CORAL-REEF DECLINE

Coral reefs are deteriorating worldwide, with some of the most serious losses occurring in the western Atlantic Ocean and the Caribbean Sea. Direct damage or destruction of reefs occurs from sedimentation, destructive fishing, poorly regulated mining and construction, and anthropogenic nutrients. However, coral cover has declined on reefs tens to hundreds of kilometers from direct or concentrated anthropogenic influence. Typical symptoms of reef decline are loss of branching and head corals, increasing abundance of benthic algae and filter-feeding animals, destabilized herbivore populations, and increased bioerosion. Changes in benthic communities are consistent with observations that nutrient flux to marine communities is increasing in direct proportion to growing human populations in adjacent areas.