摘要
People tend to rely upon fish as a source of cheap animal protein and a vital resource to sustain life.Oreochromis niloticus(tilapia fish)and Clarias gariepinus(cat fish)were collected from two rivers(Nworie and Otamiri rivers)and two fish ponds(FUTO and Philip’s fish ponds in Owerri municipal).The heavy metals analyzed were mercury(Hg),cadmium(Cd),iron(Fe),nickel(Ni),zinc(Zn),lead(Pb),and chromium(Cr)using FS 240 Varianatomic absorption spectrophotometer(AAS)SpectrAA.Catfish accumulated high level of Hg concentrations(>1.40 ppm)in the sample sites,Cd concentration was also high in cat fish(8.33 ppm)sampled from Nworie river while the other sample sites recorded<1 ppm.Also,Fe recorded concentrations above 4 ppm with highest concentration of 30.8 ppm;however,tilapia fish accumulated more Fe concentrations than the cat fish.Heavy metals values in the fishes were above the maximum permissible limits of established standards for fish consumption.Data collected were subjected to t-test and analysis of variance(ANOVA),and there was no statistical difference(p>0.05)between the heavy metals contents of fishes from the rivers and fish ponds studied.The total heavy metals concentrations studied accumulated from the different sample sites were in this order:tilapia fish:Nworie river(5.96±4.36)>Otamiri river(4.87±3.32)>Philip’s pond(4.87±3.19)>FUTO pond(1.62±1.40)while in cat fish:Nworie river(4.02±1.66)>Philip’s pond(3.60±2.10)>Otamiri river(2.43±1.54)>FUTO pond(2.27±1.38).There is need for periodic monitoring and assessment of heavy metals in water bodies and various aquatic lives that serve as a source of food to human.
