Assessment Of Heavy Metals (Al, Zn, Cu, Cd, Pb And Hg) In Demersal Fishes Of Kuala Tanjung Coast, North Sumatra


The presence of heavy metals in aquatic environment has been of great concern because of their toxicity when their concentration is more than the permissible level. This study was carried out to assess concentrations of six heavy metals (Al, Zn, Cu, Cd, Pb and Hg) in the muscle and liver of Chiloscyllium punctatum, Chiloscyllium indicum, Johnius belangeri, Nibea soldado, Otolithes ruber, Paratrypauchen microcephalus, Cynoglossus lingua, and Cynoglossus puncticeps from Kuala Tanjung coastal waters. The levels of Al, Zn, Cu, Cd and Pb were measured by Graphite Furnace Atomic Absorption Spectroscopy (GFAAS) technique; whereas Hg was measured by Cold Vapour Atomic Fluorescence Spectroscopy (CV-AFS) technique. The bioaccumulation of Al, Zn and Cu was predominant followed by Cd, Pb and Hg both in muscle and liver tissue of fish sample. The concentration range of Al, Zn, Cu, Cd, Pb and Hg in muscle was 0.01-16.9, 2.97-11.5, 0.01-0.37, 0.001-6.400, <LD-0.04 and 0.002-0.047 wet weight respectively; whereas in liver was 0.25-503, 6.04-9.98, 0.28-5.20, 0.005-0.1800, <LD-0.10 and 0.008-0.030 wet weight respectively. J. belangeri and O. ruber accumulated the highest levels of Al, Zn and Hg; while the highest levels of Cu, Cd and Pb were detected in C. indicum and C. punctatum. One-way analysis of variance (ANOVA) clearly revealed that there was a significant variation (p < 0.05) of the heavy metal concentrations in different fish species. Overall, the concentrations of the studied heavy metals, except Al & Cd were found to be below the safe limits suggested by various authorities. The results indicate that relatively high concentrations of heavy metals were found in liver of the examined species, which suggest the possibility of using this organ as bioindicator of metals present in the surrounding of Kuala Tanjung coastal waters



heavy metal, fish tissue, bioaccumulation, demersal fishes, Kuala Tanjung