Monitoring of anthropogenic impact on the Port Qasim coastal area, Karachi, Pakistan

Abstract

AbstractThe present study was undertaken to investigate the extent of pollution load at Port Qasim coastal area, the second largest port in the country. The samples of sea water were collected from 23 locations, including the samples from Bundal Island situated in the Port Qasim area. Samples were analyzed for physico-chemical characteristics to determine the extent of pollution load. Samples were also analyzed for heavy metals including As, Cr, Cu, Cd, Pb and Ni. The investigation revealed that the Port Qasim Area is grossly polluted from inorganic and organic loads mainly coming from the nearby industrial setup. Extensively high organic load was found at the site receiving the wastewater from the Landhi Cattle colony. PQ-6 receives untreated wastewater from oil industries as exhibited by its high oil content. PQ-14 is receiving untreated industrial discharges from the nearby chemical industries and represents a very high pollution load. The sites closed to Bundal Island are relatively less polluted. The mangroves in the area are constantly under threat owing to the indiscriminate discharge of both domestic and industrial effluents. The concentration of DO although not on higher side but at least prevents the anoxic condition in the area. Out of all the heavy metals the concentration of Cr and Pb was exceptionally higher. The distribution of heavy metals demonstrated a typical diffusion pattern from the land to the sea. Principal component analysis and cluster analysis of the data showed the major gradients, similarities of localities and the variables of importance in terms of overall variability in the pollution characteristics. It is concluded that the level of pollution is increasing at an alarming rate, which is detrimental to the biodiversity of the coastal area.