Study shows Karachi coastline faces severe pollution

The Karachi coastline, which is more than 135 km-long, is facing severe pollution due to a combination of factors resulting from industrial, port, municipal, and transportation activities in the area, a survey shows. A study found that some of the marine life was contaminated with lead, which if consumed by humans through seafood, has been linked to anaemia, kidney failure and brain damage.
The study also revealed that even the mangrove forests - protecting the feeder creeks from sea erosion as well as a source of sustenance for fishermen - are threatened by this pollution. Pakistan is heavily dependent on these mangrove forests to maintain ecological balance. The mangrove leaf litter provides a major source of nutrients.
The mangroves provide a diverse habitat for a complex and interdependent community of invertebrates, fish, birds, and reptiles; and the primary productivity of these mangrove-covered dialytic areas is four to seven times those of coastal areas without mangroves. The shipping industry, through its discharges, water pollution, and possible leakages and spills, impacts on this environment.

The greatest pollution occurs at Karachi Port -- because of its high usage -- from vessels illegally pumping out bilges and refuse at the port's oil terminal. Sewage and garbage from visiting vessels are often uncontrolled, and though the offenders are often fined by port authorities, this has not proved an effective deterrent. Moreover, port authorities are ill-equipped and inadequately trained to recognize other hidden toxic dumping activities, such as dumping toxic waste at sea or by leaving wrongly labelled containers on land.
The World Bank noted in an environmental study that "sewage and toxic matter (pollution at the Karachi Port) includes:
(i) toxic effects either direct or indirect by bio-accumulation of oil, DDT, PCB, and various metals;
(ii) avoidance reaction by fish and shrimp because of poor water quality;
(iii) distortion of organisms and reduction in their reproduction because of poor water quality and the fact that parts of the mudflat areas are being covered with oil; and
(iv) increased erosion because dying mangroves can no longer reinforce the banks with their roots."

The port is also affecting the environment with its heavy shipping of oil and subsequent dredging activities: traits common in the shipping industry. Due to the country's spiralling dependence on oil imports, oil is one of the major cargoes imported at the port. However, an estimated 90,000 tpy of oily discharges are pumped out within port limits and there exists no oily ship waste reception or treatment facility within the port.
In addition, a common environmental problem associated with the shipping industry, dredging, is having a major impact. Dredging is the process of removing silt build-up in the port from entering and exiting of ships. The dredged material is dumped out to sea to maintain the port. However, there is no system for monitoring trace metal in the dredged spoil which is further deteriorating the environment.
A significant percentage of coastal pollution is contributed when the export industries ship their goods through the Karachi Port. The port induces polluting industries to set up shops nearby in order to expedite exportation. The pollution from these industries is affecting the environment because much of the factories' effluents are untreated and released directly into the port area.