KARACHI: A recent study conducted by Karachi University (KU) has showed that the Port Qasim coastal area is highly polluted, posing serious threat to the area’s biodiversity.

Titled Monitoring of anthropogenic impact on the Port Qasim coastal area, Karachi, Pakistan, the study was carried out by Prof Moazzam Ali Khan and Dr Aamir Alamgir of KU’s Institute of Environmental Studies.

Under the study, samples of seawater were collected from 23 locations, including Bundal Island, and were analysed for physico-chemical characteristics to determine the extent of pollution.

Samples were also analysed for heavy metals, such as arsenic, chromium, copper, cadmium, lead and nickel.

The investigation has revealed that the Port Qasim coastal area is grossly polluted with inorganic and organic contaminants mainly due to waste water effluent being discharged into the sea from various industrial set-ups.

Extensively high organic load has been found at the site receiving waste water from Landhi’s Cattle Colony.

According to the study, seawater samples showed high oil and chemical contents. Out of all heavy metals, the concentration of chromium and lead has been found exceptionally higher. The distribution of heavy metals demonstrated a typical diffusion pattern from the land to the direction of the sea.

Pollution source

On the area’s geography and the kind of activities being carried out in its jurisdiction, the study says that the deep-water seaport is spread over 12,000 acres. Gharo, Kadiro and Phiiti creeks constitute the approach channel to Port Qasim.

“These creeks are linked with mangrove patches and mudflat ecosystems. The system of these creeks is approximately 28km long and its width ranges from 250m to 2.5km. Within Port Qasim’s jurisdiction, many industrial zones are operating, including automotive industry. Two other major industrial set-ups are Pakistan Steel Mills (PSM) and an electricity generation plant.”

The mangroves in the area, it says, are constantly under threat owing to indiscriminate discharge of both domestic and industrial effluent.

The study also found seawater temperature very high (60-65 centigrade) at one point receiving discharge from a thermal power plant which, according to the study, had destroyed marine biodiversity at that particular location.

Two sample sites receiving untreated industrial effluent from Landhi industrial estate exhibited extremely high pollution load both in terms of organic and inorganic forms.

The sampling stations closed to Bundal Island are relatively less polluted. This could be mainly due to the dilution factor.

In general, the concentration of chemical oxygen demand (the amount of oxygen required to degenerate all pollution in a chemical way) and total concentration of organic nitrogen and ammonia, oil and grease, all pollutants considered very detrimental to marine biodiversity, was found exceptionally higher in most samples.

“Although, dissolved oxygen concentration was low, it may prevent anoxic condition. From the ecological viewpoint the concentration of phenol and cyanide was much higher although no significant point source of these pollutants was identified.

“Nutrient parameters were relatively higher in concentration in samples collected from the mangrove area. Concentration of nickel and chromium was also high, indicating industrial discharges from tanneries. Presence of high lead concentration indicates use of lead-based fuel likely being used by fishing motor boats,” it says.

Published in Dawn, November 21st, 2018