KARACHI, Feb 17: There is a need for an effective legislation to make it mandatory upon industries to treat their effluents before discharging them into the sea, say fishery sources.

These sources blame untreated industrial effluents and floating garbage as one of the key factors for pollution in the Karachi Fish Harbour, saying that unless the sources of pollution are plugged, there would be no improvement in the situation.

The Karachi Fish Harbour plays a key role in fish trade and is contributing significantly to foreign exchange earnings. But ironically, it is facing a serious pollution problem mainly because of untreated municipal and industrial pollutants.

These sources while suggesting setting up of sewage treatment plants at the source say, although the sea is supposed to be the best sewage scheme, it too has its own capacity, as it is not meant for treating persistent man-made chemicals.

At the same time, these sources also suggest that a strong legislation be enforced to make it mandatory upon the industries to treat their effluents before discharging them into sewers.

According to the sources, the pollutants generated by these industries include gross organic, bacteria liquids, acids toxin metals, oil and oily wastes, salts, fibres, and plastics etc.

The Lyari River, which channels the city's untreated sewage and industrial effluents from the SITE area, drains directly into the Arabian Sea through the western backwards of the Karachi Fish Harbour.

Apart from municipal sewage, the Lyari River also brings in a heavy load of floating garbage. But, worst of it is the untreated discharge of hundreds of industries connected to Lyari in one way or the other. The sources said that these land-based pollutants, brought in by the Lyari River account for 50 per cent of the total pollution in the harbour.