Written By: M. Zubair
Pollution is a concept that broadly indicates when a resource has become unsuitable for a particular purpose. Early indicators of global dispersion of harmful substances through the atmosphere and into the marine environment were noted with the reproductive failure of marine birds along the California coast. This was the first biological evidence of the worldwide dispersion of contaminants.
Pakistan has a coastline of 1001 km, extending from Sir Creek in the east to Gwadar in the west. Most of this coast is sparsely populated and thus less polluted. However, marine pollution is concentrated around Karachi and its adjoining areas due to the city’s large population and industrial presence. Karachi’s coastline, particularly Karachi Harbour, faces serious threats from industrial and municipal pollution, which is visibly evident. The polluted waters of the Manora Channel also affect major vessels and the infrastructure of Karachi Port.
A United Nations report found that the Indus River has the second highest amount of plastic waste dumped into it, at 164,332 tonnes. Additionally, 580 million gallons of untreated waste are dumped into the Arabian Sea from Karachi daily. Most of this waste is industrial, originating from Lahore, Faisalabad, and Sialkot, which ends up in rivers, lakes, and seas. The World Wildlife Fund (WWF) noted that plastic constitutes 50 per cent of beach pollution, with marine life previously threatened by overfishing now facing a significant threat from plastic waste.
Marine pollution, due to its dangerous and devastating effects, is considered a major threat to all stakeholders and the environment. Karachi, a hub of activities, generates approximately 500 million gallons per day (MGD) of wastewater and chemicals, which are discharged into the sea through various means. This untreated municipal and industrial wastewater, containing toxic waste and a variety of pollutants, severely impacts marine life, berthed vessels, and harbour infrastructure, including Pakistan Navy warships and Karachi Port Trust assets. Polluted water has become a significant challenge for the smooth operation of machinery on board ships in the harbour, leading to higher maintenance costs and efforts to replace corroded and deteriorated parts.
Major sources of marine pollution and its impact
The seas have suffered from human activities for many eras, as far back as Roman times. However, studies reveal that the destruction of coastal areas has accelerated rapidly in the past three centuries due to industrial discharge and runoff from farms and coastal cities. The oceans were once believed to be vast enough to dilute any pollution dumped into them. Until the mid-twentieth century, many scientists supported the notion that the oceans could harmlessly absorb pollutants. Advocates of this view had a slogan: “The solution to pollution is dilution.”
According to former Director General of the Marine Fisheries Department, Mr. Moazzam Khan, approximately 500 MGD of waste is produced in Pakistan, with 472 MGD being discharged into the sea through the Lyari and Malir Rivers and eight major streams (nullahs). Of this, about 327 MGD is discharged through the Lyari River, 108 MGD through the Malir River, and the rest through various nullahs. This sewage includes domestic waste from Karachi, a metropolis with a population exceeding 25 million. Over 6,000 registered industrial units in Karachi, located in industrial estates such as SITE, Landhi, Korangi, Malir, and the Port Qasim Authority area, lack proper disposal systems for liquid and solid waste, which ultimately ends up in the marine environment.
A portion of the garbage generated in Karachi is unaccounted for and not properly disposed of by civic authorities. Data indicates that about 13,000 metric tonnes of garbage is generated daily in Karachi, with approximately 8,000 tonnes taken to dumpsites at Deh Jam Chakro and Gond Pass, leaving about 5,000 tonnes to become part of the environment. Despite improvements, a significant amount of solid waste, including plastic, is not properly removed.
Types of marine pollution
The United Nations defines marine pollution as the introduction by humans, directly or indirectly, of substances or energy into the marine environment, resulting in harmful effects such as hazards to human health, hindrance to marine activities, impairment of seawater quality, and reduction of amenities. Marine pollution occurs when toxic or potentially toxic substances, chemicals, agricultural, industrial, and household waste enter the sea. Major causes of marine pollution include solid waste influx, chemical discharge, radioactive elements, industrial and agricultural runoff, oil spills, and sedimentation. Additionally, air pollution contributes by depositing wind-blown debris, dirt, dust particles, and pesticides into seawater. Both forms of pollution are harmful to aquatic ecology and terrestrial life. Ship pollution and deep-sea mining also significantly contribute to marine pollution.
Marine pollution in Karachi port
Karachi is Pakistan’s most populous city and a major port in South Asia, handling about 60pc of the country’s cargo, approximately 25 million tonnes annually. Managed by Karachi Port Trust (KPT), the port has a natural deep harbour channel facilitating safe navigation for large vessels. However, industrial effluents and other pollutants dumped into the harbour severely impact the marine ecosystem and port infrastructure. Polluted water from various sources, including domestic waste, paint, oil spills, and industrial effluents, leads to corrosion of ships and machinery, increasing maintenance costs.
Marine pollution and its impact on marine ecosystems
Dr. Quddusi B. Kazmi, former Director of the Marine Reference Collection and Resource Centre at the University of Karachi, emphasised the complex interaction between natural and anthropogenic sources of marine pollution, particularly nitrogen, phosphorus, medicament, and plastics. Despite the global significance of marine pollution, systematic observations remain limited. Effective action against marine pollution requires a more resourced and systematic approach. Strict adherence to international maritime laws is essential to protect marine environments.
Karachi faces serious marine pollution issues due to inadequate sewage treatment and solid waste disposal. Of the 500 MGD sewage generated, only 55 MGD is treated, with the remaining 445 MGD dumped untreated into the sea, severely impacting marine biodiversity. Effective waste management is crucial for reducing marine pollution.
Former Director General Moazzam Khan noted the lack of innovative technologies for controlling marine pollution in Pakistan. Traditional sewage treatment and solid waste disposal practices are inadequate. Public awareness is crucial for reducing marine pollution. Efforts should include regular awareness programmes targeting school children, housewives, youth, and the general public to combat marine pollution effectively.
Disclaimer: The views expressed in the article are writer’s own and do not reflect the opinions and views of The Upcut.