Physico-chemical characteristics of different water types in El-Mex Bay, Alexandria, Egypt

A comprehensive environmental study was carried out in four seasons (summer, autumn, winter, and spring) through 2003-2004 for evaluating the effect of contamination with different types of pollutants sewage, agricultural and industrial wastes discharged into El-Mex Bay on its water quality. Temperature, salinity, pH, dissolved oxygen, Nutrient salts (NH/sub 3/, NO/sub 2/, NO/sub 3/, PO/sub 4/, SiO/sub 4/) and major constituent of sea water (Ca, Mg, Na, K) are measured at both surface and bottom water at 12 stations representing the bay. El-Mex Bay is characterized by the presence of two water layers overlying each other, an upper brackish layer and a lower diluted sea water layer. Surface layer is specified into three different water types according to salinity values: (i) water type "L" land drainage waste water with salinity<10, (ii) water type "M" "mixed sea water with land drainage" with 10