What are the pressures or stresses posing risks and damage to coral reef ecosystems?
Coral reefs are subject to naturally occurring environmental pressures and also to those resulting from human activities. Constantly occurring and gradual temperature changes and sea–level changes over the millennia and shorter term diseases, storms, and assaults from natural predators are among the most important natural environmental stresses. Effects can be cumulative over time, and coral reefs also can face multiple threats simultaneously or over a very short time period. Environmental pressures resulting from human activities involve coastal development resulting from growing populations in coastal areas; chemical pollutants either in the form of toxic contaminants or nutrient enrichment; over–harvesting of fish resources and associated destruction of reefs and related habitats; direct harvesting for sale or trade of coral colonies or of exotic fish species living amidst the reefs; groundings of boats and ships and damages resulting from improper anchorage; adverse impacts associa
