Science for Ecosystem-based Management: Narragansett Bay in the 21st Century addresses the broad problem of coastal nutrient pollution. In the U.S., approximately two thirds of the coastal rivers and bays are moderately to severely degraded from nutrient pollution. However, debates continue about how large a problem nutrient pollution is and what actions to take, and since effective management requires decisions at a local scale, an in-depth case study can provide valuable guidance. Narragansett Bay is one of the best-studied estuaries in the world. Rhode Island has been developing regulatory and management actions to reduce nutrient inputs, particularly those of nitrogen, to the waters of Narragansett Bay. This book was developed in response to a symposium addressing this mandate with coastal/estuarine scientists and environmental management agency personnel. The contributors use long-term data sets to discuss the interactions among biological, ecological, chemical, and physical processes, and discuss what is known about nutrient inputs to the bay ecosystem, the impacts related to nutrient inputs, and how the ecosystem might respond to a sudden reduction in these inputs.