Why are coral reefs in peril and what is being done to protect them?

Why are coral reefs in peril and what is being done to protect them?

Coral reefs are at risk from natural processes and human activities.

Oil spills and pollutants can threaten entire reefs.

Excessive nutrients from land, such as sewage and agricultural fertilizers, 

promote the growth of algae that can smother corals.

Coral productivity is also decreased when land development for agriculture, 

industry, and housing increases sediment carried to coastal waters as runoff.

Runoff clouds the water, blocking light needed for algae living in the corals.

When stressed, corals "bleach," expelling the algae critical to their health.

The USGS is helping to understand the biological and geologic controls...

that affect our Nation's coral reefs by mapping, monitoring, and studying them.

Visit USGS.gov for more information.