phytoplankton
noun
phy·to·plank·ton
ˌfī-tō-ˈplaŋ(k)-tən 
-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
O. BakerPhytoplankton—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
Robert RidingPhytoplankton 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
Robin George AndrewsAntarctic krill are thumb-sized crustaceans that feast on drifting phytoplankton …—Usha Lee McFarling
compare zooplankton
Usha Lee McFarlingExamples of phytoplankton in a Sentence
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Tiny algae called phytoplankton release gases that cascade changes in the atmosphere.
—Max G. Levy, Smithsonian Magazine, 26 June 2025
An image of a massive bloom of phytoplankton captured from space by NASA's PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite.
—Soo Kim, MSNBC Newsweek, 25 June 2025
Since phytoplankton are at the base of the food chain, it can be used to determine the presence of fish, too, Lozier said.
—Julia Jacobo, ABC News, 19 June 2025
The culprit, the paper suggests, is the teeny tiny plant-like creatures that form the building blocks of the marine food web — phytoplankton.
—Alex Harris, Miami Herald, 19 June 2025
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Max G. Levy, Smithsonian Magazine, 26 June 2025
An image of a massive bloom of phytoplankton captured from space by NASA's PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite.
—Soo Kim, MSNBC Newsweek, 25 June 2025
Since phytoplankton are at the base of the food chain, it can be used to determine the presence of fish, too, Lozier said.
—Julia Jacobo, ABC News, 19 June 2025
The culprit, the paper suggests, is the teeny tiny plant-like creatures that form the building blocks of the marine food web — phytoplankton.
—Alex Harris, Miami Herald, 19 June 2025
See All Example Sentences for phytoplankton
Cite this Entry
“Phytoplankton.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phytoplankton. Accessed 14 Jul. 2025.
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phytoplankton
noun
phy·to·plank·ton
ˌfī-tō-ˈplaŋ(k)-tən
-ˌtän
: plankton that is composed of plants
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