Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Low German root "brak," meaning "salty". Certain human activities can produce brackish water, in particular certain civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms).

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.

Notable brackish bodies of water (by type, in alphabetical order)[link]

Brackish seas

Map of the Baltic Sea

• Baltic Sea (the world’s largest pool of brackish water)
• Black Sea

Brackish water lakes

Map of Lake Chilka, India's largest lake, classified as a brackish water body

• Caspian Sea (world’s largest lake)
• Lake Charles in Lake Charles, Louisiana, the United States
• Chilka Lake in Orissa, India
• Issyk Kul in Kyrgyzstan
• Laguna de Oviedo in the Dominican Republic
• Lake Maracaibo in Zulia State, Venezuela
• Lake Monroe in Florida, the United States
• Pangong Tso in Ladakh, Jammu and Kashmir, India
• Lake Van
• Lake Mogil'noe on Kildin Island, north of Murmansk, Russia

Lochs (Scottish)

• Loch Long
• Loch of Stenness
• Loch Bee
• Loch Obisary
• Loch an Duin
• Loch Scavaig

Coastal lagoons, marshes, and deltas

• The Burgas Lakes near the Bulgarian Black Sea Coast
• The Fleet lagoon in Dorset, England, the United Kingdom
• Kaliveli Lake in Tamil Nadu, India
• The Kerala Backwaters, a series of lagoons and lakes in Kerala, India
• Lagos Lagoon in Lagos, Nigeria
• Lake Pontchartrain in New Orleans, Louisiana, United States
• Pulicat Lake, north of Chennai, India
• The Rann of Kutch on the border of India and Pakistan
• Parts of the Rhône Delta, France: An area known as the Camargue
• Widewater, and land-locked lagoon near Lancing, England

Estuaries

• Amazon River, empties so much freshwater into the Atlantic Ocean that it reduces the salinity of the sea for hundreds of miles
• Chesapeake Bay in Maryland and Virginia. It is the drowned river valley of the Susquehanna River. It is the largest estuary in the United States.
• Delaware Bay, an extension of the Delaware River in New Jersey and Delaware, the United States
• The Lower Hudson River in New York and New Jersey, the United States
• East River and Harlem River in New York, the United States
• Lingding Yang, Guangdong, China
• Port Royal Sound in Beaufort County, South Carolina, the United States
• Puget Sound in Washington State, the United States
• Río de la Plata in Argentina and Uruguay.^[1]
• Saint Lawrence and Saguenay Rivers, the part downstream from Quebec City and Saguenay respectively, Canada
• San Francisco Bay and San Pablo Bay adjacent to San Francisco in California, United States
• The Thames Estuary in South East England, United Kingdom

See also[link]

• Biosalinity
• Brackish water aquarium
• Desalination

References[link]

Further reading[link]

• Moustakas, A. & I. Karakassis. How diverse is aquatic biodiversity research?, Aquatic Ecology, 39, 367-375