Neon waves captured in Southern California

DANA POINT—A unique phenomenon was photographed up and down the Southern California coast in late April. Photos posted on social media from San Diego to Newport Beach captured blue neon waves caused by the annual return of the red tide and bioluminescence phenomenon.

The Orange County Sheriff’s Department Harbor Patrol posted a photo on Instagram on April 17 of a boat wake turned neon against the rest of the pitch-dark ocean in Dana Point. Many other photos were shared on social media of glowing breaking waves.

The phenomenon happens when phytoplankton called “dinoflagellates” react with bioluminescence when jostled by the moving water. Red tides are unpredictable and not all of them produce bioluminescence.

According to Southern California Coastal Ocean Observing Systems, Harmful Algal Bloom monitoring program (SCCOOS HAB), there’s currently Lingulodinium polyedra in the water, also known as L .poly. The bioluminescent species is a dinoflagellate causing the red bands seen in coastal waters.

It’s unclear exactly how long red tides last. In the past, algae blooms have lasted anywhere between a week to a month, according to researchers.