Low coral reefs are shallow areas of the ocean floor that are home to a variety of marine life. They are typically found in warm, shallow waters and are made up of calcium carbonate structures built by living organisms such as corals, sponges, and other invertebrates. The term 'CAYS' is used to refer to small, low-lying islands that are formed from coral reefs. These CAYS are often surrounded by shallow lagoons and provide important habitats for a variety of species.