They are intimately connected to other marine communities such as mangrove forests, sea grass beds, and the open seas as water currents transport larvae, plants, animals, nutrients, and organic materials. Coral reefs play a significant role in the development of other ecosystems such as mangroves and wetlands and protect coastlines from wave and storm damage and erosion. Life-saving medicines, such as anticoagulants, and anticancer agents such as prostaglandins come from coral reefs. The rocky framework of coral reefs is formed from the calcium carbonate deposited mainly by calcareous algae and the stony corals, most of which are colonial animals resembling tiny, interconnected sea anemones. Reef-building corals contain symbiotic algae in their tissues, enabling them to develop the large, massive, branching, or encrusting carbonate skeletons that provide habitat and food resources for support of other reef organisms, such as fish, lobsters, giant clams, and sea urchins to name but a few.
Reefs maintain a network of intimate ecological relationships and delicate food webs.
Disruption of coral reef communities can break up these ecological bonds. Under natural conditions, a healthy coral reef can recover from natural disturbance such as hurricanes, within 10 to 20 years. But when subjected to chronic human-induced stress, recovery from even natural disturbance may be impossible. At least two-thirds of the world s coral reefs may collapse ecologically within the lifetime of our grandchildren, unless we implement effective management of these ecosystems as an urgent priority. Physical damage from tourists damaging the reefs, anchors dropped in coral beds, and ships colliding with reefs.