humphead parrot fish nearly a meter and a half in length their jaws are so powerful they can bite through Rock when they descend to feed the reef itself is under threat they are indiscriminate feeders taking both Rock and coral alike in their quest for algae these fish play a large part in the erosion of the reef The Rock and coral they swallow emerge is later as a fine sand on a single Reef they can produce tons of it every year this soft sand forms the tropical beaches that we find so alluring over time the sand builds up to form an island which is then colonized by animals and [Music] plants trees take root Birds arrive the guano from thousands of turns which have chosen to Nest here enriches the sandy soil which then can support more plants