Freshwater or (the predominant nontechnical spelling) fresh water is naturally occurring water on the Earth's surface in bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Freshwater is characterized by having low concentrations of dissolved salts and other total dissolved solids. The term specifically excludes seawater and brackish water. Systems Scientifically, freshwater habitats are divided into lentic systems, which are the stillwate… (More on Freshwater)