NEET BIOLOGY

Detailed explanation-1: -Freshwater has very little salt, usually less than 0.5 ppt. Water with a salinity of 0.5-17 ppt is called brackish water, which is found in estuaries and coastal salt marshes.

Detailed explanation-2: -Places of lower salinity Seawater can also be less saline near land, where rivers add freshwater. The ocean around Antarctica has a low salinity of just below 34 ppt, and around the Arctic it is down to 30 ppt in places.

Detailed explanation-3: -Fresh water-Less than 1, 000 ppm. Slightly saline water-From 1, 000 ppm to 3, 000 ppm. Moderately saline water-From 3, 000 ppm to 10, 000 ppm. Highly saline water-From 10, 000 ppm to 35, 000 ppm.

Detailed explanation-4: -Freshwater: Less than 1, 000 parts per million (ppm) Slightly saline water: 1, 000 ppm – 3, 000 ppm. Moderately saline water: 3, 000 ppm – 10, 000 ppm. Highly saline water: 10, 000 ppm – 35, 000 ppm.

Detailed explanation-5: -Salinity in inland waters may be defined either as primary salinity – where the salinity is natural due either to sources of salt in watersheds or to high evaporation rates, or both – or secondary salinity where the salinity has arisen or increased due to human activity in the watershed (Williams, 1999).