Introduction Salinity is the measure of the amount of dissolved salts in water. It is usually expressed in parts per thousand (ppt) or percentage (%). Freshwater from rivers has a salinity value of 0.5ppt or less. Within the estuary, salinity levels are referred to as oligohaline (0.5-5.0 ppt), mesohaline (5.0-18.0 ppt), or polyhaline (18.0-30.0 ppt). Near the connection with the open sea, estuarine waters may be euhaline, where salinity levels are the same as the ocean at more than 30.0 ppt. 1 Salinity varies from place to place in the oceans, but the relative proportions of the most major dissolved constituents remain virtually constant. Even though there are smaller quantities of other ions in seawater (e.g., K + , Mg 2+ , SO 4 2- ), sodium (Na + ) and chloride (Cl - ) ions r

Join for free to read