Cultural eutrophication

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Cultural eutrophication is the process that speeds up natural eutrophication because of human activity.[1] Due to clearing of land and building of towns and cities, land runoff is accelerated and more nutrients such as phosphates and nitrate are supplied to lakes and rivers, and then to coastal estuaries and bays. Extra nutrients are also supplied by treatment plants, golf courses, fertilizers, and farms.

These nutrients result in an excessive growth of plant life known as an algal bloom. This can change a lake's natural food web, and also reduce the amount of dissolved oxygen in the water for organisms to breathe. Both these things cause animal and plant death rates to increase as the plants take in poisonous water while the animals drink the poisoned water. This contaminates water, making it undrinkable, and sediment quickly fills the lake. Cultural eutrophication is a form of water pollution.

Cultural eutrophication also occurs when excessive fertilizers run into lakes and rivers. This encourages the growth of algae (algal bloom) and other aquatic plants. Following this, overcrowding occurs and plants compete for sunlight, space and oxygen. Overgrowth of water plants also blocks sunlight and oxygen for aquatic life in the water, which in turn threatens their survival. Algae also grows easily, thus threatening other water plants no matter whether they are floating, half-submerged, or fully submerged. Not only does this cause algal blooming, it can cause an array of more long-term effects on the water such as damage to coral reefs and deep sea animal life. It also speeds up the damage of both marine and also affects humans if the effects of algal blooming is too drastic. Fish will die and there will be lack of food in the area. Nutrient pollution is a major cause of algal blooming, and should be minimized.

The Experimental Lakes Area (ELA), Ontario, Canada is a fully equipped, year-round, permanent field station that uses the whole ecosystem approach and long-term, whole-lake investigations of freshwater focusing on cultural eutrophication. ELA is currently cosponsored by the Canadian Departments of Environment and Fisheries and Oceans, with a mandate to investigate the aquatic effects of a wide variety of stresses on lakes and their catchments [2][3]

Sources of Anthropogenic Pollution[edit]

Raw Sewage[edit]

The disposal of raw sewage into ocean waters is banned in many countries including the United States, but many developed countries such as Canada continue to pump untreated sewage waste into ocean waters.[4] This is a widespread and highly publicized issue ranging from west coast Victoria, British Columbia,[5] to east coast Nova Scotia.[6]


  1. ^ Cultural eutrophication (2010) Encyclopædia Britannica. Retrieved April 26, 2010, from Encyclopædia Britannica Online:
  2. ^ Schindler, David William (2009). "A personal history of the Experimental Lakes Project" (PDF). Canadian Journal of Fisheries and Aquatic Sciences. 66 (11): 1837–1847. doi:10.1139/f09-134. 
  3. ^ Schindler, David W., Vallentyne, John R. (2008). The Algal Bowl: Overfertilization of the World's Freshwaters and Estuaries, University of Alberta Press, ISBN 0-88864-484-1.
  4. ^ "Pollution of the Ocean by Sewage, Nutrients, and Chemicals - river, sea, oceans, percentage, types, system, plants, source, marine, oxygen, human, Pacific". Retrieved 2017-04-30. 
  5. ^ Roshini Nair (2016-09-14). "Decades of dumping raw sewage is killing Victoria's ocean floor, diver claims - British Columbia - CBC News". Retrieved 2017-04-30. 
  6. ^ Elizabeth Thompson (2016-12-12). "Billions of litres of raw sewage, untreated waste water pouring into Canadian waterways - Politics - CBC News". Retrieved 2017-04-30.