Because sea water contain many salts (especially NaCl) and other impurities, dissolved or suspended.
Fresh water - sea water kills.
A gallon of fresh water is heavier than a gallon of sea water because fresh water is denser than sea water.
Sea water is salt water.
Put it in the sea.
Fresh water...
Fresh water animals.
Salt water is denser than fresh water.
33 feet in sea water, 34 feet in fresh water
The bering sea is salt water.
Icebergs are made of fresh water.
salt water has salinity while fresh water does not
Fresh water fish do not drink water, they absorbed it through their skin, like osmosis. Sea water fish do drink water, and excrete the salt through their gills. The salmon, which lives in both in environments, gets its water like a fresh water fish when in fresh water and like a sea water fish when in the sea.