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, dest ructive fishing, poorly regulated mining and construction, and anthrop ogenic nutrients. However, coral cover has declined on reefs tens to h undreds of kilometers from direct or concentrated anthropogenic influe nce. Typical symptoms of reef decline are loss of branching and head c orals, increasing abundance of benthic algae and filter-feeding animal s, destabilized herbivore populations, and increased bioerosion. Chang es in benthic communities are consistent with observations that nutrie nt flux to marine communities is increasing in direct proportion to gr owing human populations in adjacent areas.