Human Influences On Eastern Tropical Pacific Coral Communities and Coral Reefs

Abstract

Coral reefs world-wide have been impacted by direct and indirect human activity and natural disturbances. This has led to the degradation and disappearance of many reef structures. On a basin-wide scale, the natural impact of El Niño warming has been the main cause of reef decline in the eastern tropical Pacific (ETP). At local scales, human activity has also taken its toll although only limited observations are available on specific impacts to ETP coral reefs. The main direct causes of damage are the extraction of corals and other reef organisms, nonregulated tourist activity, ship groundings, anchor damage, and eutrophication. The main indirect sources of damage to coral reefs are coastal alteration, sedimentation, pollution (including eutrophication), oil pollution, agrochemicals, other pollutants, and plankton blooms. Climate change can impact coral reefs directly (sea warming, sea level rise, ocean acidification, increased storm activity, and possibly stronger and more frequent El Niño events), and indirectly (coastal erosion, increased fresh water runoff and elevated nutrients). Even though human impacts on ETP reefs are low compared to other regions, significant damage has been documented. Since ETP coral reefs are relatively small and few in number, a redoubled effort is necessary for their protection.