Bioluminescent surf at San Diego beaches in September, 2011

San Diego County in California had a strong red tide this week, apparently peaking around September 28, 2011. The red tide – a discoloration of seawater caused by a bloom of tiny, toxic organisms known as red dinoflagellates – lit up the surf at night on San Diego beaches, via a phenomenon known as bioluminescence. Several videographers captured the strange light, visible at night in the breaking waves along San Diego shores.

This video – from cinemadv on YouTube – is short, but captures the phenomenon perfectly, although he (or she) commented the color was actually more greenish than blue. It was uploaded to YouTube on September 28, 2011.

This longer video comes from LoghanCall on YouTube. He wrote:

On September 28th, 2011, the “red tide” hit San Diego shores. The neon-blue waves are not digitally created or altered from their original form. This video was shot at Moonlight Beach in Encinitas, California and North Ponto Beach in Carlsbad, California.

The video above, uploaded to YouTube on September 27, is a bit dark, but you can see surfers in the bioluminescent surf. It’s from shuttrbg22.

Bioluminescent life forms – such as the tiny red dinoflagellates in the red tide shown in these videos – make their own light and carry it in their bodies. Fireflies are another, perhaps more commonly seen example. In the oceans of our world, though, many creatures are bioluminescent. Just as fireflies use their lit-up abdomens to send mating signals and other forms of communication, so bioluminescent creatures of the deep use their internal ability to create light to warn or evade predators, lure or detect prey, and communicate between species members.

Bottom line: During the last week of September, 2011, a red tide in southern California created bioluminescence along beaches near San Diego. The internally illuminated tide was seen for several nights, and some people captured good videos of the event.

Surf’s lighted up at San Diego beaches

Bioluminescent beaches photo gallery from

Why do fireflies light up?

Humboldt squid washing up on southern California beaches

There’s no such thing as a jellyfish

October 1, 2011

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Deborah Byrd

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