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How A Massive Red Tide Event Makes For Glowing Blue Waves

A spray of light blue rolls to shore from the ocean
Newport Beach, 2021
(Courtesy Mark Girardeau / Orange County Outdoors)
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While you shouldn't be at the beach right now, there is something special happening in the ocean.

The coast from Monterey Bay to the Mexican border is experiencing what's commonly known as a red tide event. It's caused by a massive bloom of microscopic algae, which usually happens around this time of year and into late summer.

And, that's what's giving the waters off the South Bay and Long Beach a distinctively brownish-red color.

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When the bloom is disturbed — like when a boat motors through it, or if it's caught in some crashing surf — it can produce a soft, bright blue light.

The bioluminescence showed up in the San Diego area last week, and along some Orange and L.A. County beaches in recent days. But there's no way to predict when or where it will show up again.

Fortunately, the algae species in Southern California isn't toxic, but some blooms can cause eye and skin irritation.

Mark Girardeau, who owns Orange County Outdoors captured the rare neon blue waves created by a bioluminescent tide from the sand in Newport Beach on April 15 and gave us permission to share some of those images.

(Courtesy of Mark Girardeau)
(Courtesy of Mark Girardeau)
(Courtesy of Mark Girardeau)
(Courtesy of Mark Girardeau)

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