Assessment of Marine Coastal Water Pollution from Karachi Harbour Pakistan

Abstract

: In Pakistan, marine pollution is a major problem that is caused by the waste from industrial, municipal,agronomy, and oil leak sources. The pollutant loads along with the coastline areas near Karachi is received fromterrestrial contaminants including discharges from Karachi Harbour located on the estuary of the Lyari river. Karachigenerates 472 Million Gallon per Day (MGD) of wastewater out of which only 55 MGD is treated and the rest isdischarged in the sea. The prevailing sewage treatment plants are functioning at reduced capacity due to the insufficienttransmission capacity of interceptors. Water sampling was carried out from the Lyari River and five different selectedcoastal point around Karachi harbour for physicochemical parameters and selected heavy metals. Results show that theKarachi Harbour area is noticeably polluted, whereas; the coastal environment in the vicinity of Karachi is also underthe stress of pollution. High COD and BOD5 values were noticed at the Lyari river samples and the sampling locationsclose to the Lyari river outfall area. The Pb, Cd, Ni, and Hg heavy metals that pollute marine water are found. Thissituation is due to the discharge of mixed effluents of industrial and domestic wastes as well as dredging, cargohandling, dumping of ship waste and other coastal activities. The highest value of pollution observed at KarachiHarbour which is near Lyari river mouth, where the domestic and industrial effluents with organic and inorganic wasteshave a greater influence on the water quality and the marine environment. At present, there is no effective controllingmechanism for industries to treat their waste, nor has any investigation to assess increasing marine pollution beencarried out. As a result, there is an adverse impact on fish habitat and mangroves, corrosion of cargo ships, navalvessels and the residents living in the coastal area. Therefore, the government agencies and industrial sectors shouldwork together to avert marine pollution and attain total environmental sustainability.