Coastal Zones and Estuaries is a component of Encyclopedia of Environmental and Ecological Sciences, Engineering and Technology Resources which is part of the global Encyclopedia of Life Support Systems (EOLSS), an integrated compendium of twenty one Encyclopedias. The Theme deals with important links of water, sediment, and nutrients between continents and oceans. The present behavior of sea level, ice sheets, and coral reefs is still a matter of controversy and concern. Coastal experiences learned in developed countries should be used to improve coastal policies world wide. Within the Global Change Programme, it is recognized that the earth system is characterized by critical limits and abrupt changes. The coastal systems are particularly sensitive to these changes. This volume is aimed at the following five major target audiences: University and College Students, Educators, Professional Practitioners, Research Personnel and Policy Analysts, Managers, and Decision Makers and NGOs.