The environmental impact of shipping activities include environmental impact on the coastal zones resulting from the development and operation of large-scale port facilities, and dredging and disposal of contaminated sediments for navigational purposes
Ships can affect the marine environment through oily discharges, tank cleaning, or if they have an accident and lose their cargo, although the scale of any impact generally depends on the location and the type and amount of substances released. There is also the effect of marine organisms that ships can carry from one bio-geographical area to another within their ballast water or attached to their hulls. This article is a summary of various pollutants to the sea from ship activities. It provides a brief of those pollutants and some of their environmental and health impacts.
Exhaust emissions from ships are considered to be a significant source of air pollution, with 18 to 30 percent of all nitrogen oxide and 9 percent of sulfur oxide pollution. Sulfur in the air creates acid rain which damages crops and buildings. When inhaled the sulfur is known to cause respiratory problems and even increase the risk of a heart attack.
As estimated by the International Maritime Organization (IMO), Carbon dioxide emissions from shipping is estimated to be 4 to 5 percent of the global total, and will rise by as much as 72 percent by 2020 if no action is taken.
3.5 to 4 percent of all climate change emissions are caused by shipping. Air pollution from cruise ships is generated by diesel engines that burn high sulfur content fuel oil, also known as bunker oil, producing sulfur dioxide, nitrogen oxide and particulate, in addition to carbon monoxide, carbon dioxide, and hydrocarbons. Diesel exhaust has been classified by USA EPA as a likely human carcinogen. USA EPA recognizes that these emissions from marine diesel engines contribute to ozone and carbon monoxide non-attainment (i.e., failure to meet air quality standards), as well as adverse health effects associated with ambient concentrations of particulate matter and visibility, haze, acid deposition, and eutrophication and nitrification of water. Ultra-low sulfur diesel (ULSD) is a standard for defining diesel fuel with substantially lowered sulfur con-tents. As of 2006, almost all of the petroleum based diesel fuel available in Europe and North America is of a ULSD type, as one way to reduce the impact of greenhouse gas emissions from shipping is using higher rated ships that deliver significantly lower CO2 emissions across the voyage length.
Solid waste generated on a ship includes glass, paper, cardboard, aluminum and steel cans, and plastic. It can be either non-hazardous or hazardous in nature. Solid waste that enters the ocean may become marine debris, and can then pose a threat to marine organisms, humans, coastal communities, and industries that utilize marine waters. Cruise ships typically manage solid waste by a combination of source reduction, waste minimization, and recycling. However, as much as 75 percent of solid waste is incinerated on board, and the ash typically is discharged at sea, although some is landed ashore for disposal or recycling. Most cruise ship garbage is treated on board (incinerated, pulped, or ground up) for discharge overboard. When garbage must be off-loaded (for ex-ample, because glass and aluminium cannot be incinerated), cruise ships can put a strain on port reception facilities, which are rarely adequate to the task of serving a large passenger vessel.
Greywater is waste water from the sinks, showers, galleys, laundry, and cleaning activities aboard a ship. It can contain a variety of pollutant substances, including fecal coli forms, detergents, oil and grease, metals, organic compounds, petroleum hydro-carbons, nutrients, food waste, medical and dental waste. Sampling done by the USA EPA and the State of Alaska found that untreated grey water from ships can contain pollutants at variable strengths and that it can contain levels of fecal coliform bacteria several times greater than is typically found in untreated domestic waste water. Grey water has potential to cause adverse environmental effects because of concentrations of nutrients and other oxygen-demanding materials, in particular. Grey water is typically the largest source of liquid waste generated by ships (90 to 95 percent of the total). Estimates of grey water range from 110 to 320 liters per day per person, or 330,000 to 960,000 liters per day for a 3,000-person cruise ship.
Noise pollution caused by shipping and other human enterprises has in-creased in recent history.The noise produced by ships can travel long distances, and marine species who may rely on sound for their orientation, communication, and feeding, can be harmed by this sound pollution . The Convention on the Conservation of Migratory Species has identified ocean noise as a potential threat to marine life.
Marine mammals, such a whales and manatees, risk being struck by ships, causing injury and death. For example, if a ship is traveling at a speed of only 15 knots, there is a 79 percent chance of a collision being lethal to a whale.
One notable example of the impact of ship collisions is the endangered North Atlantic right whale, of which 400 or less remain. The greatest danger to the North Atlantic right whale is injury sustained from ship strikes. Between 1970 and 1999, 35.5 percent of recorded deaths were attributed to collisions. During 1999 to 2003, incidents of mortality and serious in-jury attributed to ship strikes averaged one per year. In 2004 to 2006, that number increased to 2.6. Deaths from collisions has become an extinction threat.
Blackwater is sewage, waste water from toilets and medical facilities, which can contain harmful bacteria, pathogens, viruses, intestinal para-sites, and harmful nutrients. Discharges of untreated or inadequately treat-ed sewage can cause bacterial and viral contamination of and shellfish beds, producing risks to public health. Nutrients in sewage, such as nitrogen and phosphorus, promote excessive algal blooms, which consumes oxygen in the water and can lead to fish kills and destruction of other aquatic life.
Some of the major international ef-forts in the form of treaties are the Marine Pollution Treaty, Honolulu, which deals with regulating marine pollution from ships, and the UN Convention on Law of the Sea, which deals with ma-rine species and pollution. While plenty of local and international regulations have been introduced through-out maritime history, much of the current regulations are considered in-adequate. “In general, the treaties tend to emphasize the technical features of safety and pollution control measures without going to the root causes of sub-standard shipping, the absence of incentives for compliance and the lack of enforceability of measures.”
All countries that possess navies, coast guards, and other governmental bodies that have vessels under their charge should be compliant with all regulations pertaining to the water-ways and environment. Many countries have implemented requirements of Class standards to ensure the impact of military and governmental vessels from these organizations during normal peace time operations minimize that negative impact.
by Dr. Aseel Takshe Abdul Wahab Environment, Health & Safety (EHS) Manager, Tasneef