Editing Plankton (section)

===Carbon cycle===
{{see also|ocean carbon cycle|biological pump}}

Primarily by grazing on phytoplankton, zooplankton provide [[carbon]] to the planktic [[foodweb]], either [[Cellular respiration|respiring]] it to provide [[metabolism|metabolic]] energy, or upon death as [[Biomass (ecology)|biomass]] or [[detritus]]. Organic material tends to be [[density|denser]] than [[seawater]], so it sinks into open ocean ecosystems away from the coastlines, transporting carbon along with it. This process, called the [[biological pump]], is one reason that oceans constitute the largest [[carbon sink]] on [[Earth science|Earth]]. However, it has been shown to be influenced by increments of temperature.<ref>{{cite journal |last1= Sarmento |first1= H. |last2= Montoya |first2= JM. |last3= Vázquez-Domínguez |first3= E. |last4= Vaqué |first4= D.|last5= Gasol |first5= JM. |year= 2010 |title= Warming effects on marine microbial food web processes: how far can we go when it comes to predictions? |pmc= 2880134 |journal= Philosophical Transactions of the Royal Society B: Biological Sciences |volume= 365 |issue=1549 |pages= 2137–2149 |doi= 10.1098/rstb.2010.0045 |pmid= 20513721 }}</ref><ref>{{cite journal |last1= Vázquez-Domínguez |first1= E. |last2= Vaqué |first2= D. |last3= Gasol |first3= JM. |year=2007 |title= Ocean warming enhances respiration and carbon demand of coastal microbial plankton. |journal= Global Change Biology |volume= 13 |issue=7 |pages= 1327–1334 |doi= 10.1111/j.1365-2486.2007.01377.x |bibcode= 2007GCBio..13.1327V |hdl= 10261/15731 |s2cid= 8721854 |hdl-access= free }}</ref><ref>{{cite journal |last1= Vázquez-Domínguez |first1= E. |last2= Vaqué |first2= D. |last3= Gasol |first3= JM. |year= 2012 |title= Temperature effects on the heterotrophic bacteria, heterotrophic nanoflagellates, and microbial top predators of NW Mediterranean. |journal= Aquatic Microbial Ecology |volume= 67 |issue=2 |pages= 107–121 |doi= 10.3354/ame01583 |doi-access= free |hdl= 10261/95626 |hdl-access= free }}</ref><ref>{{cite journal |last1= Mazuecos |first1= E. |last2= Arístegui |first2=J. |last3= Vázquez-Domínguez |first3= E. |last4= Ortega-Retuerta |first4= E. |last5= Gasol |first5= JM. |last6= Reche |first6= I. |year=2012 |title= Temperature control of microbial respiration and growth efficiency in the mesopelagic zone of the South Atlantic and Indian Oceans. |journal= Deep Sea Research Part I: Oceanographic Research Papers  |volume= 95 |issue=2 |pages= 131–138 |doi= 10.3354/ame01583 |doi-access= free |hdl= 10261/95626 |hdl-access= free }}</ref> In 2019, a study indicated that at ongoing rates of [[Ocean acidification|seawater acidification]], Antarctic phytoplanktons could become smaller and less effective at storing carbon before the end of the century.<ref>{{Cite web|url=https://phys.org/news/2019-08-acid-oceans-plankton-fueling-faster.html|title=Acid oceans are shrinking plankton, fueling faster climate change|last1=Petrou|first1=Katherina|last2=Nielsen|first2=Daniel|date=2019-08-27|website=phys.org|language=en-us|access-date=2019-09-07}}</ref>

It might be possible to increase the ocean's uptake of [[Carbon dioxide#In the Earth.27s atmosphere|carbon dioxide]] ({{chem|C|O|2}}) generated through [[Human impact on the environment|human activities]] by increasing plankton production through [[iron fertilization]] – introducing amounts of [[iron]] into the ocean. However, this technique may not be practical at a large scale. Ocean [[Anoxic sea water|oxygen depletion]] and resultant [[methanogen|methane production]] (caused by the excess production [[remineralisation|remineralising]] at depth) is one potential drawback.<ref>{{Cite journal   
| last1 = Chisholm |first1 = S.W. | year=2001   
| title = Dis-crediting ocean fertilization
| journal= Science | volume=294 | issue= 5541
| pages= 309–310 |doi= 10.1126/science.1065349
| pmid = 11598285
| last2 = Falkowski | first2 = PG   
| last3 = Cullen | first3 = JJ
|s2cid = 130687109 | display-authors = 1   
}}</ref><ref>{{Cite journal
 |last         = Aumont
 |first        = O.
 |author2      = Bopp, L.
 |year         = 2006
 |title        = Globalizing results from ocean ''in situ'' iron fertilization studies
 |journal      = Global Biogeochemical Cycles
 |volume       = 20
 |issue        = 2
 |doi          = 10.1029/2005GB002591
 |page         = GB2017
 |bibcode      = 2006GBioC..20.2017A
 |doi-access   = free
 }}</ref>