Sources of Pollution

Direct discharge from point-sources to coastal areas consist of the following activities:

Sources of Pollution in the Marine Environment
Land-Based Sources
Point Sources
Non-Point Sources
Ocean Sources
Atmospheric Sources

  • Urban development in coastal areas is intense in most parts of the world. Many large cities are located close to the coast and most of them are ports and centers for trade, services and industries. Often coastal cities are also capitals of government, providing the administrative and political center of a country. The concentration and high growth rate of the population in large urban areas on the coast results in significant impact on and interaction with the coastal and marine environment.

  • Runoff from urban areas and infrastructure brings a wide range of pollutants to coastal areas via rainwater and drainage systems, including leakage from waste disposal sites and airborne pollutants in dust from traffic, combustion and other activities. Pollutants from land also reach coastal waters via a number of pathways. Non-point sources include surface run-off of nutrients, inorganic and organic residues from agricultural and urban areas and sediment transport to the sea from erosive land-use. To reduce pollution from non-point sources major changes in complex land-use patterns are required.

    In urban areas waste streams are often mixed in with sewage systems. The effects of the discharge of pollutants on the coastal environment depends on the load and treatment of waste water, the discharge system and the physical/biological characteristics of the receiving water body. The most widespread effects of urban and industrial discharges are:

    • health risks from the presence of sewage pathogens
    • eutrophication/oxygen depletion due to nutrients and organic carbon
    • toxic effects on marine organisms and human health risks caused by chemicals in seafood

    The lack of proper land use planning, including effective zoning and environmental review procedures in the coastal zone - particularly with regard to urban development, industrial expansion and investment for domestic and foreign tourism expansion - is a growing problem in many parts of the Region. Development often proceeds without benefit of adequate planning or evaluation of potential environmental impacts. In some cases local authorities allow construction activities which are inconsistent with land use patterns or plans and which do not make adequate provision for the collection and treatment of liquid and solid wastes. Poorly controlled development has especially been a problem associated with medium- and small-scale industries outside planned industrial areas and for a wide range of tourism developments in the northern section of the Red Sea. If steps are not taken to conserve and protect the unique environments of the Region through planning activities within a framework for ICM, the high costs of remediation and possibly irreversible impacts from development could quickly undermine the ecological integrity of the coastal environment and prospects for further economic growth.

    In connection with urban development, the discharge of municipal wastewater continues to present considerable management problems, despite the significant progress made over the last decade through investments to control pollution from this source. In the Region, especially on the west coast of the Red Sea south of Suez, the discharge of domestic sewage contributes, through nutrient loading and high biological oxygen demand (BOD), to the eutrophication of coastal waters around selected population centers, major ports and tourist facilities. Considerable progress has been made in the Region in the collection and treatment of municipal wastewater; however, investments continue to be required for extension of collection networks, expansion and upgrading of treatment facilities, and development of safe wastewater reuse and disposal systems. Serious efforts are also needed to ensure proper operation and maintenance and reliable performance of existing treatment facilities. While levels of discharge into the waters of the Region are not as acute as in other regional seas given the limited number of major population centers, results are cumulative and add to the stress already imposed on fragile coastal habitats by oil and other forms of marine pollution.

  • Industrial activities contribute significantly to the load of a wide range of complex pollutants in coastal waters. Factors contributing to the high load of pollutants entering the marine environment are the environmentally poor siting of industries; old and environmentally unsound internal processes, lack of maintenance, poor supervision of production processes, and lack of regulation and enforcement. Industrial effluents are often mixed with urban wastewater where they significantly contribute to the environmental impact of large urban growth.

  • Dredging and Filling

    Dredging and filling operations associated with urban expansion, industrial development and tourism along the coast are a significant source of environmental degradation in the Region. Sedimentation from these operations suffocates the surrounding coral reef communities and has an adverse effect on other ecosystems to which currents transport suspended sediments. The net results can be the irreversible loss of the most productive coastal ecosystems - mangroves, seagrass beds, and coral reefs- and the potential for local extinction of endemic species, along with declines in the productivity of surrounding areas such as shrimping grounds and other demersal fisheries. Dredging and filling also alters shorelines, leading to erosion in some sites and accretion in others.

