The study of aquatic ecosystems and the organisms that inhabit them are studied in the two fields of aquatic ecology and biology. An aquatic ecosystem is a combination of various biotic communities and abiotic factors. Abiotic factors include parameters of water depth, nutrient level, salinity, temperature, etc. Maintenance of normal values of these variables is essential for the continued sustainability of the diverse flora and fauna of such ecosystems. Aquatic ecosystems are primarily grouped into marine and freshwater ecosystems, along with lentic, pond, lotic and wetlands forming other smaller classes. Aquatic ecosystems are crucial for the efficient recycling of nutrients, purification of water, ground water replenishment and in the provision of habitats to aquatic life. This book provides significant information on these disciplines to help develop a good understanding of aquatic biology and ecology and their related fields. It also includes some of the vital pieces of work being conducted across the world. This book is a vital tool for all researching or studying aquatic sciences as it gives incredible insights into the emerging trends and concepts