Water quality, pollution from shipping Coastal areas are densely populated because of their highly valued ecological richness and support of human activities. These activities however put pressure on these valuable ecosystems. Industries like power plants, fisheries, mining, shipping and recreation contaminate the coastal waters. But also natural events like storms, erosion, and discharge of sediments have a significant effect on the water quality. Each of these natural and human stresses can deteriorate the water quality in more than one way. Shipping, for example, greatly impacts coastal water quality through ballast water discharge, exhaust emissions, oil spills, solid waste, and sewage such as black water, grey water and bilge water. Exhaust emissions Diesel engines burn high sulphur content fuel oil, also known as bunker oil, producing sulphur oxide, nitrogen oxide, atmospheric particulate matter, carbon monoxide, carbon dioxide and hydrocarbons. The US Environmental Protection Agency (EPA) classifies diesel exhaust to be a human carcinogen and recognizes marine diesel exhaust to significantly contribute to acid deposition, eutrophication and nitrification of water. Oil spills In addition to oil spilling from daily operations, large oil spills have a devastating effect on the coastal waters. When oil is spilled at sea, it breaks down into various chemical and physical components. These can be coating organisms and coastal habitats, floating or suspended in the water, sunk to the bottom, and buried in sediments. |