Effects of Varied Concentrations of Automotive Gas Oil Pollution on Performance of Clarias gariepinus

Abstract

Water pollution, which is sometimes caused by the spilling of commercial petroleum fuels (CPFs), is a major environmental problem that causes toxic effects in aquatic ecosystems. Hence the effect of varied concentrations of Automotive Gas Oil (AGO) pollution on Clarias gariepinus was investigated. 210 juveniles of C. gariepinus (mean juvenile weight of 3.3g) were divided into five treatment groups of 42 each and assigned to different pollution levels (treatments) of AGO in a laboratory condition for a period of 14 days. Each treatment was replicated three times composed of 14 juveniles of C. gariepinus in each replicate. 20 liters de –chlorinated bore hole water was poured into the each of the 15 plastic aquaria (experimental units) and AGO was introduced to the water at 0mg/l (control), 5mg/l, 10mg/l, 15mg/l, or 20mg/l, as single treatments. The effect of exposure to AGO pollution levels on rate of survival/mortality, growth rate and nutrient utilization of juveniles were investigated. Data collected were subjected to analysis of variance (ANOVA) and test of significance was by Duncan Multiple Range Test. From the results there was no mortality recorded for fish exposed to all treatments regardless of pollution levels; but AGO pollution levels, significantly affected fish growth and nutrient utilization (P<0.05). Fish growth reduced with increased AGO pollution level. The study concluded that C. gariepinus is an effective bio-indicator for AGO polluted aquatic environment; Maximum Admissible Concentration (MAC) of AGO in water bodies for optimal performance of C. gariepinus is less than 5mg/l, yet the study showed that even 5mg/l AGO pollution negatively affected growth of the specie.