Heavy Metal Analysis in Silver Catfish (Chrysichthys nigrodigitatus) from Asejire and Erinle Reservoirs in Southwest Nigeria

Background and Objective: Fish tend to accumulate heavy metals from the aquatic ecosystem due to their high trophic position in the food chain. This study was carried out to analyse the concentration of some heavy metals in selected organs of Chrysichthys nigrodigitatus collected from Asejire and Erinle Reservoirs. Materials and Methods: Measurements of eight morphometric characters were recorded for fish samples from Asejire and Erinle Reservoirs. Heavy metals in the fish and water samples were analysed using atomic absorption spectrophotometer. Results: There was a positive correlation between the weight and standard length of the C. nigrodigitatus samples from Asejire and Erinle Reservoirs. The liver accumulated the highest level of heavy metals while the muscle had the least bioaccumulation level. A correlation coefficient was observed between fish size and heavy metal concentration in fish. The level of heavy metals in C. nigrodigitatus samples from Asejire and Erinle Reservoirs exceeded the safe limit recommended by World Health Organisation (WHO). The water samples had levels of heavy metals within the tolerable range set by WHO. Conclusion: Therefore, it is necessary to continuously examine heavy metals in Asejire and Erinle Reservoirs since the reservoirs and their biota serve the surrounding towns.