SELECTED TRACE-METALS IN FISH, SEDIMENT AND WATER FROM FRESH-WATER TARBELA RESERVOIR, PAKISTAN

Selected trace metals and macronutrients in the edible muscle of thirt een freshwater species, harvested from Tarbela Reservoir on the Indus River, Pakistan, along with relevant sediment and water are reported. The fish selected were: Catla catla, Channa marulius, Cirrhanus mrigal a, Cyprinus carpio, Labeo calbasu, Labeo rohita, Mastacembelus aramatu s, Mystus seenghala, Mystus vitatus, Notoptirus chitala, Rita rita, To r putitora and Wallago attu. Labeo calbesu showed maximum levels of si lver and arsenic at 1.179 and 0.713 mug/g, respectively, where as, Not optirus chitala showed maximum concentrations of cadmium (1.013 mug/g) . Mercury was at 2.870 mug/g in Channa marulius and lead at a concentr ation of 2.108 mug/g in Mastacembelus aramatus. A reciprocal relations hip was observed between the macronutrient content and trace metal con centrations in species like Rita rita and Wallago attu. Sediment showe d maximum concentrations of iron and manganese, whereas, arsenic and l ead concentrations were observed at higher levels in water. The study showed decreasing order of concentrations of trace metals and macronut rients as: sediment > fish > water.