Editing Estuary (section)

=== Effects of eutrophication on human activities ===
[[File:Fishing_boat_at_Wrangell_Harbor.jpg|thumb|Commercial fishing boat]]
Eutrophication can affect many marine habitats which can lead to economic consequences. The commercial fishing industry relies upon estuaries for approximately 68 percent of their catch by value because of the great biodiversity of this ecosystem.<ref name=":4">{{Cite journal |last=Lellis-Dibble |first=K.A. |date=2008 |title=Estuarine Fish and Shellfish Species in US commercial and Recreational Fisheries: Economic Value as an Incentive to Protect and Restore Estuarine Habitat |journal=National Oceanic and Atmospheric Administration}}</ref> During an [[algal bloom]], fishermen have noticed a significant increase in the quantity of fish.<ref name=":3">{{Cite journal |last1=Gao |first1=Yang |last2=Lee |first2=Jeong-Yeol |date=2012-12-30 |title=Compensatory Responses of Nile Tilapia Oreochromis niloticus under Different Feed-Deprivation Regimes |journal=Fisheries and Aquatic Sciences |volume=15 |issue=4 |pages=305–311 |doi=10.5657/fas.2012.0305 |issn=2234-1749|doi-access=free }}</ref> A sudden increase in primary productivity causes spikes in fish populations which leads to more oxygen being utilized.<ref name=":3" /> It is the continued deoxygenation of the water that then causes a decline in fish populations. These effects can begin in estuaries and have a wide effect on the surrounding water bodies.  In turn, this can decrease fishing industry sales in one area and across the country.<ref>{{Cite journal |last1=Fay |first1=Gavin |last2=DePiper |first2=Geret |last3=Steinback |first3=Scott |last4=Gamble |first4=Robert J. |last5=Link |first5=Jason S. |date=2019 |title=Economic and Ecosystem Effects of Fishing on the Northeast US Shelf |journal=Frontiers in Marine Science |volume=6 |page=133 |doi=10.3389/fmars.2019.00133 |issn=2296-7745|doi-access=free |bibcode=2019FrMaS...6..133F }}</ref> Production in 2016 from recreational and commercial fishing contributes billions of dollars to the United States' gross domestic product (GDP).<ref name=":4" /> A decrease in production within this industry can affect any of the 1.7 million people the fishing industry employs yearly across the United States.