Brackish water
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Brackish water is water that is saltier than fresh water, but not as salty as sea water. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur naturally, as in brackish fossil aquifers. Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (ppt or ‰). Thus, brackish covers a range of salinity regimes and is not considered a precisely defined condition. It is characteristic of many brackish surface waters that their salinity can vary considerably over space and/or time.
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Etymology
The term brackish water derives from the Low Saxon word brackwater, which is the water of a brack. A brack is a small lake created when a storm tide breaks a dike and floods land behind the dike.
Brackish water aquaria
Keeping brackish water aquaria is a popular specialization within the fishkeeping hobby. Many species of fish traded as freshwater species actually do better in brackish water, for example black mollies, Florida flagfish, and some cichlids such as orange chromides. There are also several popular species traded purely as brackish water fish, including Monodactylus spp, scats, archerfish, and various species of pufferfish, goby, and flatfish. Generally aquarists need to maintain a specific gravity of around 1.005 to 1.010 depending on the species being kept, but practically all brackish water fish tolerate variations in salinity well, and some aquarists maintain that regularly fluctuating the salinity in the aquarium actually keeps the fish healthy and free of parasites.
Brackish bodies of water
- Baltic sea
- Chilka Lake, in Orissa state, India
- Hampton Roads, Virginia, USA
- Kaliveli Lake, near Pondichery, India
- Lingding Yang, Guangdong, China
- Pangong Tso in Ladakh, Jammu and Kashmir state, India
- Lake Pontchartrain, north of New Orleans, Louisiana, USA
- Pulicat Lake, north of Chennai, India
- The Rann of Kutch, on the border of India and Pakistan
- Parts of the Rhone Delta, France: An area known as the Camargue.
- The River Thames at London
- The Chesapeake Bay, in Maryland, USA.
See also
Permian Sea (underwater basin and remnant of the ancient Permian Ocean) extending underground from Eastern New Mexico (USA) to West Texas
External links
- Brackish Water Aquarium FAQ (http://homepage.mac.com/nmonks/aquaria/brackfaqpart1int.html)da:Brakvand
de:Brackwasser et:Riimvesi nl:Brakwater nds:Brackwater pt:Salobra fi:Murtovesi sv:Bräckt vatten