Brackish water
Topic: Oceans: Hydrological Cycle, Relief of the Ocean Floor, Temperature and Salinity · NCERT: Class 11, Ch 12 "Water (Oceans)"
Meaning
Brackish water is saltier than fresh water but less salty than seawater. NCERT takes 24.7‰ (parts per thousand) as its upper limit. It forms where river water mixes with seawater, or where a sea gets plenty of fresh water but has only a narrow link to the ocean. Brackish waters are important nurseries for fish, prawns and crabs.
Example
Chilika Lake on the Odisha coast is a brackish lagoon, which means a shallow body of water partly cut off from the sea. Another is Pulicat Lake on the Andhra Pradesh–Tamil Nadu border. The Baltic Sea in northern Europe is a whole sea of brackish water.
Don't confuse with
- Hypersaline water: this water is much saltier than normal seawater. Examples are hot, dry lagoons that reach about 70‰ and the Dead Sea. Brackish water is less salty than the sea.