- Overfishing and destructive fishing
- Land-based and marine-based pollution
- Coastal development
- Tourism and recreational impacts
Of these local threats, overfishing is considered the most widespread threat as it affects over half of all reefs worldwide. Coastal development and land-based pollution each affect about 25% of coral reefs globally. Coral reefs in Southeast Asia are thought to be most vulnerable to local stressors, with nearly 95% of reefs considered threatened.
The map below shows the change in local threats for coral reefs areas worldwide between 1998-2007 based on the 2011 Reefs at Risk Revisited report. ref
Over the last decade, human impacts on coral reefs have increased significantly. Consequently, the percentage of the world’s reefs threatened by a combination of local stressors has increased by more than 30% during that time.