Fresh water
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- Freshwater redirects here. For the village on the Isle of Wight, see Freshwater, Isle of Wight.
Fresh water is water that contains only minimal quantities of dissolved salts, especially sodium chloride, thus distinguishing it from sea water or brackish water. All fresh water ultimately comes from precipitation of atmospheric water vapor, reaching inland lakes, rivers, and groundwater bodies directly, or after melting of snow or ice (see hydrologic cycle).
Access to fresh water is a critical issue for the survival of many species, including humans, especially in desert or otherwise arid areas. See water resources.
Even on a ship or island in the ocean, there can be a "water shortage", which means a shortage of fresh water. Seawater is undrinkable directly.
Fish can only tolerate a range of sodium chloride concentrations in water. Most species cannot live in both fresh and salt water, though some species move between the two, in brackish water. Saltwater fish have access to an abundance of salt, and try to get as much salt out of their body as possible, while trying to keep the water. Freshwater fish do the opposite: they have too much water, and too little salt.ca:Aigua dolça da:Ferskvand de:Süßwasser et:Magevesi es:Agua dulce eo:Nesala akvo fr:Eau douce he:מים מתוקים lb:Séisswaasser nl:Zoetwater ja:淡水 no:Ferskvann nds:Seutwater pt:Água doce ru:Пресная вода simple:Fresh water sv:Sötvatten vi:Nước ngọt zh:淡水