Editing Eutrophication (section)

===Nutrient bioextraction===
Nutrient bioextraction is bioremediation involving cultured plants and animals. Nutrient bioextraction or bioharvesting is the practice of farming and harvesting [[shellfish]] and [[seaweed]] to remove nitrogen and other nutrients from natural water bodies.<ref>{{cite web|title=Nutrient Bioextraction Overview|url=http://longislandsoundstudy.net/issues-actions/water-quality/nutrient-bioextraction-overview/|access-date=March 22, 2018|publisher=Long Island Sound Study partnership|location=Stamford, Conn.|archive-date=October 6, 2017|archive-url=https://web.archive.org/web/20171006062352/http://longislandsoundstudy.net/issues-actions/water-quality/nutrient-bioextraction-overview/|url-status=live}}</ref>

==== Shellfish in estuaries ====
[[File:Mussels at Strawberry Rocks PC013145.JPG|thumb|Mussels are an example of organisms that act as nutrient bioextractors. They consume the nitrogen in water, depleting algae of their nutrients.|231x231px]]
{{See also|Nutrient pollution}}It has been suggested that nitrogen removal by oyster reefs could generate net benefits for sources facing nitrogen emission restrictions, similar to other nutrient trading scenarios. Specifically, if oysters maintain nitrogen levels in estuaries below thresholds, then oysters effectively stave off an enforcement response, and compliance costs parties responsible for nitrogen emission would otherwise incur.<ref>{{cite web|last=Kroeger|first=Timm|year=2012|title=Dollars and Sense: Economic Benefits and Impacts from two Oyster Reef Restoration Projects in the Northern Gulf of Mexico|url=http://www.nature.org/ourinitiatives/regions/northamerica/oyster-restoration-study-kroeger.pdf|url-status=dead|archive-url=https://web.archive.org/web/20160304002313/http://www.nature.org/ourinitiatives/regions/northamerica/oyster-restoration-study-kroeger.pdf|archive-date=March 4, 2016|access-date=May 29, 2013|publisher=The Nature Conservancy}}</ref> Several studies have shown that oysters and mussels can dramatically impact nitrogen levels in estuaries.<ref>{{cite book| vauthors = Newell RI, Fisher TR, Holyoke RR, Cornwell JC |title=The Comparative Roles of Suspension Feeders in Ecosystems | volume = 47 |publisher=Springer|year=2005| veditors = Dame R, Olenin S |edition=NATO Science Series IV: Earth and Environmental Sciences|location=Netherlands|pages=93–120|contribution=Influence of eastern oysters on nitrogen and phosphorus regeneration in Chesapeake Bay, USA}}</ref><ref>{{cite book| vauthors = Grabowski JH, Petersen CM |title=Restoring oyster reefs to recover ecosystem services|publisher=Elsevier-Academic Press|year=2007| veditors = Cuddington K, Byers JE, Wilson WG, Hastings A |edition=Ecosystem Engineers: Concepts, Theory and Applications|location=Amsterdam|pages=281–298}}</ref><ref>{{cite web|year=2010|title=International Workshop on Bioextractive Technologies for Nutrient Remediation Summary Report|url=http://www.nefsc.noaa.gov/nefsc/publications/|publisher=US Dept Commerce, Northeast Fish Sci Cent Ref Doc. 10-19; 12 p. Available from: National Marine Fisheries Service, 166 Water Street, Woods Hole, MA 02543-1026|vauthors=Rose JM, Tedesco M, Wikfors GH, Yarish C|access-date=February 15, 2022|archive-date=October 29, 2019|archive-url=https://web.archive.org/web/20191029030853/https://www.nefsc.noaa.gov/nefsc/publications/|url-status=live}}</ref> Filter feeding activity is considered beneficial to water quality<ref>Burkholder, JoAnn M. and Sandra E. Shumway. (2011) "Bivalve shellfish aquaculture and eutrophication", in ''Shellfish Aquaculture and the Environment''. Ed. Sandra E. Shumway. John Wiley & Sons, {{ISBN|0-8138-1413-8}}.</ref> by controlling phytoplankton density and sequestering nutrients, which can be removed from the system through shellfish harvest, buried in the sediments, or lost through [[denitrification]].<ref>{{Cite journal|last1=Kaspar|first1=H. F.|last2=Gillespie|first2=P. A.|last3=Boyer|first3=I. C.|last4=MacKenzie|first4=A. L.|year=1985|title=Effects of mussel aquaculture on the nitrogen cycle and benthic communities in Kenepuru Sound, Marlborough Sounds, New Zealand|journal=Marine Biology|volume=85|issue=2|pages=127–136|doi=10.1007/BF00397431|bibcode=1985MarBi..85..127K |s2cid=83551118}}</ref><ref>{{Cite journal|last1=Newell|first1=R. I. E.|last2=Cornwell|first2=J. C.|last3=Owens|first3=M. S.|year=2002|title=Influence of simulated bivalve biodeposition and microphytobenthos on sediment nitrogen dynamics: A laboratory study|journal=Limnology and Oceanography|volume=47|issue=5|pages=1367–1379|bibcode=2002LimOc..47.1367N|doi=10.4319/lo.2002.47.5.1367|doi-access=free}}</ref> Foundational work toward the idea of improving marine water quality through shellfish cultivation was conducted by Odd Lindahl et al., using [[mussels]] in Sweden.<ref>{{Cite journal|last1=Lindahl|first1=O.|last2=Hart|first2=R.|last3=Hernroth|first3=B.|last4=Kollberg|first4=S.|last5=Loo|first5=L. O.|last6=Olrog|first6=L.|last7=Rehnstam-Holm|first7=A. S.|last8=Svensson|first8=J.|last9=Svensson|first9=S.|last10=Syversen|first10=U.|year=2005|title=Improving marine water quality by mussel farming: A profitable solution for Swedish society|url=http://www.aquacircle.org/images/pdfdokumenter/efterret07/ambi3402_131-138.pdf|journal=Ambio|volume=34|issue=2|pages=131–138|citeseerx=10.1.1.589.3995|doi=10.1579/0044-7447-34.2.131|pmid=15865310|bibcode=2005Ambio..34..131L |s2cid=25371433|access-date=November 1, 2017|archive-date=September 22, 2017|archive-url=https://web.archive.org/web/20170922011833/http://www.aquacircle.org/images/pdfdokumenter/efterret07/ambi3402_131-138.pdf|url-status=live}}</ref> In the United States, shellfish restoration projects have been conducted on the East, West and Gulf coasts.<ref>Brumbaugh, R.D. et al. (2006). [http://www.conservationgateway.org/Files/Pages/practitioner%E2%80%99s-guide-desi.aspx A Practitioners Guide to the Design and Monitoring of Shellfish Restoration Projects: An Ecosystem Services Approach] {{Webarchive|url=https://web.archive.org/web/20130701024305/http://www.conservationgateway.org/Files/Pages/practitioner%E2%80%99s-guide-desi.aspx |date=July 1, 2013 }}. The Nature Conservancy, Arlington, Va.</ref>

