The process of eutrophication occurs when natural and artificial nutrients, mainly nitrates and phosphates, are found in an aquatic or terrestrial ecosystem. When these nutrients are added to a body of water or soil, the consequences can manifest in many forms. The growth of microscopic organisms known as phytoplankton (blue-green algae) in freshwater rivers and lakes flourishes when there is a supplement of nutrients. When there is an overabundance of them in a lake or river, they appear as a green color above the water. Excessive algae growth and weeds are two other results that can also occur when too many nutrients enter a body of water. There are two types of eutrophication, natural and cultural, that occur in bodies of water. Natural eutrophication occurs at a much slower rate and can take up to a century for results to be visible. Whereas cultural eutrophication is the more damaging of the two and usually occurs within a few decades. This is due to excessive accumulation of nutrients at a much faster rate caused by human error. Cultural eutrophication occurs when runoff, which contains nitrates and phosphates, moves from one place to another and ends up in a river or lake. Unfortunately, sometimes these nutrients end up leaching into groundwater. Sometimes eutrophication can be severe enough to cause a significant drop in oxygen in these water bodies. The results of this are visible in the detrimental effect it has on aquatic fauna, creating what are called dead zones. Cultural eutrophication is a universally observed problem. Steps are being taken to combat the spread of eutrophication, while trying to reverse the damage it has caused to aquatic environments...... middle of paper ...... phication. Retrieved November 25, 2013 from www.lenntech.com/.../eutrophication-solutions.htmMack, J. (2013). Eutrophication. Lake scientist. Retrieved from http://www.lakescientist.com/.../waterquality/eutrophication.html.Rast, W. and Thornton, JA (1996). Trends in eutrophication research and control. Hydrological Processes, 10(2), 295-313. Smith, VH, Joye, SB and Howarth, RW (2006). Eutrophication of freshwater and marine ecosystems. Limnology and Oceanography, 51(1), 351-355. Smith, VH, Tilman, GD and Nekola, JC (1999). Eutrophication: impacts of excessive nutrient inputs on freshwater, marine and terrestrial ecosystems. Environmental pollution,100(1), 179-196. United States Department of Commerce (1996). Eutrophication. Retrieved from the NationalOceanic and Atmospheric Administration website: www.nerrs.noaa.gov/.../watqual/wmeutro.htm.