Ecological effects of oil spill on water and sediment from two riverine communities in Warri, Nigeria

Abstract

The ecological effects of oil spill in the environment were studied in Warri riverine areas of Ubeji and Jeddo, Delta State, where an oil spill occurred and cleanup or remediation was not carried out for over a year prior to this evaluation. The American Public Health Association (APHA) and the American Society for Testing and Materials (ASTM) methods were employed for the laboratory test for organics [polyaromatic hydrocarbon; total petroleum hydrocarbon (TPH)] and heavy metals in the water and sediment. The results indicated that there were still significant  concentrations (P <0.05) of organics indicating hydrocarbon pollution. Mean  concentrations recorded for TPH in Ubeji and Jeddo waters were 23.60 ± 1.18 mg/L and 29.96 ± 0.14 mg/L respectively while total PAHs was 0.009 ± 0.002 mg/L and 0.008 ± 0.001 mg/L. Mean concentrations of TPH in the sediment was 48.83 ± 1.49 ppm and 1093 ± 74 ppm respectively while total PAHs was 0.012 ± 0.002 ppm and 0.026 ± 0.004 ppm. Low concentrations were recorded for most of the heavy metals in the water and sediment. Hydrocarbon degrading bacteria (HDB) recorded mean values of 3.86E + 03 and 3.44E + 02 for Ubeji and Jeddo waters, while Hydrocarbon degrading fungi (HDF) recorded mean values of 2.86E + 03
and 2.46E + 02 respectively. The observed concentrations of hydrocarbons in the study areas should provide the impetus for regulatory surveillance of oil discharged intentionally/unintentionally into the Warri riverine waters and sediment since hydrocarbon released into the environment sorb to the sediment particles where they cause harm to organisms in the sediment and overlying waters.

Keywords: Crude oil, oil spillage, PAHs, sediment, TPH, water.