Red tides create conditions that increase these "blooms" of dinoflagellates, possibly because of nutrients or hydrographic conditions in the ocean, but the cause is not entirely understood.
The red tides are unpredictable and not all produce a bioluminescence. A luminous glow lighted the wave approaching the beach surprising everyone.
The phenomenon is created when a red tide, which is algae bloom filled with phytoplankton called "dinoflagellates", rolls off waves onto or near the shoreline.
The waves along San Diego's coastline are lighting up with a bright blue glow.
"It's this bright electrical blue color and it's handsome", Jami Leslie Feldman, owner of Underwater Paparazzi, told the news station.
If you live in the area, Scripps says the best time to catch the bioluminescent activity is from a dark beach at least two hours after sunset.
The Patel Dam kills 34, several people still missing
Esipisu said: "We are saddened by the loss of lives and property occasioned by the bursting of Patel dam in Solai , Subukia". Military helicopters and personnel have for the past week been deployed to rescue people marooned by the flooding .
The Southern California Coastal Ocean Observing System at Scripps samples the water for potential harmful algal toxins weekly.
"The last time we had one was in September 2013, and the last big one was in October 2011", Michael Latz, a bioluminescence expert at UC San Diego's Scripps Institution of Oceanography, to told the San Diego Union-Tribune.
Monday's was known to stretch from La Jolla to Encinitas - and it's unknown how long it will last; it could be a week or a month.
"I was thinking, this is SoCal's equivalent of a Northern Lights", said Bay. "Just having natural phenomena where the lights are glowing and the water is lit up. I've never seen anything like it".
"This bloom, like many HABs, is caused by microscopic algae that produce toxins that kill fish and make shellfish unsafe to eat".
In Florida, the phytoplankton produce an air toxin that causes asthma-like symptoms, Latz said.