Other Life Forms

Dinoflagellates and Bioluminescence

What is bioluminescence?

Chemical reactions within an organism release energy that create a light which we call bioluminescence. Bioluminescence occurs mainly in the marine environment, but it also can occur on land in organisms such as fireflies, beetle larvae, and even mushrooms. Bioluminescence is typically blue or green in color, but red and yellow colors have also been documented.

It's a cool phenomenon, but what is its practical function?

Researchers have discovered some of the main reasons why organisms use bioluminescence:

  1. Finding or attracting food.
  2. Avoiding becoming food.
  3. Communication for mating.

Further research may uncover more uses. Scientist, deep-sea explorer, and specialist in marine bioluminescence Edith Wilder calls bioluminescence a "language of light." A language which will require much more scientific study to decode its many possible meanings.

Where can I see bioluminescence?

Tomales Bay is one of the more popular bodies of water in which to see bioluminescence, but bioluminescence can be seen anywhere along the National Seashore's coastline.

When can I see bioluminescence?

The best times for viewing bioluminescence is in the summer and fall on dark, cloudy nights before the moon has risen or after it sets. Be sure to use flashlights or headlamps with red LEDs or red filters to better preserve your night vision— avoid using white light at night when attempting to view bioluminescence (or stars in the night sky).

What causes this phenomenon in Tomales Bay?

Microscopic, single-celled organisms called dinoflagellates produce and emit light through a chemical reaction process. A common name for these organisms is sea sparkle. The scientific name is Noctiluca scintillans, which means glistening night light. When these organisms are moved by waves or the paddle of a kayak or canoe, the light becomes visible.

Want to know more?

Dinoflagellates are a type of plankton that has characteristics of both plants and animals. They drift with the currents and move using two flagella. They also make their own food using photosynthesis.

Very little, if any, heat is generated as a byproduct of the chemical reations which cause bioluminescence.

Scientist Edith Widder calls the emission of light a "bioluminescent burglar alarm."

Seasonal employee Marie Wright researched content and drafted text for this page.

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Last updated: November 25, 2023

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