This book provides a comprehensive overview of recent research on estuaries of the east coast of India, and how changing biogeochemical dynamics as a result of climate change and human activity have impacted estuaries and other open water ecosystems. Though estuaries only cover a very small portion of the earth's hydrosphere, they are some of the most biogeochemically active regions among the global water bodies. As such, this book focuses on estuaries of the east coast of India going all the way to the Bay of Bengal, which is the world's largest freshwater input from perennial rivers and rain-fed estuaries, and is therefore a unique area of study. Through its unique coverage of the Bay of Bengal in particular, the book presents a new perspective not present in the literature on estuary biogeochemistry and ecosystem dynamics. Moreover, the book addresses SDG 13 (Climate Action) and 14 (Life below Water), with a focus on ecosystem services of the natural aquatic system.The book will be useful to researchers, policy makers, coastal managers and marine sustainability scientists and organizations.