Influence of Tide and Season On The Physicochemical Parameters of Calabar River Estuary, Nigeria.
The influence of tides on the concentrations of magnesium, silicate, BOD, COD, DO, nitrite nitrate, sulphate, phosphate temperature, salinity turbidity, pH and conductivity in the Calabar river estuary was investigated during the rainy season ( July – October). Results are distributed as follows: Conductivity (26-42 µS/cm), Temperature (25.2-27.3oC), pH (4.69-7.70), turbidity (14-41 FTU), DO (4.8-7.0 mg/l), BOD5 (0.4-1.5 mg/l), Mg (0-19.42 mg/l), Sulphate (1.36-4.75 mg/l), ammonium (0.06-1.36 mg/l), nitrite (0-0.004 mg/l), nitrate (0.08-0.99 mg/l), phosphate (0-0.017 mg/l) and silicate (0.05-0.46 mg/l). Wide variations were observed between high and low tides and neap and spring tides as well as between months which were attributed to tidal resuspension of materials from sediments and terrestrial/rain related input of materials. All concentrations were within range of values for similar tidal systems in Nigeria and those of earlier studies in the river system.