red tide

noun

Definition of red tide

: seawater discolored by the presence of large numbers of dinoflagellates (as of the genera Karenia, Gymnodinium, and Alexandrium) which typically produce a toxin poisonous especially to many forms of marine vertebrate life and to humans who consume contaminated shellfish — compare saxitoxin

Examples of red tide in a Sentence

Recent Examples on the Web Three years ago, massive blooms of the red tide prompted some beaches to close. From Usa Today Network And Wire Reports, USA TODAY, 18 June 2021 There are also threats from red tide outbreaks — and unusually cold weather. Curt Anderson, sun-sentinel.com, 26 Oct. 2021 There are also threats from red tide outbreaks — and unusually cold weather. NBC News, 26 Oct. 2021 The move could avoid a disaster at the reservoir but could also have harmful effects such as red tide and fish kills in the bay. Laura L. Davis, USA TODAY, 5 Apr. 2021 Scientists wondered for months how that might affect red tide this year. New York Times, 28 July 2021 Some medium concentrations were found in Manatee County among 18 samples taken while 12 samples in Sarasota County suggest a medium concentration of red tide. Garfield Hylton, orlandosentinel.com, 25 June 2021 Three years ago, massive blooms of the red tide prompted some beaches to close. From Usa Today Network And Wire Reports, USA TODAY, 18 June 2021 The red tide affecting Massachusetts is different from the type killing fish in Florida, and swimming remains safe, Gloucester shellfish warden Peter Seminara said. From Usa Today Network And Wire Reports, USA TODAY, 19 July 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'red tide.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of red tide

1904, in the meaning defined above

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The first known use of red tide was in 1904

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Dictionary Entries Near red tide

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Last Updated

10 Dec 2021

Cite this Entry

“Red tide.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/red%20tide. Accessed 20 Jan. 2022.

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More Definitions for red tide

red tide

noun

Medical Definition of red tide

: a large area of seawater discolored by the presence of large numbers of dinoflagellates (as of the genera Karenia, Gymnodinium, and Alexandrium) which typically produce toxins poisonous especially to many forms of vertebrate marine life and to humans who consume contaminated shellfish In simple terms, a red tide is a dinoflagellate population explosion, caused when certain species "bloom," or multiply many times faster than usual.— Ellen Girardeau Red tides, the blooms of toxic Karenia brevis algae that appear almost every year in Florida, often lasting for months and turning the ocean red, may be dangerous to asthma sufferers—even if they don't go swimming.— Nicholas Bakalar — see brevetoxin, saxitoxin, shellfish poisoning

More from Merriam-Webster on red tide

Britannica.com: Encyclopedia article about red tide

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