This book describes critical environmental issues that face coastal ocean and Great Lakes areas, including eutrophication, habitat modification, hydrologic and hydrodynamic disruption, exploitation of resources, toxic effects on ecosystems and humans, introduction of nonindigenous species, global climate change and variability, and shoreline erosion and hazardous storms. These issues can be approached through science activities (including research, monitoring, and modeling) discussed in this book and through coordination among federal agencies.