  • Atmospheric pollution

    Atmospheric pollution from industry, power plants, residential heating and traffic may be deposited directly in the coastal environment or brought to the sea by surface runoff. Locally airborne dust from industrial processes or port activities can de deposited in coastal areas and affecting sensitive environments such as coral reefs. As the main sources are located in the mid-latitudes of the Northern Hemisphere, the meteorological conditions favor transportation from west to east. Contaminants can travel hundreds to thousands of kilometers as gases or aerosol particles and are deposited into the ocean as gases or solids (dry deposition) or falling in rain and snow (wet deposition).

    Globally, the emission of greenhouse gases increases the temperature of the lower atmosphere. Resulting rise in sea surface temperature and sea level may have serious implications for coastal areas and marine productivity.

  • Tourism can also be considered an industry with pollution-related consequences. In fact, global tourism is the fastest-growing industry in the world and competition for markets is strong. The industry is an important earner of foreign exchange in the economies of several of the Region's countries. Coastal areas with their beautiful, scenic beaches and clean, clear water for swimming, diving, fishing and boating are attributes which help attract millions of visitors to coastal areas each year. Large scale tourism development can have several pollution-related impacts in the coastal zone (i.e. construction of tourism infrastructure in coastal areas, often directly on the shore, may contribute to increased loads of sewage and solid waste), and is covered in detail in Module #7.

  • Agricultural activities carried out in river valleys and flood-plains can contribute significantly to the pollution load of nutrients and agrochemicals to coastal waters. Agriculture extension, slash-and-burn practices and associated soil erosion also contribute to increased siltation and sedimentation.
    Inland and coastal forests are of critical importance for the health and productivity of the coastal environment. Upland deforestation in watersheds increases soil erosion and influences the flow of water and sediments to the sea. While deforestation is not an upland concern within the arid, coasts of the region, sedimentation from dust storms is an issue, and the clearing of coastal forests such as mangroves removes an important natural pollution trap and increase the release of sediments and contaminants to coastal waters.

    Sea-Based Sources of Pollution

    Pollution from ocean-based sources can be intentional (dumping); operational (ship ballast discharge); or accidental (oil and chemical spills). In contrast to other regional seas around the world where significant amounts of pollution come from land-based activities, a major source of marine pollution in the Region is from ship-based sources, oil exploration and offshore oil production. Over 100 million tons of oil are transported through the Red Sea annually, nearly half of which enters the Region via the Yanbu Petroline from the Gulf. This high volume of transport traffic results in chronic marine pollution from discharges of oily ballast water and tank washings by vessels, operational spills from vessels loading or unloading at port, accidental spills from foundered vessels, and leaks from vessels in transit.

    Shipping activities contribute a significant amount of pollution. The most important pollutant is oil, but noxious substances, garbage and sewage are also generated in maritime activities. Antifouling paint may also release some of the most toxic compounds ever introduced to the marine environment, such as organotin.

    Offshore petroleum exploitation, dredging and mining contribute significantly to operational and accidental pollution of oil, mineral sludge, turbidity and contaminated sediments. Considerable garbage and sewage often results from these operations. The Red Sea has extensive offshore non-petroleum mineral deposits that are of considerable long-term economic interest. Economically, it may be highly desirable from a regional and national perspective to develop these resources; however, measures should be developed and adopted to ensure that these activities do not cause significant or irreversible damage. Given the unique nature of the Red Sea and limited worldwide experience with the offshore recovery of manganese nodules and other forms of marine mineral wealth, measures should be taken to establish environmental guidelines for the development of these resources on a regional level.

    In a number of countries, industrial and municipal waste, mainly sewage sludge generated on land is disposed of by dumping at sea. Also other, more harmful material such as radioactive waste, military equipment and toxic waste is being dumped at sea. Some industrial wastes are so dangerous that their disposal is a major problem and incineration at sea by specially constructed ships may be the method used in a number of cases.

