Editing Plankton (section)

{{Short description|Organisms living in water or air that are drifters on the current or wind}}
{{About|the marine organisms|other uses}}
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[[File:Marine microplankton.jpg|thumb|upright=1.35| {{center|'''[[Marine microplankton|Marine microplankton and mesoplankton]]'''}} Part of the contents of one dip of a [[hand net]]. The image contains diverse planktonic organisms, ranging from [[photosynthetic]] [[cyanobacteria]] and [[diatom]]s to many different types of [[zooplankton]], including both [[holoplankton]] (permanent residents of the plankton) and [[meroplankton]] (temporary residents of the plankton, e.g., [[fish egg]]s, crab larvae, worm larvae).]]

'''Plankton''' are the diverse collection of [[organism]]s that drift in [[Hydrosphere|water]] (or [[atmosphere|air]]) but are unable to actively propel themselves against [[ocean current|current]]s (or [[wind]]).<ref>{{cite book |last1 = Lalli |first1 = C. |last2=Parsons |first2=T. |year=1993 |title=Biological Oceanography: An Introduction |publisher = Butterworth-Heinemann |isbn = 0-7506-3384-0}}</ref><ref>{{cite journal |last=Smith |first=David J. |date=July 2013 |title=Aeroplankton and the Need for a Global Monitoring Network |journal=BioScience |volume=63 |issue=7 |pages=515–516 |s2cid=86371218 |doi=10.1525/bio.2013.63.7.3 |doi-access=free }}</ref> The individual organisms constituting plankton are called '''plankters'''.<ref>{{cite web |title=plankter |url=https://www.ahdictionary.com/word/search.html?q=plankter |website=American Heritage Dictionary |publisher=Houghton Mifflin Harcourt Publishing Company |access-date=9 November 2018 |archive-url=https://web.archive.org/web/20181109153109/https://www.ahdictionary.com/word/search.html?q=plankter |archive-date=9 November 2018 |url-status=dead }}</ref> In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as [[bivalve]]s, [[fish]], and [[baleen whale]]s.

Marine plankton include [[bacteria]], [[archaea]], [[algae]], [[protozoa]], microscopic [[fungi]],<ref name="Lawton-2024-02-10">{{cite journal |last1=Lawton |first1=Graham |title=Fungi ahoy! |journal=New Scientist |date=10 February 2024 |volume=261 |issue=3477 |pages=37–39 |doi=10.1016/S0262-4079(24)00274-4|bibcode=2024NewSc.261b..37L }}</ref> and drifting or floating [[animal]]s that inhabit the [[saltwater]] of [[ocean]]s and the [[brackish]] waters of [[estuaries]]. [[fresh water|Freshwater]] plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like [[jellyfish]], swim slowly but not fast enough to generally overcome the influence of currents.

Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the atmosphere. These ''[[aeroplankton]]'' include [[plant spore]]s, [[pollen]] and wind-scattered [[seed]]s. They may also include microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by [[sea spray]].

Though many planktonic [[species]] are [[microscopic scale|microscopic]] in size, ''plankton'' includes organisms over a wide range of sizes, including large organisms such as jellyfish.<ref>{{cite web |url= http://www.institut-ocean.org/images/articles/documents/1354542960.pdf |title= Microzooplankton: the microscopic (micro) animals (zoo) of the plankton |last=Dolan |first=John |date= November 2012 |publisher=[[Institut océanographique]] |access-date=16 January 2014 |archive-url= https://web.archive.org/web/20160304081019/http://www.institut-ocean.org/images/articles/documents/1354542960.pdf |archive-date=4 March 2016 |url-status= dead }}</ref> This is because plankton are defined by their [[ecological niche]] and level of [[motility]] rather than by any [[phylogenetics|phylogenetic]] or [[taxonomy (biology)|taxonomic]] classification. The "plankton" category differentiates these organisms from those that float on the water's surface, called ''[[neuston]],'' those that can swim against a current, called ''[[nekton]]'', and those that live on the deep sea floor, called ''[[benthos]]''.