Bioaccumulation of heavy metals and their effect on vital organs of labeo rohita in ponds and natural water bodies

Abstract

Labeo rohita was sampled to determine the contamination levels of chromium, lead, nickel, copper and manganese from wild (Trimmu and Balloki Headworks) and controlled fish ponds at Ravi Campus (UVAS) from September to December, 2013. Sampled fish were blotted dry, weighed and liver and intestine were removed to study histology and metals concentration. Chromium seems ubiquitous and was detected in all the water samples as well as liver and intestinal tissues of experimental fish. Its level was lowest in water samples and fish organs in samples collected from UVAS fish ponds while the highest in samples collected from Balloki Headworks, the main recipients of waste from Lahore city. Fish liver depicted Chromium (Cr) only but the intestine revealed the presence of Nickel (Ni), Lead (Pb), Manganese (Mn) and copper (Cu) too. Cadmium was below the detectable limit in all water and tissues (liver, intestine) of sampled fish. Heavy metals load and their range induced pathological alterations, infiltration and necrosis in liver and intestinal tissues. Canonical discriminate analysis of Cr, Cu, Mn, Ni, Pb and Cd and the extent of histopathological changes differed significantly among localities establishing an appropriate link with living media and their vertical flow in fish.