    Environmental and water quality degradation in port areas is often easily detected. In addition to Environmental impact from urban and industrial activities, port areas are subject to pollution loads from shipping, operational spills of cargo and fuel during loading and unloading of ships; accidental spills, dredging and construction, modification of coastline, intensive human activities environmental impact from urban and industrial activities, port areas are subject to pollution loads from shipping, operational spills of cargo and fuel during loading and unloading of ships; accidental spills, dredging and construction, modification of coastline, intensive human activities and accumulation of ship wrecks and other garbage.

    Fishing operations and aquaculture are important activities in the coastal zone. Both depend on a healthy coastal zone, but may also contribute to the degradation of water quality through the release of organic material, nutrients, and residues of organic substances.

    Marine Traffic, Oil production and Transport

    In the Red Sea and Gulf of Aden Region, exploration, production, processing and transportation of more than half the world's proven oil reserves take place. Most of the oil produced from both inland and offshore wells is exported, transforming the Red Sea into an oil tanker highway. Entering the Gulf each year are some 20,000-35,000 tankers which load their cargoes of oil for shipment to the far East and Europe. Many tankers proceed from the Gulf around the Arabian peninsula into the Red Sea, where they either continue north through the Suez Canal to the Mediterranean, or deposit their cargo at the entrance to the Sumed pipeline at Ain Sukhna in Egypt. Besides oil cargoes, many ships transit the Red Sea and Gulf of Aden fully or partly loaded with hazardous or toxic substances that pose an added threat to the coastal and marine environments.

    • Petroleum and Maritime Traffic

      The global importance of petroleum and the resulting maritime traffic pose a serious threat to the fragile coastal and marine environments of the semi-enclosed waters of the Region. Routine operational leaks and spills from the production and transport of oil constitute the major source of marine pollution. At the same time, the growing risk of oil traffic-related accidents urgently requires emergency response plans combined with management skills, to minimize risks and control major spills.

      In the Red Sea, insufficient and poorly maintained navigational aids, and unregulated maritime traffic in most parts, have created several high risk zones. These include the southern part of the Red Sea at Bab-al-Mandab and the Huneish Archipelago area, further north at the loading points for the Yanbu Petroline in Saudi Arabia and the Sumed pipeline at Ain Sukhna in Egypt, at the entrance to the Gulf of Suez and the Suez Canal, and through the Straits of Tiran at the entrance to the Gulf of Aqaba. There are other points in the Red Sea where south and northbound traffic converge to change course and where risks of collision are high and Traffic Separation Schemes should be established. Shipwrecks and cargo spills occurring in these high risk zones result in significant oil pollution and marine debris. Special risks are created in the Gulf of Suez by offshore platforms and well caps. In the southern Red Sea hazards are associated with the increasing numbers of commercial and fishing vessels, including many small local vessels. Additional risks to navigation in the Region include inaccurate navigation charts in some areas, and difficulties in radio communication. The potential for resumption of full-scale export of oil from the Gulf region and plans to increase the volume of oil transported via the Yanbu Petroline in Saudi Arabia and the Sumed pipeline in Egypt, along with the possibility of expanding the capacity of the Suez Canal to accommodate fully laden very large crude carriers (VLCCs) of up to 250,000 tons pose increased risks for major oil spills in the Region.

    • Other types of marine pollution

      Other forms of ship-generated waste include oily sludge, bilge water, garbage and marine debris. The risks of oil well blow-outs, spills and other production accidents associated with the offshore oil industry in the northern Red Sea constitute another significant threat to human and wildlife resources. Routine oil leaks, gas flaring, and dumping of oily sludge and muds containing hazardous materials from drilling operations are chronic sources of pollution. These risks will increase with the anticipated development of gas reserves and offshore oil resources in the southern Red Sea and Gulf of Aden. The marine and coastal environment of the Region is constantly threatened by the possibility of vessels foundering while carrying harmful materials other than oil. Though some measures have been taken and others are planned to deal with oil spills, preparedness to deal with chemical and other hazardous materials is almost non-existent.

    You are in Module 4: Sources of Pollution