People are more and more damage to coral Reef ecosystems, creating a large change in the environment, of a kind rarely encountered or continuous over large areas so long evolutionary history of coral reefs. These environmental changes, coral reef communities have developed any long-term defense.

Here we discuss the three major threats currently posed by human activities, which could be the correct adjustment of control quickly. The fourth major threat, the current global warming is a long-term problem is not a short-term solution.

First overload of nutrients (eutrophication). Under natural conditions, contain tropical ocean intrinsically low levels of dissolved nutrients (nitrates and / or phosphates). This, combined with grazing by herbivorous reef, actions to maintain the growth of macroalgae on the surfaces of corals to a minimum. But when the waters around coral reefs become abnormally enriched with nutrients, growth of macroalgae over the ability of herbivorous reef to keep vegetation in check. Macroalgae reigned, and the substrate reefs "shift" from one dominated by coral living in a place largely covered with algae.

Therefore, a particularly destructive pollution of coral reefs is the rejection of the other "algae limiting" nutrients in coastal marine environments. Forms of wastewater, storm water, fertilizer and other nutrients responsible for unloading the homes, factories and farmland inland often carried out directly by the Sea coastal rivers and canals, or filtered through porous soils of the underlying aquifer and then travel many miles to finally come out in the coastal waters and coral reef areas.

Recent research has shown that coral reefs have a very low tolerance for a form of pollution, apparently a very small increase in dissolved nutrients from the moment can lead to wholesale changes in the reef platforms. This is probably the main cause of damage to reefs in many coastal areas, such as Shallow seas that bathe the only living coral reef can be found in the continental United States - the Florida Keys.

2. Sedimentation. When upland forests and coastal areas and savannahs are stripped of natural vegetation by logging and burning, there is little to catch or retain the soil. The rains carry more sediment loads directly into streams and rivers that flow into the sea following the similar effects can be produced by the activities related to development and urbanization of coastal areas. This often involves a boat channel dredging, construction of marinas and resorts, and deposition (dumping) of construction materials into the sea.

These land-based activities have the ability to quickly destroy coral reefs, unless properly designed and controlled. Water clouded with silt is not conducive to reef growth or survival. Corals vary in their ability to dispose of sediment - some are capable of handling small quantities quite well, but many are not.

The sediments of cloud water, reducing sunlight for photosynthesis, smothering of live coral, and reduce the ability of coral reef fish to see and catch prey. Removal of coastal mangrove and seagrass - that are very effective natural sediment "traps" - reinforces this problem by allowing greater amounts of terrestrial sediments to spread in coastal waters. Cloudy water also inhibits or prevents photosynthesis.

3. Overfishing. Overfishing refers to the collection of the population can not maintain the level of fishing / harvesting pressure, which continued population decline. For coral reef ecosystems, overfishing and habitat use of destructive fishing / harvesting destroyed the coral reefs and associated marine life in coral reef areas in much of the world.

The use of poisonous chemicals, including bleach, soaps, and even cyanide roll the marine life of the reef or paralyze catch fish is common today in many reef areas, despite of prohibitory legislation. Worse explosives commonly used in some areas to stun and kill fish. Such structure of the reef break, destroy in a moment that took thousands of years to create.

Trapping fish for local markets, collecting shells and coral souvenirs, jewelry and trinkets, and the collection of minor reef fish for the aquarium, are increasingly serious problems for the health of reef environments coral communities. The removal, by any means, an excessive number of animals of the reef areas can have lasting negative effects on many aspects of the evolution of Reef ecology and community effects little known today.