The Effect of Petroleum and Some of Its Products on the Mortality Rate of Fingerlings of African Catfish: A Case Study on the Effect of Pollution on Ecological Conservation

Aquatic pollution is of significant importance to fisheries and other aquacultural practises. It is therefore important to understand pollution effects on the conservation of aquatic organisms.The toxicity of Bonny Light crude oil (BLCO) and some of its products to fingerlings of Heterobranchus bidorsalis, a fresh water species was investigated at an average temperature of 27⁰C±2.5⁰C under laboratory conditions. Results gave an estimate of the effects as regards to mortality a stated quantity of oil can impart on fishes in a water body. The mortality increased from 50% at 0.2% concentration to 85% at 0.8% conecntration of diesel, 60% at 0.2% concentration to 100% before maximum time limit at 0.2% concentration of petrol. Fingerlings in crude oil show negligible mortality at 0.8% conecntration but show noticeable mortality at 5% conecntration and above. LT₅₀ increased from 10hrs at 0.8% concentration of petrol (PMS), 30hrs 0.8% conecntration of kerosene (DPK) to 34hrs 0.8% conecntration of diesel (AGO). The median concentration (LC₅₀) for 24, 48 and 72hrs were 1.11, 0.4 and 0.2 respectively for diesel; 1.08, 0.2 and 0.18 respectively for kerosene; 0.19, 0.1 and 0.09 respectively for petrol. LC₅₀ values show that H. bidorsalis are more resistant to diesel and kerosene than petrol.