Aquatic ecology refers to the ecosystem that is present within a particular water body. This book explores various aquatic ecologies and their relation to Earth’s ecosystem in the larger context. It strives to provide a fair idea about this discipline and help develop a better understanding of the emerging concepts and issues within this field with topics such as climate change, marine biology and biodiversity, biogeochemistry, etc. This book is an essential guide for both academicians and those who wish to pursue this discipline further.