Glowing neon blue waves are back along the Southern California coast

With each wave that crashes, a pulse of bright blue neon electrifies the dark waters, lighting up the whitewash as it crumbles toward shore.

The bioluminescence that creates the glowing waves has made another rare appearance along Orange County’s coastline, and while it’s unknown how long it will stick around, the areas of thick red tide seen recently off of Newport Beach, Laguna Beach and San Clemente could indicate it may linger a while.

During the day, the photosynthetic organisms swim upward toward the light, creating a thin, dense layer near the surface. Then bioluminescent dinoflagellates, when disturbed by waves, a passing boat or even a sea creature, make the water look bright blue.

Not all red tide leads to glowing waves; a bloom last April that has some experts worried for sea birds was not the kind that lit up the night. The glowing kind of red tide has been seen sporadically from South Bay to San Diego the past few years, most times tough to track or staying just a few nights at a time.

Michael Latz, a bioluminescence expert at the Scripps Institution of Oceanography, said he noticed the red patches off San Clemente last week. He said it’s reasonable to think that this is tied to the massive bloom off the coast in 2020 that drove masses to the beach to get a glimpse of the electrified waves during the early days of the pandemic.

“There were probably lots of cysts that were produced then that form a seed bank for cells to later emerge into swimming cells,” he wrote in an e-mail.

That same Lingulodinium polyedra has been seen in San Diego at higher than normal abundance for a while, he noted.

Clarissa Anderson, executive director at the Southern California Coastal Ocean Observing System, said she just got an imaging report back from samples taken off the Newport Beach Pier. The species detected is Lingulodinium polyedra, the same that showed up in 2020 and possibly spawn from cysts still lingering – however it’s not unusual to have these blooms this time of year, she said.

The big rains with tropical storm Kay could have stimulated parts of this bloom and would potentially contribute to bacterial loads, Anderson said, though she added the duration of the hurricane-driven event was short and highly patchy.

Marine teams have been watching the red tide to see if local wildlife has been impacted in recent weeks. Some phytoplankton species can have harmful effects on birds and marine mammals.

National Oceanic Atmospheric Administration officials say they have been monitoring red tides to find ways to detect and forecast blooms with the goal of giving “communities advance warnings so they can adequately plan for and deal with the adverse environmental and health effects associated.”

While most people won’t have reactions if they swim or surf through a bloom, some people are sensitive to algal particles and the associated bacteria in the water, Anderson said.

Some people report itchy skin or trouble breathing. A red tide can also leave a funky smell on swimsuits or wetsuits.

The Office of Environmental Health Hazard Assessment asks anyone experiencing irritation or allergic reaction with water contact to take a survey so they can track and document cases.