slow nature of reef formation and the importance of conservation efforts. The passage uses the analogy of underwater cities to illustrate the complex ecosystem created by corals. Keywords: coral polyps, reef formation, calcium carbonate, marine ecosystem, coral conservation, Great Barrier Reef, underwater cities.