Many other industries use chemicals that can be dangerous water pollutants. Not only can chemicals from photographic processors, laundries and dry cleaners, paint factories, metal working or plating companies, etc. be poisonous or harmful in themselves, but if they get into septic tanks, waste treatment plants, streams or lagoons they can also slow or stop the microbes that would otherwise break down and purify organic wastes, making other water pollution problems worse. Oil pollution . Unfortunately we cannot seem to help spilling some of it while we use it, and it can thus get into the water. Since oil products arrive in the islands by ship, the risks of oil spills are greatest in the vulnerable lagoons, harbours and coastal waters, either in accidents while unloading the oil, in spills from storage tanks or facilities, or more rarely in the grounding of ships carrying oil.
Oil can smother animals, mangrove roots, and other seashore life.
If waves break the oil up into small globs, it may be eaten by fish and shellfish, giving them an oily taste. Since oil breaks down very slowly, it can take a long time for oil pollution to go away. Agricultural runoff . Modern agriculture frequently requires chemicals such as fertilizers and pesticides. Unfortunately these do not always stay in the fields where they are needed, but may wash off with the rain into streams or the lagoon.