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Non-points sources: a significant source of contamination

Though much of the initial attention in dealing with ocean and coastal environmental problems went to specific sources over the past three decades – oil from tankers, radioactivity from atom bomb tests and nuclear power plants, or sewage from municipal and hotel pipes – the focus of marine scientists recently has also embraced diffuse sources of contamination. Ocean impacts from agriculture, forestry and development as well as nutrients and particulate matter carried to the sea by rivers and atmospheric deposition of metals and chemical compounds have made clear the linkages between human and ecosystem health on land, in the air and at sea.

Non-point sources such as septic fields, and pit or overwater latrines, continue to cause significant contamination. There are some simple answers here: pits and latrines can be converted to septic tanks, existing tanks can be better designed and maintained, and better provision for disposal can improve the situation. But many systems fail because pits are not emptied or maintained.

As for other sources, providing storage for motor oil wastes can hold back a considerable pollutant, creation of wetlands can help cut nutrient flows, and changes in agricultural practice can reduce run-off. All will make a bigger impact through public awareness campaigns. Other capital and technological investments ijn developing countries may need support from international donors.