oligohaline

Oligohaline refers to a specific range of salinity in water bodies. It describes waters that have a low salt concentration, typically between 0.5 and 17 parts per thousand (ppt). This salinity level is higher than freshwater (which has less than 0.5 ppt) but significantly lower than brackish water in general or seawater.

Waters that are oligohaline are often found in transitional zones between freshwater sources, such as rivers, and more saline environments like estuaries or the sea. They can also occur in certain inland lakes, lagoons, or marshes where evaporation and freshwater inflow are balanced to maintain this intermediate salinity.

The oligohaline environment supports a unique community of aquatic organisms that are adapted to tolerate these fluctuating and relatively low salt levels. Many species found in oligohaline waters can survive in both slightly fresher and slightly saltier conditions. This makes these zones important for biodiversity and as nursery grounds for various fish and invertebrate species. The specific salinity within the oligohaline range can vary seasonally due to rainfall, snowmelt, or tidal influences.