Editing Eutrophication (section)

==Prevention==
{{Further|Harmful algal bloom}}

As a society, there are certain steps we can take to ensure the minimization of eutrophication, thereby reducing its harmful effects on humans and other living organisms in order to sustain a healthy norm of living, some of which are as follows:

=== Minimizing pollution from sewage ===
{{Further|Nutrient pollution#Mitigation of nutrient pollutant discharges}}
There are multiple different ways to fix cultural eutrophication with raw sewage being a [[point source]] of pollution. For example, [[Sewage treatment|sewage treatment plants]] can be upgraded for biological nutrient removal so that they discharge much less nitrogen and phosphorus to the receiving water body. However, even with good [[secondary treatment]], most final effluents from sewage treatment works contain substantial concentrations of nitrogen as nitrate, nitrite or ammonia. Removal of these nutrients is an expensive and often difficult process.

Laws regulating the discharge and treatment of sewage have led to dramatic nutrient reductions to surrounding ecosystems.<ref name="Smith 1999">{{Cite journal |last1=Smith |first1=V. H. |last2=Tilman |first2=G. D. |last3=Nekola |first3=J. C. |year=1999 |title=Eutrophication: Impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems |journal=Environmental Pollution |volume=100 |issue=1–3 |pages=179–196 |doi=10.1016/S0269-7491(99)00091-3 |pmid=15093117 |s2cid=969039}}</ref> As a major contributor to the nonpoint source nutrient loading of water bodies is untreated domestic sewage, it is necessary to provide treatment facilities to highly urbanized areas, particularly those in [[Developing country|developing countries]], in which treatment of domestic waste water is a scarcity. The technology to safely and efficiently [[Reclaimed water|reuse wastewater]], both from domestic and industrial sources, should be a primary concern for policy regarding eutrophication.

=== Minimizing nutrient pollution by agriculture ===
There are many ways to help fix cultural eutrophication caused by agriculture. Some recommendations issued by the U.S. Department of Agriculture include:<ref name=":4">{{Cite web|date=March 12, 2013|title=The Sources and Solutions: Agriculture|url=https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture|url-status=live|archive-url=https://web.archive.org/web/20210622084443/https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture|archive-date=June 22, 2021|access-date=|publisher=United States EPA}}</ref>
# [[Nutrient management]] techniques - Anyone using fertilizers should apply fertilizer in the correct amount, at the right time of year, with the right method and placement. Organically fertilized fields can "significantly reduce harmful nitrate leaching" compared to conventionally fertilized fields.<ref name="PNAS 2006-3-21">{{Cite journal | doi = 10.1073/pnas.0600359103|bibcode = 2006PNAS..103.4522K | title = Reduced nitrate leaching and enhanced denitrifier activity and efficiency in organically fertilized soils | year = 2006 | last1 = Kramer | first1 = S. B. | journal = Proceedings of the National Academy of Sciences | volume = 103 | issue = 12 | pages = 4522–4527 | pmid=16537377 | pmc=1450204|doi-access = free }}</ref> Eutrophication impacts are in some cases higher from organic production than they are from conventional production.<ref>Williams, A.G., Audsley, E. and Sandars, D.L. (2006) [http://randd.defra.gov.uk/Default.aspx?Module=More&Location=None&ProjectID=11442 Determining the environmental burdens and resource use in the production of agricultural and horticultural commodities] {{Webarchive|url=https://web.archive.org/web/20180925104257/http://randd.defra.gov.uk/Default.aspx?Module=More&Location=None&ProjectID=11442 |date=September 25, 2018 }}. Main Report. Defra Research Project IS0205. Bedford: Cranfield University and Defra.</ref>  In Japan the amount of nitrogen produced by livestock is adequate to serve the fertilizer needs for the agriculture industry.<ref name="Kumazawa 2002">{{Cite journal | last1 = Kumazawa | first1 = K. | journal = Nutrient Cycling in Agroecosystems | volume = 63 | issue = 2/3 | pages = 129–137 | doi = 10.1023/A:1021198721003 |title=Nitrogen fertilization and nitrate pollution in groundwater in Japan: Present status and measures for sustainable agriculture| year = 2002 | bibcode = 2002NCyAg..63..129K | s2cid = 22847510 }}</ref>
# Year-round ground cover - a [[cover crop]] will prevent periods of bare ground thus eliminating erosion and runoff of nutrients even after the growing season has passed.
# Planting field buffers - Planting trees, shrubs and grasses along the edges of fields can help catch the runoff and absorb some nutrients before the water makes it to a nearby water body.<ref name="Carpenter, S.R. 1998">{{cite journal|last1=Carpenter|first1=S. R.|last2=Caraco|first2=N. F.|last3=Correll|first3=D. L.|last4=Howarth|first4=R. W.|last5=Sharpley|first5=A. N.|last6=Smith|first6=V. H.|date=August 1998|title=Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen|journal=Ecological Applications|volume=8|issue=3|pages=559|doi=10.2307/2641247|jstor=2641247|hdl-access=free|hdl=1813/60811}}</ref> [[riparian|Riparian buffer zones]] are interfaces between a flowing body of water and land, and have been created near waterways in an attempt to filter pollutants; [[sediment]] and nutrients are deposited here instead of in water. Creating buffer zones near farms and roads is another possible way to prevent nutrients from traveling too far. 
# [[Tillage#Conservation_tillage|Conservation tillage]] - By reducing frequency and intensity of tilling, the land will enhance the chance of nutrients absorbing into the ground.
[[File:Orange like Autumn.jpg|thumb|Eutrophication in a canal]]

