Seasonal Variations of the Physical and Chemical Properties of Seawater at the Northern Red Sea, Egypt

The present study focused on the seasonal variations of physical and chemical properties of seawater at the Northern Red Sea coast. The results showed good quality of water of the area of study in general. Seasonal variations of physico-chemical parameters such as water temperature, pH, salinity, dissolved oxygen (DO) and the biological oxygen demand (BOD) were investigated and showed a range of 17.96 0.06 to 32.56 0.25 ˚ C for temperature, 7.78 0.01 to 8.21 0.02 for pH, 40.02 0.11 to 42.32 0.10‰ for salinity, 6.05 0.21mgl 1 to 8.05 0.12 mgl 1 for DO and 0.73 0.20 to 4.15 0.22 mgl 1 for BOD at different sites during the different seasons. The physico-chemical parameters have exhibited slightly seasonal variations at different sites of the present study area. Nutrients concentrations were very low at the different sites and showed an increase at site III. The ranges of ammonia, nitrite, nitrate, phosphate and silicate were: (1.93 0.11 to 14.31 2.11 mMl 1 ), (0.03 0.01 to 1.30 0.18 mMl 1 ), (0.15 0.05 to 4.88 2.25 mMl 1 ), (0.03 0.01 to 0.49 0.10 mMl 1 ) and (0.48 0.04 to 2.85 0.14 mMl 1 ) respectively, at the study area