A Moonlit and Wavelit Night at Moonlight Beach, Encinitas California

An almost full blue moon graced Moonlight Beach on August 29th, 2023. Along with the moonlight there was a different kind of light coming from the water. At first it looked like the refection of moonlight but as you approached the shoreline a blue hue was observed that indicated the waves were being lighted from within.

Here are some choice video and images from that night:

This glowing wave phenomenon is caused by bioluminescent phytoplankton (aka microalgae or dinoflagellates). These glowing plankton are always present in ocean waters but only sometimes produce a 'bloom*' where they grow rapidly in a short period of time. This rapid growth along with cooperation from the tides and currents allows them to be seen from shore. The synergy of rapid growth, currents and tides are difficult to predict but generally occur after significant rainfall in the warmer months of the year (in Southern California). *An algal bloom is more commonly known as a redtide.

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