brown tide


Definition of brown tide

: a large area of seawater discolored a usually murky brown by the presence of large numbers of single-celled algae (such as Aureococcus anophagefferens or Aureoumbra lagunensis)

Note: Brown tides are not known to be harmful to people or marine vertebrates but have been detrimental to eelgrass beds and the shellfish that spawn there.

A brown tide, like the kind blamed for the collapse of the Long Island scallop industry in the 1980s, has bloomed in such high concentrations that it has turned one waterway black.— Anita Huslin, Wall Street Journal, 10 Aug. 2003 — compare red tide

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

First Known Use of brown tide

1986, in the meaning defined above

Keep scrolling for more

Learn More about brown tide

Time Traveler for brown tide

Time Traveler

The first known use of brown tide was in 1986

See more words from the same year

Statistics for brown tide

Cite this Entry

“Brown tide.” Dictionary, Merriam-Webster, Accessed 10 Aug. 2020.

Comments on brown tide

What made you want to look up brown tide? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Original Meanings Quiz

  • rembrandt painting a young scholar and his tutor
  • Which of the following is the earliest known sense of the word awe?
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!