Plankton

Plankton includes organisms from species across all the major biological kingdoms, ranging in size from the [[microscopic scale|microscopic]] (such as [[bacteria]], [[archaea]], [[protozoa]] and microscopic [[algae]] and [[fungi]]{{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 }}) to larger organisms (such as jellyfish and ctenophores).{{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 }} 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 organisms from those that can swim against a current, called ''[[nekton]]'', and those that live on the deep sea floor, called ''[[benthos]]''. Organisms that float on or near the water's surface are called ''[[neuston]]''. Neuston that drift as water currents or wind take them, and lack the swimming ability to counter this, form a special subgroup of plankton. 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.

Plankton includes organisms from species across all the major biological kingdoms, ranging in size from the [[microscopic scale|microscopic]] (such as [[bacteria]], [[archaea]], [[protozoa]] and microscopic [[algae]] and [[fungi]]{{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 }}) to larger organisms (such as jellyfish and ctenophores).{{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 }} 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 organisms from those that can swim against a current, called ''[[nekton]]'', and those that live on the deep sea floor, called ''[[benthos]]''. Organisms that float on or near the water's surface are called ''[[neuston]]''. Neuston that drift as water currents or wind take them, and lack the swimming ability to counter this, form a special subgroup of plankton. 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.

Microscopic plankton, smaller than about one millimetre in size, play crucial roles in [[marine ecosystem]]s. They are a diverse group, which traditionally were divided into two [[Trophic level|trophic]] (feeding) groups: phytoplankton and zooplankton. [[Phytoplankton]], such as [[diatom]]s and some [[dinoflagellate]]s, synthesis their own food like plants on land, while [[zooplankton]], such as [[radiolarian]]s, [[foraminifera]] and [[copepod]]s, predate like animals on land and eat other life forms. In recent years, there has been a recognition that [[unicellular]] plankton often combine photosynthesis and ingestion within their single cell, such as ''[[Mesodinium]]'' and many dinoflagellates, which means they can act in both the above feeding modes. This has resulted in a third mode being recognized, that of [[mixoplankton]]. Together, these largely unseen microscopic plankton drive [[primary production]], support local food webs, cycle nutrients, and influence global biogeochemical processes. Their role is as a foundational component of the [[marine food web]], essential for maintaining the health and balance of marine ecosystems.

Microscopic plankton, smaller than about one millimetre in size, play crucial roles in [[marine ecosystem]]s. They are a diverse group, which traditionally were divided into two [[Trophic level|trophic]] (feeding) groups: phytoplankton and zooplankton. [[Phytoplankton]], such as [[diatom]]s and some [[dinoflagellate]]s, synthesis their own food like plants on land, while [[zooplankton]], such as [[radiolarian]]s, [[foraminifera]] and [[copepod]]s, predate and eat other life forms to get their food. In recent years, there has been a recognition that [[unicellular]] plankton often combine photosynthesis and ingestion within their single cell, such as ''[[Mesodinium]]'' and many dinoflagellates, which means they can act in both the above feeding modes. This has resulted in a third mode being recognized, that of [[mixoplankton]]. Together, these largely unseen microscopic plankton drive [[primary production]], support local food webs, cycle nutrients, and influence global biogeochemical processes. Their role is as a foundational component of the [[marine food web]], essential for maintaining the health and balance of marine ecosystems.

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]]'' can include [[plant spore]]s, [[pollen]] and wind-scattered [[seed]]s. They can also include microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by [[sea spray]].

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]]'' can include [[plant spore]]s, [[pollen]] and wind-scattered [[seed]]s. They can also include microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by [[sea spray]].