An Ocean Blueprint for the 21st Century - California Ocean ...

assisting in the implementation of actions needed to reduce, remediate, and prevent pollutionand degradation of the coastal and marine environment.The United States is particularly involved in the coordination, integration, and managementof marine pollution programs in the wider Caribbean region, including programsfor addressing upstream sources and protecting wetlands, mangrove swamps, coral reefs,and offshore areas. At the 2002 Summit, the United States launched the White Water toBlue Water initiative with a coalition of partners that includes the United Kingdom,France, Canada, the Netherlands, Caribbean island governments, nongovernmentalorganizations, and the private sector. The ultimate goal of the initiative is to improve thecapabilities of all coastal nations to manage watershed and coastal ecosystems for sustainabledevelopment. Participants hope that success in implementing the pilot phase in theCaribbean will encourage other regions in Africa and the South Pacific to follow suit.Addressing AtmosphericSources of PollutionFigure 14.6 Looking Skyward:Accounting for Airshed DepositionAtmospheric deposition of pollutants can also harmwater quality, aquatic resources, and human health.Atmospheric deposition accounts for between 10 and50 percent of the nitrogen entering estuaries alongthe East Coast and the Gulf of Mexico. 20,21 Majoratmospheric pollutants include nutrients, metalssuch as lead and mercury, pesticides, polycyclic aromatichydrocarbons, dioxins, furans, and persistenttoxic substances. Certain persistent toxins, such asDDT and PCBs, have even been measured in remotelocations, such as the Arctic and Antarctic, demonstratingthe extent of dispersal of pollutants by theatmosphere. Atmospheric deposition is also a significantsource of pollution in the Great Lakes; as muchas 90 percent of some toxic chemicals entering theGreat Lakes are believed to be the result of atmosphericdeposition. 22 Sources of atmospheric depositionare quite varied and include agriculture, incineration,coal-fired power plants, industrial facilities,and motor vehicles, as well as natural sources suchas forest fires, lightning, and volcanoes.Improving Control of Atmospheric SourcesAddressing atmospheric deposition requires controllingmultiple sources within a particular water body’sairshed, defined as the geographic area responsible for75 percent of the air pollutants that reach that body ofwater (Figure 14.6). The airshed can be ten, twenty,or even several hundred times larger than the areaof the watershed. To add to the complexity, differentpollutants exhibit different physical and chemicalbehaviors in the atmosphere, so the airshed of aparticular body of water may vary depending on thepollutant of interest.Watersheds (shaded areas) and corresponding airsheds (circles)■ Naragansett Bay■ Tampa Bay■ Chesapeake Bay■ Mobile Bay■ Pamlico Bay■ Lake PontchartrainThe atmospheric area affecting water quality within a watershedmay be ten to several hundred times larger than thewatershed itself. As shown here for oxidized nitrogen contributionsalong the East Coast, the extent of the calculated airshedsillustrates the states, regions, and nations that must coordinatein order to effectively manage atmospheric contributions towater quality.Source: U.S. Environmental Protection Agency. (Accessed January 2004).C HAPTER 14: ADDRESSING C OASTAL WATER P OLLUTION223