CONTENTS OF TRACE-METALS IN FISH, SEDIMENT AND WATER FROM 3 FRESH-WATER RESERVOIRS ON THE INDUS RIVER, PAKISTAN

Concentrations of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Hg are reported in 11 common fish species, along with relevant sediment and water, from three freshwater reservoirs and the outfall area of the Indus River, Pakistan. Rita rita, Wallago attu and Cirrhinus mrigala common to the three reservoirs, and Channa marulius, Mystus vittatu, Catla catla, Labeo calbasu, Mustacembelus panacalus, Notopterus notopterus and Mystus seenghala from the outfall area are included in the study. The criterion of weight dependence of trace metals is examined on the basis of the baseline metal data for the species from the three freshwater reservoirs. Metal concentrations in Rita rita from the Tarbela reservoir ranged from 0.082 to 6.715-mu-g g-1, wet weight, for Cd and Fe, and were higher than those in Wallago attu and Cirrhinus mrigala. Rita rita from the Lloyd reservoir showed a range of trace metals from 0.120-mu-g g-1 to 2.850-mu-g g-1, for Cr and Fe respectively. In the remaining fish, As ranged from 0.005 to 0.110-mu-g g-1, Cr from 0.065 to 0.44-mu-g g-1, Cu from 0.002 to 0.180-mu-g g-1, Fe from 0.725 to 3.445-mu-g g-1 and Hg from 0.240 to 4.785-mu-g g-1. The present study showed no correlation between the trace metal contents in water, sediment and fish. The findings are examined in terms of the probable pollution of the Indus River by industrial and municipal wastes.