Evaluation of toxicological impact of Nigerian crude oil (Bonny Light) to <i>Tilapia guineensis</i>

Abstract

The acute toxicity of Nigerian crude oil (Bonny Light) to Tilapia guineensis was assessed in a static renewal bioassay for 96 hours. Five concentrations of the crude oil were prepared as 40, 80, 160, 240 and 320 Mg/l and a control experiment (0 Mg/l). The median lethal concentration (LC50) at 24-hr, 48-hr, 72-hr and 96-hr was 0, 281.84, 316.23 and 125.89 Mg/l respectively. The median lethal time (LT50) at crude oil concentrations of 160 Mg/l, 240 Mg/l and 320 Mg/l were 92hrs, 82hrs and 49hrs respectively while the LT50 at concentrations of 40 Mg/l and 80 Mg/l was 0hr. The minimum concentration of Bonny light crude oil that can cause the death of T. guineensis was 323.59Mg/l and the minimum time that this concentration can cause the death of T. guineensis was 92hrs. Mortality increased with increase in crude oil concentration and the difference was significant (p<0.05).

Keywords: Toxicity, Tilapia guineensis, LC50, LT50, Bonny Light crude oil.