Determination of the Concentration of Arsenic, Cadmium and Nickel in Tilapia Fish (Oreochromis Niloticus) in Gyawana Aquatic Ecosystem

Study on the mean concentration of arsenic, cadmium and nickel (heavy metals) in organ and tissue of tilapia fish (Oreochromis niloticus) in Gyawana aquatic ecosystem, Lamurde Local Government Area of Adamawa State, Nigeria, was carried out. The results showed that nickel and cadmium were detected in the flesh, liver and the blood tissue of the fish, while arsenic was not detected. The mean concentration of nickel was highest in the flesh (0.025±0.002mg/g), followed by liver (0.014±0.001mg/g) and the lowest was detected in the blood (0.005±0.001 mg/g). Similarly, cadmium was higher in the flesh (0.029±0.003mg/g), followed by the liver (0.023±0.002mg/g) and the least was found in the blood (0.008±0.000mg/g). The result also reveals that male O. niloticus has higher mean concentration of these heavy metals than female O. niloticus. Nickel means concentration was slightly higher in male O. niloticus (0.016±0.009 mg/g) than in female O. niloticus (0.013±0.007mg/g). The mean concentration of cadmium was also higher in male fish with 0.021±0.010mg/g than female tilapia fish that has 0.018 ±0.008mg/g. Throughout the study period arsenic was not detected in any organ nor blood tissue of tilapia fish (Oreochromis niloticus). In conclusion, Gyawana aquatic ecosystem, cadmium and nickel were detected in both flesh and blood of O. niloticus, while arsenic was not detected at all. Male O. niloticus have higher mean concentration of cadmium and nickel than female O. niloticus. Based on the findings of this study, the researcher therefor recommends that dumping of waste and effluent in water bodies should be discourage, so that the aquatic ecosystem should be free from contaminant with heavy metals.