The importance and ecological significance of estuaries has been long appreciated. In the last few years, there has been increased research activity, resulting in significant advances in understanding of estuarine ecology. This special thematic volume of Advances in Ecological Research provides an overview of a number of the important areas. Ranging from the macroscale: how differences in river basins influence the loads of nutrients, through the impacts and fates of the nutrient loads, to how both phytoplanktonic and benthic estuarine primary production are regulated. There is also a review of the key factors influencing the outcome of management decisions for estuaries from the point of sustainability of estuarine resources. This volume is essential reading and reference for all those interested in estuaries including ecologists, environmental scientists, botanists, and zoologists.