Eutrophication is one of the major forms of water pollution affecting lakes and reservoirs around the world today. It is due to the response in water to over-enrichment by nutrient point and non-point loadings from natural and "man-made" sources. This over-enrichment leads to the growth of rooted aquatic plants, algal mats, deoxygenation, and unpleasant asthetics. Nutrient sources from "man-made" sources include municipal, industrial wastewater, agricultural runoffs, and urban runoffs that contribute to eutrophication.
Algal blooms often clog filters of municipal and industrial water supplies necessitating frequent and costly cleaning procedures. The shores of formely clean lakes develop algal slimes, excessive algal turbidity or dense growth of certain rooted aquatic plants and filamentous algae in shallow areas. As a result, lakes become unattractive for bathing, boating, and other water-oriented recreations and result in severe economic loss to established resorts. The former users of such lakes must travel elsewhere at added expense. Fish production often increases but the species composition changes for the worst. Economically important species such as trout decline or dissappear and are often replaced by coarser fish, like carp, and lower economic value. For further explaination of algae and how it damages living organisms click here.
Eutrophication can be reduced or reversed by limiting the nutrients loading from municipal and industrial wastewaters, agricultural wastes and fertilizers. Natural eutrophication is impossible to control because of its vastness associated with it. For example, the ground water leaching through the surrounding soil will leach nutrients into the lake or reservoir. Controlling this leachate is virtually improbable and unnessecary. The majority of the nutrient loading is due to "man-made" sources stated previously."Man-made" eutrophication of inland water courses and coastal waters is caused by excessive discharge of nutrients, especially phosphorous and nitrogen. In Norway the nutrients come primarily from agricultural fertilization sewage, and fish farms along the coast. To further attack this problem itis important to understand the quantitative relationship between supply and degree of eutrophication. Strict lake management strategies must be developed in order to obtain the desired water quality. One strategy to reduce the degree of eutrophication in freshwater and coastal environments is to limit the addition of phosphorous and nitrogen entering the waters from point loadings. This would mean imposing regulations on industries, municipalities ,and homeowners in the watershed that is being affected by eutrophication.
Present day analysis of eutrophication can be modeled by computers. Through the use of GIS and GPS three dimensional models can be produced to better observe the extent of eutrophication in an affected water body. An example of this three dimensional computer modeling is being used in the Chesapeake Bay area.