ASSESSMENT OF WATER QUALITY PARAMETERS OF THE COASTAL WATERS OF RIVERS STATE, NIGERIA

Abstract

The study was conducted to determine some important physical and chemical parameters following mass fish kills in the coastal waters of Rivers State, Nigeria. Three locations were selected because they were among the affected areas. The measured parameters were water temperature, salinity, pH, dissolved oxygen (DO), alkalinity, nitrate (NO₃−), nitrite (NO₂ −), phosphate (PO₄), and sulphate (SO₄). Results revealed that the monthly mean values ranged from 26.90 to 33.3°C for temperature, 6.13 to 7.44 for pH, 15.01 to 18.61 mg/l for salinity, 49.2 mg/l to 69.2 mg/l for alkalinity, and 5.32 to 8.58 mg/l for dissolved oxygen. Further results revealed that nitrite and nitrate concentrations ranged from 0.51 to 0.69 mg/l and 0.57 to 1.13 mg/l, respectively. The ranges of phosphate and sulphate were 0.31–0.46 mg/l and 3.4–4.51 mg/l, respectively. The statistical analysis of the measured physicochemical parameters revealed significant seasonal fluctuations for temperature, DO, salinity, pH, alkalinity, nitrate, and PO₄ (p<0.05). There was a strong positive and significant correlation between temperature and nitrate (0.927, p<0.01) and sulphate (r = 0.894, p<0.05). Also, there was a strong positive and significant correlation between pH and sulphate (r = 0.898, p<0.05). Nitrite and phosphate have a strong positive relationship (r = 0.993, p< 0.01). Generally, all the measured parameters were either within or slightly above the permissible limits obtainable in the marine environment.