Hydrobiology is the science of life and life processes in water. It focuses on limnology and oceanography. Early days; hydrobiology focused on description of physical, chemical and biological aspects of the water bodies. Today, Hydrobiology study biology, physics, chemistry, ecology, hydrology, sociology/policy, and geology of freshwater and marine water. Also, hydrobiology deals with the details of various forms of aquatic life such as algae, zooplanktons, fishes and other groups of living organisms.