Eutrophication is the phenomenon caused by the increasing amount of nutrients in the water bodies which results to the decrease in the oxygen concentration and death of aquatic animals. The main nutrient which commonly caused eutrophication in some of the water bodies is the phosphates. In this process, nutrients from soil are carried to the water bodies through erosion (Chislock et al., 2013). The high amounts of nutrients in the water bodies results to the increase in aquatic plants and algae such as the phytoplankton. The decay of these plants and algae converts oxygen to other by-products resulting to the decrease in oxygen concentration within the water bodies.
The main pollutants in this process are phosphate containing substances such as nutrients, fertilizers and detergents. The source of the pollutant could be natural source or human source. The natural source of the pollutant is the phosphates which are commonly occurring in the soil such as soil nutrients containing nitrogen (Smith et al., 1999). However, this process is extremely slow compared to anthropogenic eutrophication process. The human sources could be fertilizers which come from agricultural lands and detergents which come from sewage systems.
The pollutant in the eutrophication process could be classified as point-sources and non-point sources. The point sources of eutrophication include wastewater effluents from industrial and agricultural sites, untreated sewage and effluents from mining or oil fields. On the other hand, the non-point sources of pollutants which could result to eutrophication include agricultural runoffs, atmospheric deposition and runoffs from abandoned mining and oil fields (Chislock et al., 2013). In general, point sources could directly be attributed to the process of eutrophication and could easily be regulated through policies and environmental strategies.
Eutrophication could result to harmful effects on humans as well as to the environment (Smith et al., 1999). First, eutrophication could result to large amounts of aquatic animal deaths. The deaths of these aquatic animals could also result to the decrease of the population of animals which feeds on fishes and other aquatic living things. In this case, eutrophication could result to the unbalancing of animal population and disturbance of ecological diversity. On the other hand, eutrophication could also affect humans since some people also rely on fishes from water bodies. In addition, eutrophication could result to contamination of other water bodies especially if the water bodies are interconnected.
One of the main processes to eliminate the pollutants which cause eutrophication and mitigate its effect on human as well as to the environment is the phosphorus removal on water bodies such as lakes and rivers. In most cases, phosphates are removed from the discharges coming from agricultural and industrial sites (Smith et al., 1999). On other places, shellfishes are used for nutrient remediation which removes the nutrients from the water bodies and avoid the process of eutrophication.
In the United States, local and federal policies such as the Clean Water Act are used by the Environmental Protection Agency (EPA) in regulating the amounts of phosphates in agricultural and industrial sites (Chislock et al., 2013). In general, these policies have been successful in preventing the process of eutrophication. However, eutrophication still occurs in some areas due to the non-point sources. Other future options to avoid eutrophication would be the regulation of the organic farming practices and the use of fertilizers. In order to regulate the water discharges from these areas, nitrogen testing should be used in order to account for the phosphates.
References
Chislock, M.F., Doster, E., Zitomer, R.A. & Wilson, A.E. (2013). Eutrophication: Causes, Consequences, and Controls in Aquatic Ecosystems. Nature Education Knowledge, 4(4):1-10
Smith, V., Tilman, G., Nekola, J. (1999). Eutrophication: impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems. Environmental Pollution, 100: 179-196.
