More than one-quarter of the world’s reefs are threatened by watershed-based pollution (including nutrient fertilizers, sediment, pesticides, and other polluted runoff from the land), with about 10 percent considered to be highly threatened. Southeast Asia surpasses all other regions with 45 percent of reefs threatened. This indicator focuses on erosion and sediment dispersion in river plumes, so it likely underestimates the threat from nutrients and pesticides, which tend to travel further from river mouths.