The sea does not reward those who are too anxious, too greedy, or too impatient. US writer Coral reefs and associated seagrass and mangrove communities are among the most biologically complex and diverse ecosystems on Earth. They provide habitat to one-third of all marine fish species, build tropical islands, protect coasts from waves and storms, contain an array of potential pharmaceuticals, and support tourism and fishing industries worth billions of dollars. Coral reefs are also fundamental to the fabric of local communities, providing a source of food, materials, and traditional activities.
Recent evidence indicates that coral reefs are deteriorating worldwide, and many are in crisis.
Symptoms include loss of hard corals, increased abundance of algae, diminished recruitment of coral larvae, reduced biological diversity, and a dramatic increase in bleaching episodes and disease outbreaks. Scientists and managers still lack critical information about the causes, but evidence suggests a variety of human forces, including population increases, shoreline development, increased sediments in the water, trampling by tourists and divers, ship groundings, poor water quality from runoff and inadequate sewage treatment, overfishing, and fishing with poisons and explosives that destroy coral habitat. The resources and information on this page will highlight coral reefs, their past, present and future. Coral reefs, and their associated systems of mangroves and seagrasses, are the world's most biologically diverse marine ecosystems. Important assets to local and national economies, they provide fisheries for food, materials for new medicines, and income from tourism and recreation, as well as protect coastal communities from storms.