Evaluation of the Acute Toxicity of Corexit 9527/Forcados Crude Oil Mixture on Tilapia Guineensis and Sarothedron Melanotheron

Abstract

Oil spills constitute enormous environmental problems and present significant threat to marine and shoreline ecosystems. This problem is compounded by the fact that the toxicity of dispersed oil has been shown to be greater than that of oil alone. This study evaluated the acute toxicity of Corexit 9527/Forcados (C/F) blend crude oil mixture to Sarothedron melanotheron (brackish water specie) and Tilapia guineensis (fresh water specie). Also the effects of the oil/dispersant mixture on the physicochemical parametres of fresh and brackish waters were assessed. Results showed that the oil/dispersant mixture remarkably influenced the physicochemical attributes of the dilution waters. The 96 h LC50 values estimated by the probit method were 62.15 and 45.63 litre−1 for the fresh and brackish water species respectively. The oil/dispersant mixture was more toxic to the brackish water specie as shown by the lower LC50 value and the greater variation in the physicochemical variables of brackish water.