The Reef (geological formation)

A reef is a natural underwater structure built mainly from the calcium carbonate skeletons of corals and other marine organisms. Over time, these tiny coral animals secrete hard skeletons that accumulate and solidify, forming dense, often vibrant habitats. Reefs typically develop in warm, shallow ocean waters and serve as crucial ecosystems supporting diverse marine life. They also protect coastlines from erosion and provide resources for humans. Reefs can be natural or result from volcanic activity, but most well-known reefs, like the Great Barrier Reef, are biological formations created over thousands of years through these biological processes.