Concentration of Selected Heavy Metals in Sediments and Liver of Wild African Catfish (Clarias gariepinus) in Lake Kanyaboli, Kenya

It is evident that high heavy metal concentrations in sediments are eventually magnified along the aquatic lives like fish hence affecting human health. The present study therefore sought to determine the concentration of some heavy metals in sediments and liver of Wild African Catfish (Clarias gariepinus) in Lake Kanyaboli, Kenya. Fish were collected with the aid of a gill net of mesh size 4” and 5” whereas bottom sediments were collected by ErkMan crab sampler. The concentrations of Cadmium, Chromium, Zinc, Copper, and Lead in lake sediment and in the liver of Clariasgariepinus were determined using Flame Atomic Absorption Spectrophotometry (FAAS). Mean differences were determined using ANOVA and separation of means with Tukey’s test. Correlation analysis was done to determine the relationship of heavy metal contamination in sediments and fish liver. Obtained results showed that mean metal concentration in sediments were Cd (0.49 ± 0.02 - 0.77 ± 0.02), Cr (4.26 ± 0.015 - 7.48 ± 0.042), Zn (79.61 ± 0.57 - 87.09 ± 1.01), Cu (14.03 ± 0.05 - 20.43 ± 0.55) and Pb (14.38 ± 0.96 - 155.56 ± 0.21). Metals concentrations were significantly (p < 0.05) higher in station 2 than at the other stations. The mean heavy metal concentrations in Clarias gariepinus liver were Cd (nd- 0.22 ± 0.01), Cr (0.37 ± 0.01 - 1.67 ± 0.03), Zn (7.12 ± 0.03 - 13.40 ± 0.32), Cu (2.12 ± 0.12 - 4.16 ± 0.12) and Pb (1.63 ± 0.33 - 14.40 ± 0.58). Zn exhibited a significant difference between the stations. Pearson’s correlation coefficient revealed positive correlation between heavy metals in sediments and fish liver except for Pb - Cd (r = -0.638; p = 0.849), Pb - Zn (r = - 0418; p = 0.689) and Pb - Cu (r = -0.461). The study concluded that Lake Kanyaboli contained elevated levels of heavy metals probably due to anthropogenic activities. Consequently, activities that cause the contamination should be discouraged by the suitable governmental agencies.