San Diego beach-goers might be treated to the beauty of bioluminescence in local waters

A plankton bloom produce bioluminescent light in La Jolla in spring 2020.
(Eriki Jepsen/UC San Diego )

San Diego County beach-goers should be on the lookout for bioluminescence, a harmless phenomenon that causes ocean waters to sparkle at night with enchanting neon blue light.

Bioluminescence has been spotted in recent days in the Dana Point, Newport Beach and Laguna Beach sections of Orange County.

There was a little bit of it in the La Jolla area about three weeks ago, and it could return and possibly spread, which is not unusual in spring.

“We are seeing good numbers of the organisms that cause bioluminescence but they aren’t as dense in the surf zone as they were last year,” said Clarissa Anderson, executive director of UC San Diego’s Southern California Coastal Ocean Observing System.

The county experienced widespread bioluminescence last year, drawing crowds to local beaches.

The phenomenon is caused by single-cell organisms in plankton blooms that produce a chemical reaction that generates fleeting flashes of light, especially in breaking surf.