Surfers, kayakers, and others in San Diego, California, were happy to witness a beautiful sight up close this week.
What caused this unusual phenomenon? It was caused by a tiny organism called Lingulodinium polyedrum, which is a type of algae that blooms every few years in the waters around San Diego.
Michael Latz, a scientist at Scripps Institution of Oceanography at UC San Diego, noted that movement in the water causes the aggregations of dinoflagellates to glow neon blue at night.
Previous instances of the blue tides have lasted anywhere from one week to more than a month, according to Scripps.
Video Credit: Wochit Media