Atolls are ring-shaped coral reefs, not islands.

The Great Barrier Reef is the largest coral reef system in the world.

Coral reefs are formed by the accumulation of calcium carbonate produced by coral polyps.

Volcanic activity is not a major threat to coral reefs, although it can cause localized damage.

Cays are small, low-lying islands formed from sand and coral debris.

The Maldives is renowned for its coral reefs and marine biodiversity.

Coral reefs grow and expand through a process called accretion, where new coral colonies form on top of existing ones.

Patch reefs are not a type of coral reef structure, but rather isolated coral colonies that grow in deeper waters.

Coral and certain types of algae have a mutualistic relationship, where both organisms benefit from the association.

Tuna are not a major type of coral reef fish, as they are typically found in open waters.

Coral reefs provide habitat for a wide variety of marine organisms.

Artificial reef creation is not a conservation measure for protecting coral reefs, as it does not address the underlying causes of reef degradation.

Coral bleaching is the process by which coral reefs lose their vibrant colors and become bleached.

Natural predators are not a major cause of coral bleaching.

Coral recovery is the process by which coral reefs recover from bleaching and regain their vibrant colors.