Impact Of Crude Oil On Recruitment Of Epibenthic Organisms In Cross River Estuary, South East Nigeria

Abstract

Effects of crude oil on recruitment of epibenthic organisms in Cross River estuary were studied in February and March, 2007 on wooden Panels (15×15×1.5cm). The panels were immersed in Nigerian light crude oil and later suspended in the estuary for six weeks. Rhizoclonium hieroglyphicum showed slight resistance to the effect of the crudeoil while species like Balanus balanoide, Crassostrea gazar, Bugula neritina, Serbellaria intoshi, Catenella opuntia and Caloglossa leprieurii showed slight inhibition. Statistically, there was however no significant difference in the recruitment level of the organisms on both the control panels and oil-polluted panels, (p>0.05). This may probably have been as a result of weathering process or bacterial degradation of the crude oil which rapidly diluted the hydrocarbon, thereby reducing its toxicity. The result reveals that widespread oil spill during the reproductive season would reduce larval settlement and impede subsequent recruitment. The ecological implications of these findings are
discussed.