Spatial Variation in Physico-Chemical Parameters of Eastern Obolo Estuary, Niger Delta, Nigeria

Abstract

Aspects of the physicochemical parameters of Eastern Obolo estuary, Eastern Obolo, were investigated for three months at five locations: Okorombokho, Iko, Amadaka, Emereoke and Obianga.  Mean concentrations of some of the measured parameters at the five sampling locations showed significant statistical differences: Nickel (F = 18.48, df 2,8; P<0.001), Potassium (F = 4.47, df 2,8; P<0.05), Total dissolved solids (F = 32.26, df 4,8; P<0.001), pH (F = 21.55, df 4,9; P<0.001), Salinity (F = 73.15; df 4,8; P<0.001), Dissolved Oxygen (F = 5.06, df 2,8; P<0.05), Temperature (F = 10.96, df 2.8; P<0.01), and Conductivity (F = 71.94, df 4,8; P<0.01).  Mean differences of other parameters were not statistically significant.  The variability of the concentrations of the parameters during the period of study was lowest for dissolved oxygen (2.2%) and highest for hardness (68.4%).  The availability of nickel in these waters indicated crude oil pollution. The mean values of nickel, potassium, total dissolved solids, sodium, copper, zinc, total hydrocarbons and biochemical oxygen demand from all stations exceeded the recommended limits for aquatic life or potable water. Hence, the Eastern Obolo estuary may not be an efficient source of drinking water for the community but it definitely helps flush out anthropogenic pollutants into the sea.

Keywords: estuarine flushing, nickel, potassium, total dissolved solids, sodium, copper, zinc, total hydrocarbons