Effects Of Eutrophication On Coastal Waters

1977 Words8 Pages
Eutrophication is defined as excessive richness of nutrients in a lake or other body of water. It is frequently due to runoff from the land, which causes a dense growth of plant life and, a subsequent death of animal life from a concentration lack of oxygen resulting from the oxidation of organic matter (Chrislock et al., 2013). Eutrophic systems can be observed to have shallow waters, high concentrations of nutrients, high productivity, and high oxygen usage. This process of eutrophication occurs naturally and is caused primarily by the accumulation of nitrogen and phosphorus. Waters that go through the process of eutrophication have a tendancy to move towards hypoxia or even anoxia. Hypoxic waters have 2-3 ppm of dissoled oxygen and anoxic waters having no dissolved oxygen. Although waters can undergo eutrophication naturally, it can also be accelerated by anthropogenic means. This human caused acceleration is refered to as cultural eutrophication. Eutrophication has many adverse effects, which is why it is not an ideal process for coastal waters. This essay will cover various causes and effects of eutrophication on coastal waters as well as the dilemna of controlling cultural eutrophication. The major contributor to eutrophication is the accumulation of nutrients, primarily nitrogen and phosphorous. One of these nutrients is often the limiting factor to primary production. Ocean water is typicall nitrogen limited and fresh water is typically phosphorous limited. However, when nutrients accumulate, primary production rate increases, and dissolved oxygen is intially reduced, then is consumed rapidly for the respiration of organic matter. This process shows that although these nutrients are essential for life, they can also have... ... middle of paper ... ... the problem. We know the cause of eutrophication: the overaccumulation of nitrogen and phosphorous in waters. Much of these nutrients derive from human activity, such as farming, urban runoff, and the burning of fossil fuels. We know the effect of eutrophication: the increase in nutrients leads to large phytoplankton blooms which degrade water quality. When these blooms die off, the decomposition of the dead algae potentially reduces dissolved oxygen in that area to hypoxic or even anoxic levels. The over consumption of oxygen can then lead to fish kills, alter ecosystem composition, inhibit life (excluding anaerobic organisms), and affect how we are able to use these waters. With this in mind, it seems clear that efforts should be made to look into ways of reducing and managing sources of cultrual eutrophication, for the improvement of water quality in the future.
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