same types of policy options exist (e.g., technical or financial assistance for energy conservation or other reductions in NO_x emissions, regulations limiting allowable emissions, energy use taxes, and emission taxes), these policies would generally have to be implemented regionally or nationally to combat atmospheric sources of nutrients.

Because the appropriate choice of both the water quality target and the choice of policies to achieve that target are site-specific, a national recommendation regarding policy design is inappropriate. However, as part of a national strategy aimed at helping local managers reduce nutrient over-enrichment, the Committee recommends that a web-based clearinghouse for information relating to nutrient over-enrichment be developed. One component of that clearinghouse should be the compilation of three types of information that would aid local managers in developing nutrient management strategies that are appropriate for their estuaries:

• The first type of information would be a summary of and guide to research on the economic impacts of alternative source reduction methods, with particular emphasis on the role of site-specific characteristics in determining those impacts. This information would allow a local manager to determine which source reduction methods are likely to be more effective and cost-efficient, given the characteristics of the watershed and estuary of concern. For example, a manager of a local estuary with excessive nutrient inputs from agriculture could find information on the cost and effectiveness of various agricultural best management practices (see Chapter 9).

• The second type of information would be a summary of and guide to research on the effectiveness of alternative policies in achieving the most effective forms of source reduction, again given local circumstances. For example, if particular best management practices are identified as effective for a given watershed, this second type of information would provide a manager with information on the likely effectiveness of alternative policies in promoting increased adoption of those practices.

• Thirdly, the clearinghouse should contain documented case studies of both successful and unsuccessful attempts by local managers to combat nutrient over-enrichment in different types of estuaries. This would include not only attempts based on local policy implementation, but also documentation of attempts by local managers to work with regional or federal officials to combat nutrient loadings that originate outside the watershed, such as those from atmospheric sources.

By providing meaningful and easily understood information about