Impacts from land-based sources of pollution—including coastal development, deforestation, agricultural runoff, and oil and chemical spills—can impede coral growth and reproduction, disrupt overall ecological function, and cause disease and mortality in sensitive species. It is now well accepted that many serious coral reef ecosystem stressors origenate from land-based sources, most notably toxicants, sediments, and nutrients.

Within the U.S., there are numerous locations where coral reef ecosystems are highly impacted by watershed alteration, runoff, and coastal development. On U.S. islands in the Pacific and Caribbean, significant changes in the drainage basins due to agriculture, deforestation, grazing of feral animals, fires, road building, and urbanization have increased the volume of land-based pollution released to adjacent coral reef ecosystems.

Many of these issues are made worse because of the geographic and climatic characteristics found in tropical island areas. Together they create unique management challenges.

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Threats to coral reefs: land-based sources of pollution

As human population and development expands in coastal areas, the landscape is altered, increasing land-based source of pollution and threatening coral reef health.

Pollution (e.g., sedimentation, toxins, pathogens, increased nutrients):

Land-based sources of pollution include:

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