Bioluminescent Beasties Light Up California Beaches


Red tides and bright blue waves make SoCal glow. (San Jose Mercury News)

What is bioluminescence? Use our great resource as a go-to reference.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

The best time to see the bioluminescent beaches is at least two hours after sunset.
Photograph by Mike, courtesy Wikimedia. CC-BY-SA-2.0

Discussion Ideas


  • Why do dinoflagellates glow?
    • Not all of them do. The dinoflagellate species responsible for the glowing waves is Lingulodinium polyedra. (L. polyedra just got a new name this year. Read all about it here.)
    • The glowing dinoflagellates are bioluminescent, meaning chemical reactions within the organism itself can produce the organism’s own “living light.” The flashes of bioluminescence in the Southern California dinoflagellates are triggered by mechanical stress or agitation; even slight movement in the water around them can cause these creatures to glow.
      • Take a look at this video of surfers agitating millions of dinoflagellates in the coolest special effect you’ll see today.
    • Bioluminescence in dinoflagellates is a defense mechanism. “Dinoflagellate flashes cause a startle response in their predators, disrupting their feeding behavior and resulting in a decrease in grazing rate by reducing the number of dinoflagellates consumed. Dinoflagellate bioluminescence is also thought to act as a ‘burglar alarm’ to attract a secondary predator that threatens to eat the primary predator.”



Bioluminescence in dinoflagellates is produced by a chemical reaction in small structures called scintillons.
Illustration by Zina Deretsky, National Science Foundation
  • How do dinoflagellates glow? Browse our reference resource for some help—we even have a short section on dinoflagellates.
    • The chemical reaction that results in dinoflagellate bioluminescence requires two unique chemicals: luciferin and luciferase.
      • Luciferin is called the base or substrate. Dinoflagellates’ blue-green bioluminescent color is a result of the arrangement of luciferin molecules.
      • Luciferase is an enzyme. An enzyme is a chemical (called a catalyst) that interacts with a substrate to affect the rate of a chemical reaction.
      • Through an exchange of protons in cell structures called scintillons, the luciferin-luciferase reaction creates a flash of light.




San Jose Mercury News: What’s making the ocean glow blue at night at some California beaches?

Scripps Institution of Oceanography: Latz Laboratory—Dinoflagellate Bioluminescence

National Science Foundation: Suggested Explanation for Glowing Seas—Including Currently Glowing California Seas

Nat Geo: What is bioluminescence?

Nat Geo: Bioluminescence: Living Light

UCMP: Introduction to the Dinoflagellata

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