Limnology is the study of inland waters - lakes (fresh and saline), reservoirs, rivers, streams, wetlands and groundwater - as ecological systems interacting with their watersheds and the atmosphere. Limnological discipline integrates functional relationships of growth, adaptation, nutrient cycles and biological productivity with species composition, and describes and evaluates how physical, chemical and biological environments regulate these relationships.
The word limnology is derived from the Greek limne - marsh, pond and Latin limnaea - something relating to a marsh. Simply put, limnology is the study of the structural and functional relationships of inland water organisms, as their dynamic physical, chemical and biotic environments affect them.