Limnology: It is the study of organisms present in rivers or fresh water lakes. Limnology is also called as freshwater science. This is the study of inland waters. Limnology is often regarded as a division of  environmental science and ecology. It covers the chemical,  physical, biological, geological or other attributes of all inland waters like running or standing waters, both fresh & saline, natural or man-made.

Limnology includes the study of ponds or lakes, streams,  rivers, springs or wetlands.  A more recent sub-discipline of limnology is called as landscape limnology. This study manages or conserves these aquatic ecosystems using a landscape perspective. Limnology is related to hydrobiology or aquatic ecology, in which aquatic organisms in particular regard to their hydrological environment are studied.