This report presents the first-ever detailed, map-based assessment of potential threats to coral reef ecosystems around the world. "Reefs at Risk" draws on 14 data sets (including maps of land cover, ports, settle-ments, and shipping lanes), information on 800 sites known to be degraded by people, and scientific expertise to model areas where reef degradation is predicted to occur, given existing human pressures on these areas. Results are an indicator of potential threat (risk), not a measure of actual condition. In some places, particularly where good management is practiced, reefs may be at risk but remain relatively healthy. In others, this indicator underestimates the degree to which reefs are threatened and degraded.Our results indicate that:
- Fifty-eight percent of the world's reefs are poten-tially threatened by human activity -- ranging from coastal development and destructive fishing practices to overexploitation of resources, marine pollution, and runoff from inland deforestation and farming.
- Coral reefs of Asia (Southeastern); the most species-rich on earth, are the most threatened of any region. More than 80 percent are at risk (undermedium and high potential threat), and over half are at high risk, primarily from coastal development and fishing-related pressures.
- Overexploitation and coastal development pose the greatest potential threat of the four risk categories considered in this study. Each, individually, affects a third of all reefs.
- The Pacific, which houses more reef area than any other region, is also the least threatened. About 60 percent of reefs here are at low risk.
- Outside of the Pacific, 70 percent of all reefs are at risk.
- At least 11 percent of the world's coral reefs contain high levels of reef fish biodiversity and are under high threat from human activities. These "hot spot" areas include almost all Philippine reefs, and coral communities off the coasts of Asia, the Comoros, and the Lesser Antilles in the Caribbean.
- Almost half a billion people -- 8 percent of the total global population -- live within 100 kilometers of a coral reef.
- Globally, more than 400 marine parks, sanctuaries, and reserves (marine protected areas) contain coral reefs. Most of these sites are very small -- more than 150 are under one square kilometer in size.
- At least 40 countries lack any marine protected areas for conserving their coral reef systems.