Eutrophication was recognized ...

Eutrophication was recognized as a water pollution problem in European and North American lakes and reservoirs in the mid-20th century. Since then, it has become more widespread. Surveys showed that 54% of lakes in Asia are eutrophic; in Europe, 53%; in North America, 48%; in South America, 41%; and in Africa, 28%. Eutrophication is a process by which plant growth increases in a lake or pond. In time, eutrophication may cause plants to completely fill in the area where a lake or pond once stood. The accelerated growth and overcrowding of plants is due to either natural fertilizing agents that are washed from the soil, or the runoff of chemical fertilizers applied to agricultural lands. Eutrophication may also be brought about by the drainage of sewage, industrial wastes, or detergents into a body of water. Eutrophication can be human-caused or natural. Untreated sewage effluent and agricultural run-off carrying fertilizers are examples of human-caused eutrophication. However, it also occurs naturally in situations where nutrients accumulate , or where they flow into systems on an ephemeral basis. Eutrophication generally promotes excessive plant growth and decay, favouring simple algae and plankton over other more complicated plants, and causes a severe reduction in water quality. At the same time the aquatic life is in danger as the high algae production on the surface of water disallow the sunlight to penetrate inside the water. One of the best remedies for eutrophication is to divert the nitrogen and phosphorus to a different path. Planting a buffer zone of trees and shrubs around a water body removes the fertilizer before it reaches the water.