tive expense of comprehensive surveys, and the complex dynamics and spatial heterogeneity of marine ecosystems. In addition, the species-specific approach may fail to address changes that affect productivity throughout the ecosystem. These changes may include natural fluctuations in ocean conditions (such as water temperature), nutrient over-enrichment from agricultural run-off and other types of pollution, habitat loss from coastal development and destructive fishing practices, bycatch of non-target species, and changes in the composition of biological communities after removal of either a predator or a prey species.
In addition to challenges presented by nature, management challenges arise from social, economic, and institutional structures. Regulatory agencies are charged with the difficult but important task of balancing the needs of current users with those of future users of the resource as well as the long-term interests of the general public. Regulatory actions intended to maintain productivity often affect the livelihoods of the users and the stability of coastal communities, generating pressure to continue unsustainable levels of resource use to avoid short-term economic dislocation. Finally, responsibility for regulating activities in marine areas, extending from estuarine watersheds to the deep ocean, is fragmented among a daunting number of local, state, federal, and international entities. This complexity in jurisdictional responsibility often places a major barrier to developing coordinated policies for managing ocean resources across political boundaries. Although the protected area concept, with its emphasis on management of spaces rather than species, is not new and has been used frequently on land, until recently there have been less support and few interagency efforts to institute protected areas as a major marine management measure. MPA-based approaches will shift the focus from agency-specific problem management to interagency cooperation for implementing marine policies that recognize the spatial heterogeneity of marine habitats and the need to preserve the structure of marine ecosystems.
To address these issues, the National Oceanic and Atmospheric Administration (NOAA), National Park Service, and Fish and Wildlife Service requested that the National Research Council's Ocean Studies Board assemble a committee of experts to examine the utility of marine reserves and protected areas for conserving marine resources, including fisheries, habitat, and biological diversity. Although there are other, equally important goals, for MPAs, including recreation, tourism, education, and scientific inquiry, examination of these objectives was not part of this committee's specified statement of task and hence receives less emphasis in this report. The committee was directed to compare the benefits and costs of MPAs to more conventional management tools, explore the feasibility of implementation, and assess the scientific basis and adequacy of techniques for designing marine reserves and protected areas. This report presents the findings of the study and provides recommendations for the application of marine reserves and protected areas as a tool in marine area management.