The state of pollution levels of Karachi harbour and adjoining coastal water

A study was carried out recently to determine the pollution level of waters in the Karachi harbour and adjoining backwaters. Nine locations were selected, four in the backwaters, two on the seaside, and three in the main navigable channel. Four of these locations were deliberately selected to coincide with those of a previous study conducted in 1982 by Pakistan Council of Scientific and Industrial Research (PCSIR) so that the values for the concentration of different pollutants could be compared. Analysis was conducted for pH, bicarbonates, Total Solids, Volatile matter in Total Solids, Chlorides, Sulphates, Calcium, Magnesium, Sodium and Potassium. The results indicate that the composition of sea water as far as the concentration of above constituents is concerned has not changed much since the time of the PCSIR study, viz 1982, except that the organic matter concentration has increased. The reasons for this increase in organic loading and its possible impact are discussed in this paper.