The Estuarine Ecological Knowledge Network (EEKN) brings together scientists and coastal fishing communities in seeking new ways forward for Earth's major river deltas and estuaries, including the Mississippi (United States), Rio Grande (United States), Danube (Romania/Ukraine), Ganges (India/Bangladesh), Niger (Nigeria), and Mekong (Vietnam) river deltas, and the Patos Lagoon (Brazil). Such environments are universally understood as crucial for the biological productivity of oceans and they are home to hundreds of millions of human inhabitants, many of whom directly depend on that marine richness in terms of the operation of their socioeconomic systems. As human-induced climate change and its consequences for Earth's oceans and coastlines increases, estuarine ecosystems are particularly threatened by problems such as sea-level rise, coastal erosion, saltwater intrusion, and increased impacts from tropical storms. These problems are often amplified by human dynamics of environmental degradation, including overfishing, pollution, and large-scale landscape modification projects. The EEKN is designed to enhance communication and cooperation between fishing communities, scientists, and policy makers in learning about the complexity of both ecological and socioeconomic systems in estuaries and deltas, and in developing more effective policy for managing fisheries, protecting and restoring coastlines, and increasing the resilience of coastal communities.