Some of the shortcomings of both regulatory and tax-based approaches can be overcome with the use of marketable permits. A careful examination of the effectiveness of this approach where it has already been implemented should be undertaken.
In many instances, managers may find that a well-formulated mix of incentives (voluntary approaches) and disincentives (mandatory or punitive approaches) works better than either approach alone. Managers might increase the likely success of a voluntary approach by making it clear that, if the voluntary approach is not successful, an approach based on disincentives will be adopted.
An information clearinghouse should be established that provides local managers with information about the cost and effectiveness of alternative source control methods, the effectiveness of alternative policy options, and the policy experiences that other managers have had in attempting to control nutrient over-enrichment. This information should emphasize the role of site characteristics in determining effectiveness and costs.
In developing an effective strategy for mitigating the effects of nutrient over-enrichment one must understand the physical and ecological relationships that determine the extent and causes of nutrient over-enrichment, along with societal objectives and behavioral responses. Societal objectives determine goals that a management strategy will strive to achieve and the benchmark against which it will be evaluated. Behavioral responses ascertain how the various parties contributing to nutrient over-enrichment are likely to respond to different policies designed to affect that behavior. Managers must anticipate and understand these responses as they choose among policy alternatives, since the responses will determine the effectiveness of any given policy.
This chapter discusses issues that arise both in setting goals for nutrient over-enrichment management strategies and in choosing among policy alternatives. The appropriate set of policies for any given estuary will depend on the nutrient sources for that estuary. For example, if the main nutrient source is agriculture, a set of policies designed to promote the adoption of best management practices is required. These can be implemented at the local, regional, or national level. Alternatively, if atmospheric deposition is the main source of nutrients, policies that reduce atmospheric emissions of nitrogen are needed. Since the source of atmospheric nitrogen is often outside the local jurisdiction governing the estuary, policies to combat this nutrient source must be implemented at the regional or national level. Because both the susceptibility and the specific policy needs of any given waterbody are site-specific, this chapter does not attempt to prescribe specific water quality goals or policy choices for adoption by local managers. Rather, it is intended to provide managers with an improved understanding of the factors that should be considered in setting goals and making policy choices. With this understanding, managers will then be able to begin the process of crafting a