This book provides comprehensive coverage of the fundamental principles and current practices and trends in the field of conservation of freshwater ecosystems, Aquatic Ecology, Limnology and fishery science. This book updates the subject matter, illustrations and problems to incorporate new concepts and issues related to Aquatic Ecology, Limnology and fishery science. The book includes chapters contributed by outstanding scholars and scientists from different institutions. We hope this book will provide a multi-disciplinary forum to explore emerging areas in the field of Aquatic Ecology, Limnology, freshwater ecology and fishery science.