Toxicity effect of bonny light crude oil on tadpole from Badore, Lagos State, Nigeria

Abstract

Toxicity of crude oil on aquatic organism with concentration of hydrocarbon mixture can result in mortality during designated exposure period. This study was carried out in Badore Experimental Fish Farm Lagos. Bonny- Light Crude oil was obtained from Chevron Nigeria Limited, Lagos. The Tadpole collected were acclimated in 500 litre plastic tank for 10 days with Temperature range from 23^oC- 27^oC, pH of 8.6 and dissolved oxygen of 4.5mg/l. Ten (10) frog tadpoles in each concentration were stocked in three replicates with three concentrations (0.05ml/L, 0.10 ml/L,0.20 ml/L) and 0.00 ml/L as control. The initial weight range was 0.14 - 0.24g while after 96 Hrs weight range was 0.16 - 0.18g for 0.05 ml/L, 0.14 -0.19g for 0.10 ml/L, 0.08 -0.15g for 0.20 ml/L and control 0.00 ml/L was 0.21- 0.24g. The concentration mortality-survival relationship showed high significance (p<0.05); the coefficient of determination for log-concentration and probit was positive (r²=0.7011). Total mortality observed during the period was 27. This suggests that Bonny-Light Crude oil water soluble fraction is toxic to Rana temporaria tadpoles. At 5%, 10% and 20% WSF inclusion levels mortality was 10%, 36.67% and 43.33% during the experiment. Crude oil effluent should be properly disposed for effective safeguard of our ecosystems in Nigeria.