The eutrophication problem illustrates how human activities on land can degrade the quality of coastal waters and habitats, with potentially large economic and ecological costs. Solutions to the coastal eutrophication problem require changes in all these activities within the watersheds and airsheds connected to coastal waters. Commitments to these solutions are now beginning – the European Union's Water Framework Directive mandates strategies to reduce N and P delivery to coastal waters, and a 2000 National Research Council report recommended a National Coastal Nutrient Management Strategy for the United States.
Proposed solutions to the eutrophication problem are multidimensional and include actions to restore wetlands and riparian buffer zones between farms and surface waters, reduce livestock densities, improve efficiencies of fertilizer applications, treat urban runoff from streets and storm drains, reduce N emissions from vehicles and power plants, and further increase the efficiency of N and P removal from municipal wastewater. As coastal fish and shellfish aquaculture expand, management considerations of this rapidly growing internal source of nutrients will be required as well.