News
Monday, May 23, 2011
Chemical inflows poisoning Karachi coastal waters
* Impacts of pollutants on commercial finfish and shrimp fisheries unknown, but likely to be significant
KARACHI: Karachi is the largest city of Pakistan and a hub of industrial activity. However, its coastal zone is extended up to 135 kilometres that is exposed to heavy pollution load of both domestic and industrial origin, says a report of the Society for Human Rights & Environment Protection (SHEP) on chemical water pollution.
The report says discharges of sewage and industrial effluent into aquatic and marine ecosystem are also on the rise. The organic load of sewage depletes oxygen levels in water and indirectly reduces the diversity of animals and plants life.
Most of the coastal pollution is concentrated in Karachi harbour where an estimated 90,000 tonnes of oil products from vessels and port terminals are dumped every year. Extremely high levels of toxic heavy metals such as mercury have been documented, especially in the coastal waters and sea near Karachi. These are likely to have both acute and chronic toxic impacts on human beings, marine biodiversity and fish-eating birds.
The impacts of these pollutants on commercial finfish and shrimp fisheries are unknown, but are likely to be significant, the report says.
Rehri creek is one of the neighbourhoods of Bin Qasim Port and support a large community of fisherman. It stretches to 21.7 kilometres in the south east of Karachi coast. Its microenvironment comprises of the coastal area of Bin Qasim district, which includes the union council of Rehri Goth and Ibrahim Hydri besides the two settlements of Chashma Goth and Laath Basti.
Rehri creek is the heavily polluted area of Karachi coast, where the effluents from Korangi, Landhi, Karachi Export Processing Zone, Bin Qasim Industrial Area and Pakistan Steel Mills are directly discharged into the sea. In addition to these, untreated waste water from metropolis of
Karachi and domestic effluents from smaller coastal settlements is also released into the coastal water. The consequent contamination of fisheries and other fauna poses serious and potential health hazards.
The creeks area is dominated by mangroves that serve as a spawning and nursery ground for a number of commercially important marine fauna.
The toxic pollutants from the Rehri creek area reach to the mangrove areas. In addition, pollution from domestic, industrial effluents and Cattle Colony waste causes eutrophication and increases biomass in the form of algal bloom, which affects not only economically important marine fauna, but also affects mangrove seedlings.
These algal blooms grow profusely and inhibit the growth of mangrove seedlings that results in mortality of mangroves on a large scale.
Serious steps on behalf of all the stakeholders are required to end the pollution of coastal areas of Karachi. ppi
Courtesy www.dailytimes.com.pk