BOX 3-1 Nutrient Contamination of Coastal Waters: Attacking a Difficult Problem

Maintaining the chemical and biological integrity of coastal waters in the face of an influx of nutrients and other pollutants generated by continuing demographic, economic, and technological growth in the watersheds of coastal areas has become a major challenge. Past efforts to protect coastal waters by addressing thermal pollution, soil loss and sediment control, toxic substances, and dredging have deflected attention from what is probably the most significant threat to many coastal waters—excessive nutrient loading. Nutrient inputs to aquatic ecosystems lead to deficiencies of dissolved oxygen. Degraded water quality, in turn, has significant negative impacts on biological resources, such as fish and shellfish. Rapid population growth, coastline development, increases in agricultural fertilization and the density of farm animals, and atmospheric inputs continue to increase the severity of the problem.

To mitigate nutrient contamination of coastal waters, problem-driven research is needed to answer questions such as the following:

  • What are the details of the major routes of nitrogen from agriculture through the ground water into coastal regions? How might controls be effectively applied?

  • What is known about the relationship between alternative land-management strategies and water quality? What is known about the relationships between regulations and incentives, such as zoning restrictions, tax incentives, and trading of pollution and other permits with a quota, and resulting land-use patterns and water quality?

  • How can nitrogen inputs to drainage areas including those from atmospheric sources such as the combustion of fossil fuels be controlled, and what are the costs and benefits of potential control strategies?

  • How is water quality related to nonpoint-source pollutant inputs such as those from agricultural and atmospheric sources? How are the biological resources of coastal areas related to water quality?

  • How quickly, if at all, will coastal water quality improve following reduction of pollutant inputs?

Consistent monitoring and accurate modeling are also needed to understand natural cycles, ascertain anthropogenic sources of variability, indicate the efficacy of pollution control programs, delineate research needs, and identify potential problems as they begin to develop. Monitoring and modeling must be coordinated and interactive. A key task will be to characterize and quantify the nonpoint sources of contaminants.



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