Answer:
Cays
Step-by-step explanation:
Cays: they are small, low-altitude, sandy islands formed on the surface of coral reefs. Eroded reef material piles up in certain parts of the reef or lagoon, forming an area above sea level. Plants can stabilize the keys sufficiently, such as to make it a habitable environment for humans. The keys occur in tropical Pacific, Atlantic and Indian environments (including the Great Barrier Reef, the Caribbean and the Belize Barrier Reef), and provide habitable and arable land for hundreds of thousands of people.