The effect of seasonal variation and lipid content on polychlorinated biphenyls and organochlorine accumulation in Spot Barb (Puntius bimaculatus)

Abstract

After they reach an aquatic environment, polychlorinated biphenyls (PCBs) and organochlorine (OC) tends to accumulate in organisms, because of their high hydrophobic property which then causes adverse effects. However, there are some factors that have an influence on the accumulation. The aim of this study was to investigate the effect of seasonal variation and lipid content on PCBs and OC accumulation. Spot barb (Puntius bimaculatus) was selected as the representative of aquatic organisms because it is widely found across the country. Nine sampling stations located along the river receiving wastewater from surrounding farms, domestic, and industrial areas. Twenty fish (in each station) were collected by using floating nets in both dry and wet seasons for measurement of PCBs and OC in the samples. The results indicated that both PCBs and OC concentration in fish collected in the dry season was higher than that in the wet season. These findings could be explained by the characteristics of water channels in the dry season which are quite stagnant, resulting in toxicants being adsorbed onto organic matter surface and then becoming feed for the fish. For the effects of lipid content, the results showed that PCBs/OC concentrations and lipid content were of significant positive correlation (p ≤ 0.05) in both dry and wet seasons. This phenomenon might be the result of hydrophobic property of toxicants which make it accumulate in lipid tissue.