Physico-chemical parameters and nutrient salts were determined seasonally in water samples collected from 14 stations along the western side of the Gulf of Suez during the period from spring 2014 to winter 2015. The results indicated that, the annual mean range for the surface water samples collected from the north-western sector of the study area (water temperature, salinity, pH, dissolved oxygen, biological oxygen demand, nitrite, nitrate, ammonia and dissolved inorganic phosphate) were 18.40-30.10⁰C, 39.90-40.51 %₀, 8.08-8.39, 4.28-10.41 mgO₂L^-1,1.53-7.04 mgO₂L^-1, 0.77-2.82 µmolL^-1, 2.07-67.88 µmolL^-1, 3.24-43.15 µmolL^-1 and 0.93-3.45 µmolL^-1, respectively. The corresponding values for surface water samples collected from the south-western sector of the study area were 17.70-33.30⁰C, 40.45-40.88‰, 8.16-8.37, 4.36-10.71 mgO₂L^-1, 1.53-6.73 mgO₂L^-1, 1.12-2.53 µmolL^-1, 5.27-11.48 µmolL^-1, 1.94-10.80 µmolL^-1 and 1.87-4.77 µmolL^-1, respectively.
Generally, the present data indicated that the concentration of the measured Physico-chemical parameters were relatively high especially (the level of nutrient salts) at the north-western of the Gulf and decreased southward (Red Sea). This reflects high intensive disposal of sewage and industrial effluents in the north-western sector of the Gulf of Suez.
Seasonally, nutrient salts levels increased during spring and summer which may be attributed to increased human and industrial activities and disposal of treated and untreated sewage. Nutrient salts decreased during autumn, except for phosphate.
The annual average of N:P ratio was 10.83 for surface water samples in the north-western sector, while it was 4.68 in the south-western sector of the Gulf of Suez. The results of N:P ratio indicated that the north-western sector of the Gulf of Suez is in the eutrophic state, mainly due to the high load of nitrogenous compounds especially ammonia.
Results of the present study reflect that the north-western sector of study area adverse from high intensive disposal of sewage and industrial effluents.