Expert Report

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Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. This report explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication.

Key Messages

  • At present, there is little accessible information or easily implemented and reliable methods for a decision maker or program manager in a coastal area to determine the sources of excess nutrients or the potential impacts of those nutrients to a specific coastal water-body.
  • Estuaries and coastal zones are among the most productive ecosystems on earth. There is strong concern that the natural resources they represent are in danger from eutrophication and other problems caused by excess input of nutrients.
  • Federal leadership is essential to support and coordinate the research and development needed to provide new approaches and technologies that can be used by local and state agencies charged with reducing and reversing the impacts of nutrient over-enrichment.
  • Implementation of a National Nutrient Management Strategy to improve the understanding and management of nutrient over-enrichment and eutrophication requires action at two levels, local and federal.
  • Nutrient-over-enrichment is significant problem for the coastal regions of the United States.
  • One of the first federal actions taken under the National Nutrient Management Strategy should be to develop and implement a process to assess overlaps and gaps in existing and proposed federal programs for all aspects of nutrient over-enrichment, with particular attention to the needs of local managers.
  • The National Nutrient Management Strategy should coordinate local, state, regional, and national efforts to combat nutrient over-enrichment in coastal areas, with the goal of seeing significant and measurable improvement in the environmental quality of impaired coastal ecosystems.
  • The major nutrients that cause eutrophication and other adverse impacts are nitrogen and phosphorus.
  • The problems caused by nutrient-enrichment are likely to increase as human use of inorganic fertilizers and fossil fuels.
  • The severity of nutrient-related problems and the importance of the coastal areas at risk demand the development and implementation of a National Nutrient Management Strategy.
  • There is no nationwide strategy designed specifically to address excess nutrient inputs to coastal waters.