phytoplankton

noun

phy·​to·​plank·​ton ˌfī-tō-ˈplaŋ(k)-tən How to pronounce phytoplankton (audio)
-ˌtän
plural phytoplankton also phytoplanktons
: minute aquatic photosynthetic organisms (such as dinoflagellates, diatoms, and cyanobacteria) : photosynthetic plankton of freshwater or marine environments
Twenty to 40 different species of phytoplankton … can coexist within a single cubic centimeter of water, all vying just for light and a handful of nutrients.O. Baker
Phytoplankton—myriad small, mostly unicellular algae and bacteria that occupy the surface waters of seas and lakes—dominate aquatic primary production, and over time they have radically altered Earth's atmosphere.Robert Riding
Phytoplankton form the foundation of marine food chains, and their seasonal blooms are responsible for more than half the photosynthesis, and the resulting production of oxygen, that occurs on Earth.Robin George Andrews
Antarctic krill are thumb-sized crustaceans that feast on drifting phytoplanktonUsha Lee McFarling
compare zooplankton
phytoplanktonic adjective
phytoplanktonic species
a phytoplanktonic bloom

Examples of phytoplankton in a Sentence

Recent Examples on the Web
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In other words, the data PACE has collected is improving our understanding about how Earth's atmosphere and oceans exchange carbon dioxide and reveal how aerosols might fuel phytoplankton growth in the surface ocean. Robert Z. Pearlman, Space.com, 15 May 2025 However, when algae bloom this time of year, the number of phytoplankton dramatically increases. Karen Garcia, Los Angeles Times, 10 May 2025 The onboard specialists guide the landings and shore excursions, including studying phytoplankton and native coral, implementing bird-strike reduction efforts and discovering new penguin colonies. Martie Bowser, Forbes.com, 1 May 2025 The molecules, dimethyl sulfide and potentially dimethyl disulfide, are typically made by marine phytoplankton on Earth. Ashley Strickland, CNN Money, 19 Apr. 2025 See All Example Sentences for phytoplankton

Word History

Etymology

phyto- + plankton

First Known Use

1897, in the meaning defined above

Time Traveler
The first known use of phytoplankton was in 1897

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Cite this Entry

“Phytoplankton.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phytoplankton. Accessed 27 May. 2025.

Kids Definition

phytoplankton

noun
phy·​to·​plank·​ton ˌfī-tō-ˈplaŋ(k)-tən How to pronounce phytoplankton (audio)
-ˌtän
: plankton that is composed of plants

More from Merriam-Webster on phytoplankton

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