The Great Barrier Reef is not only in danger of coral bleaching but is getting eroded by both physically and chemically. Since coral reef is made of calcium carbonate (Lime), it is more vulnerable to chemical weathering. Calcium carbonate dissolves in carbonic acid. The acid is formed when rain water is mixes with carbon dioxide in the atmosphere. After the Carbonic Acid has deposited on the corals it then weathers it down. Physically, Strong winds and large waves that break apart the coral reef and moves large amounts of coral which are called Bommies. Other physical weathering includes parrotfish, molluscs, sponges that break apart the coral.