====Seaweed farming====
Studies have demonstrated seaweed's potential to improve nitrogen levels.<ref>{{Cite journal |last1=Kim |first1=Jang K. |last2=Kraemer |first2=George P. |last3=Yarish |first3=Charles |date=2014 |title=Field scale evaluation of seaweed aquaculture as a nutrient bioextraction strategy in Long Island Sound and the Bronx River Estuary |journal=Aquaculture |volume=433 |pages=148–156 |bibcode=2014Aquac.433..148K |doi=10.1016/j.aquaculture.2014.05.034}}</ref><ref>{{cite web |last1=Kroeger |first1=Timm |date=May 2012 |title=Dollars and Sense: Economic Benefits and Impacts from two Oyster Reef Restoration Projects in the Northern Gulf of Mexico |url=https://www.conservationgateway.org/Files/Pages/dollars-and-sense-economi.aspx |url-status=live |archive-url=https://web.archive.org/web/20200803151420/http://www.conservationgateway.org/Files/Pages/dollars-and-sense-economi.aspx |archive-date=August 3, 2020 |access-date=July 29, 2020 |publisher=The Nature Conservancy}}</ref>  [[Seaweed farming|Seaweed aquaculture]] offers an opportunity to mitigate, and adapt to climate change.<ref>{{cite journal|last1=Duarte|first1=Carlos M.|last2=Wu|first2=Jiaping|last3=Xiao|first3=Xi|last4=Bruhn|first4=Annette|last5=Krause-Jensen|first5=Dorte|date=April 12, 2017|title=Can Seaweed Farming Play a Role in Climate Change Mitigation and Adaptation?|journal=Frontiers in Marine Science|volume=4|page=100 |doi=10.3389/fmars.2017.00100|doi-access=free|bibcode=2017FrMaS...4..100D |hdl=10754/623247|hdl-access=free}}</ref> Seaweed, such as kelp, also absorbs phosphorus and nitrogen<ref>{{Cite web|url=https://e360.yale.edu/features/new_breed_of_ocean_farmer_aims_to_revive_global_seas|title=Can We Save the Oceans By Farming Them?|website=Yale E360|access-date=March 8, 2019|archive-date=October 19, 2019|archive-url=https://web.archive.org/web/20191019150923/https://e360.yale.edu/features/new_breed_of_ocean_farmer_aims_to_revive_global_seas|url-status=live}}</ref> and is thus helpful to remove excessive nutrients from polluted parts of the sea.<ref>{{Cite journal|last1=Xiao|first1=X.|last2=Agusti|first2=S.|last3=Lin|first3=F.|last4=Li|first4=K.|last5=Pan|first5=Y.|last6=Yu|first6=Y.|last7=Zheng|first7=Y.|last8=Wu|first8=J.|last9=Duarte|first9=C. M.|year=2017|title=Nutrient removal from Chinese coastal waters by large-scale seaweed aquaculture|journal=Scientific Reports|volume=7|pages=46613|bibcode=2017NatSR...746613X|doi=10.1038/srep46613|pmc=5399451|pmid=28429792}}</ref> Some cultivated seaweeds have very high productivity and could absorb large quantities of N, P, {{CO2}}, producing large amounts of {{chem2|O2}} having an excellent effect on decreasing eutrophication.<ref>{{Citation|last=Duarte|first=Carlos M.|title=Coastal eutrophication research: A new awareness |date=2009|work=Eutrophication in Coastal Ecosystems|pages=263–269|publisher=Springer Netherlands|doi=10.1007/978-90-481-3385-7_22|isbn=978-90-481-3384-0}}</ref> It is believed that seaweed cultivation in large scale should be a good solution to the eutrophication problem in [[coastal waters]].