Determination of Heavy Metals and Hemato-Biochemical Profiling of Bagre marinus and Bagarius bagarius in Jhelum River

Abstract

Heavy metals enter river basins through industrial effluents, agricultural wastes, surface run-offs, and other human activities, negatively impacting aquatic and terrestrial life by bioaccumulating in the food chain. This problem is on a continuous rise in under-developed and developing countries, such as in Pakistan. Therefore, the current study was aimed to determine concentrations of heavy metals, essential trace elements, and macrominerals (Zn, Pb, Ni, Mn, Mg, Fe, Cu, Cr, Co, Cd, Ca, and As) in the water, sediments, and tissues (gills, liver, and muscles) of Bagarius bagarius and Bagre marinus in the Jhelum River, Pakistan. The hematological and biochemical profiles of these fish across two sampling sites (Jhelum Bridge Khushab, upstream, and Langarwala Pull—downstream) were also evaluated. Results showed greater bioaccumulation of heavy metals in fish downstream, correlating with higher concentrations of these metals in water and sediments downstream. In the case of B. marinus, the highest concentration observed was 16.59 mg/g (Ca), and the lowest concentration was 9.51 mg/g (Fe). In the case of B. bagarius, the highest concentration observed was 17.47 mg/g (Ca), and the lowest concentration was 7.95 mg/g (Mg). Increased activities of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were observed downstream. Hematological changes included increased white blood cells (WBCs) and decreased red blood cells (RBCs), lymphocytes, hemoglobin (Hb), platelets (Plt), and hematocrit (Hct). A significant correlation was observed among heavy metals across the water, sediment, and different tissues of B. marinus and B. bagarius. Moreover, principal component analysis (PCA) for both species along both sampling sites illustrated the relationship between fish tissues and metals. The current study concluded that the fish accumulated a significantly higher concentration of heavy metals downstream, which might be linked with dumping of the domestic wastes and industrial and agricultural runoff, adversely affecting both fish and human health.