Coral Reefs

Outbreak of bio-eroders

Crown of Thorns (Acanthaster planci). Koh Similan, Boulder City, Thailand. Photo: Jon Hanson, 2005.

Bio-eroders play an important role in the development and maturation of coral reefs. They reduce the coral skeleton to sediment and weaken the coral structure so that pieces of coral break off or fall over. They can be active inside the coral (like algae, fungi, bacteria and sponges) or attack them from the outside (like sea urchins and starfishes).