red tide
noun
: 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
Last summer, for example, a red tide bloom released a neurotoxin called domoic acid that sickened sea lions and other marine mammals along the California coast, including in Los Angeles.
—
Clara Harter, Los Angeles Times, 30 Oct. 2024
Officials are also monitoring a plume of red tide off the coast, WUSF reported.
—Kathryn Varn, Axios, 25 Oct. 2024
Advertisement But red tides — and coordinating biolumenescence — are unpredictable and quite fickle, according to UC San Diego’s Scripps Institution of Oceanography.
—Grace Toohey, Los Angeles Times, 22 Oct. 2024
The organism that causes red tide is toxic and can affect the central nervous system of fish, often killing them.
—Kinsey Crowley, USA TODAY, 7 Mar. 2024
See all Example Sentences for red tide 
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Clara Harter, Los Angeles Times, 30 Oct. 2024
Officials are also monitoring a plume of red tide off the coast, WUSF reported.
—Kathryn Varn, Axios, 25 Oct. 2024
Advertisement But red tides — and coordinating biolumenescence — are unpredictable and quite fickle, according to UC San Diego’s Scripps Institution of Oceanography.
—Grace Toohey, Los Angeles Times, 22 Oct. 2024
The organism that causes red tide is toxic and can affect the central nervous system of fish, often killing them.
—Kinsey Crowley, USA TODAY, 7 Mar. 2024
See all Example Sentences for red tide
Dictionary Entries Near red tide
Cite this Entry
“Red tide.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/red%20tide. Accessed 23 Nov. 2024.
Copy CitationMedical Definition
red tide
noun
: 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
Ellen GirardeauRed 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
Nicholas BakalarLove words? Need even more definitions?
Merriam-Webster unabridged
Share