The coastal marine environment is clearly being affected by the modification and destruction of habitats, over-fishing and pollution. Many of these impacts can be traced back to land-based human activities located far from the sea.
The deterioration of the marine environment in the Florida Keys is no longer a matter of debate. There is a decline of healthy corals, an invasion of algae into seagrass beds and reefs, a decline in certain fisheries, and an increase of coral diseases and coral bleaching. In Florida Bay, reduced freshwater flow has resulted in an increase in plankton blooms, sponge and seagrass die-offs, and fish kills.