===Policy===
The [[United Nations]] framework for [[Sustainable Development Goals]] recognizes the damaging effects of eutrophication for marine environments. It has established a timeline for creating an Index of Coastal Eutrophication and Floating Plastic Debris Density (ICEP) within [[Sustainable Development Goal 14]] (life below water).<ref name=":14">{{Cite web|title=14.1.1 Index of Coastal Eutrophication (ICEP) and Floating Plastic debris Density|url=https://uneplive.unep.org/indicator/index/14_1_1|access-date=October 14, 2020|website=UN Environment|archive-date=August 13, 2020|archive-url=https://web.archive.org/web/20200813115053/https://uneplive.unep.org/indicator/index/14_1_1|url-status=live}}</ref> SDG 14 specifically has a target to: "by 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution".<ref name=":17">{{Cite web|title=Goal 14 targets|url=https://www.undp.org/content/undp/en/home/sustainable-development-goals/goal-14-life-below-water/targets.html|url-status=dead|archive-url=https://web.archive.org/web/20200930060036/https://www.undp.org/content/undp/en/home/sustainable-development-goals/goal-14-life-below-water/targets.html|archive-date=September 30, 2020|access-date=September 24, 2020|publisher=UNDP|language=en}}</ref>

Policy and regulations are a set of tools to minimize causes of eutrophication.<ref name="ReferenceA">[http://www.unep.or.jp/ietc/Publications/TechPublications/TechPub-11/ "Planning and Management of Lakes and Reservoirs: An Integrated Approach to Eutrophication."] {{Webarchive|url=https://web.archive.org/web/20121111202652/http://www.unep.or.jp/ietc/Publications/techpublications/TechPub-11/ |date=November 11, 2012 }} United Nations Environment Programme, Newsletter and Technical Publications. International Environmental Technology Centre. Ch.3.4 (2000).</ref> Nonpoint sources of pollution are the primary contributors to eutrophication, and their effects can be minimized through common agricultural practices. Reducing the amount of pollutants that reach a watershed can be achieved through the protection of its forest cover, reducing the amount of erosion leeching into a watershed. Also, through the efficient, controlled use of land using sustainable agricultural practices to minimize [[land degradation]], the amount of soil runoff and nitrogen-based fertilizers reaching a watershed can be reduced.<ref>{{cite journal|author1=Oglesby, R. T.  |author2=Edmondson, W. T. |title=Control of Eutrophication|journal= Journal (Water Pollution Control Federation)|volume= 38|issue= 9 |year=1966|pages= 1452–1460|jstor=25035632}}</ref> Waste disposal technology constitutes another factor in eutrophication prevention.

The current policies proposed are mainly command-and-control policies, which are based on commonly used regulation standards. <ref name=":19">{{Cite journal |last1=Hammarlund |first1=Cecilia |last2=Andersson |first2=Anna |last3=Nordström |first3=Jonas |date=2024-04-02 |title=Nutrient policies and the performance of aquaculture in developed countries – a literature review |url=https://www.tandfonline.com/doi/full/10.1080/13657305.2024.2314511 |journal=Aquaculture Economics & Management |language=en |volume=28 |issue=2 |pages=208–237 |doi=10.1080/13657305.2024.2314511 |bibcode=2024AqEM...28..208H |issn=1365-7305}}</ref> Although these policies are easier to implement, they are not as cost-effective.<ref name=":19" /> This typically involves implementing limitations on input resources, emissions, or technologies, which are all common command-and-control policies that have been implemented by multiple countries. <ref name=":19" />

Because a body of water can have an effect on a range of people reaching far beyond that of the watershed, cooperation between different organizations is necessary to prevent the intrusion of contaminants that can lead to eutrophication. Agencies ranging from state governments to those of water resource management and non-governmental organizations, going as low as the local population, are responsible for preventing eutrophication of water bodies. In the United States, the most well known inter-state effort to prevent eutrophication is the [[Chesapeake Bay]].<ref>[https://web.archive.org/web/20150111125613/http://dnr.state.md.us/bay/monitoring/limit/index.html Nutrient Limitation]. Department of Natural Resources, Maryland, U.S.</ref>