Metal Levels in the Liver, Muscle, Gill, Intestine, and Gonad of Lake Van Fish (Chalcalburnus Tarichi) With Abnormal Gonad

Abstract

Recently, an increasing number of studies have shown that Lake Van-the biggest soda lake in the world-is polluted due to an increasing population. Studies have shown abnormalities in the Lake Van fish (Chalcalburnus tarichi), the sole fish species that inhabits the lake. Unlike the vitellogenic and mature oocytes in normal gonads, abnormal gonads show large amounts of connective tissue and young oocytes. In this study, metal levels (nickel [Ni], copper [Cu], cobalt [Co], iron [Fe], zinc [Zn], cadmium [Cd], lead [Pb], and manganese [Mn]) in the muscle, liver, gill, intestine, and gonad of Lake Van fish with normal and abnormal gonads were assessed. Further, the metal contents in the wastewater from the wastewater treatment facility situated near Lake Van in Van City were assessed. All the metal levels, except that of Zn, were high in the Lake Van environment (P < 0.05). The highest metal content in the tissues was for Fe, while the lowest level was for Co. The Pb level was found to be very high in both fish groups. Cd was not found in the tissues of both fish groups. The levels of Fe, Cu, Pb, and Mn were not significant in the tissues of both normal and abnormal fish groups. Zn level was significantly high in the livers and gonads of fish with abnormal gonads, and Co level was significantly high only in the livers (P < 0.05). Consequently, high levels of Zn in the liver and gonads and high levels of Co in the liver may be factors causing the abnormal gonads in the Lake Van fish.