Water Salinity

Salinity is commonly called the salinity is the total amount of material dissolved in water. Generally, salinity was calculated with units of ppt (parts per thousand), ie the amount of material (grams) of solute per liter of water.

Based on salinity, water bodies can be divided into three categories, namely freshwater (0-3ppt), seawater (greater than 20 ppt) and brackish water (40-20 ppt). In normal sea water salinity is 35 ppt, although it will vary depending on the location.

To measure the salinity can be done by means of salinometer or a refractometer. By way of dripping water into the tool, then the value of salinity is the amount of water that dripped, can be read on the scale tool.

Effect of salinity of fish occur on osmoregulation process. Freshwater fish are not tolerant of salinity, due to changes in physiology osmosecells of the body that cause fish become stressed.

Tolerance to salinity by fish from the brackish water areas are generally higher or wider than freshwater fish or saltwater fish. Such as scat fish (Scatophagus argus), some of rainbow fish, and Blue Acara (acqudens Pulcher) quite tolerant with fresh water to brackish water.