Glowing phytoplankton light up the waves near Torrey Pines Beach on Tuesday.
Photo: Erik Jepsen/UC San Diego

Forget catching rays on the beach. If you’re near San Diego, do yourself a favor and go check out the surf at night.

A rare bioluminescent red tide has created ghostly scenes on the shores of Southern California, from La Jolla to Encinitas. The last one was five years ago and only lasted a week so the clock is ticking to catch the phenomenon.

The term red tide describes the scene by daylight, with a vast mat of reddish phytoplankton hanging out on the surface of the ocean. Turns out we humans play a little role in their color, too.

“Each cell contains a little bit of sunscreen that gives it color,” Michael Latz, a researcher at Scripps Institute of Oceanography, said in a statement. “On sunny days the organisms swim toward the surface, where they concentrate resulting in the intensified coloration.”

The sprawling blob includes dinoflagellates, including Ceratium falcatiforme, a species that Latz said has never been seen on the West Coast before. It’s this species and other dinoflagellates that create the real magic once the sun goes down, turning the red tide electric blue through a series of chemical reactions known as bioluminescence.

Advertisement

As the waves crash and stir up the dinoflagellates, they grow even more brightly, which is how you end up with waves that look like this:

“It kind of looked like the color of a light saber,” Stephen Bay, a local photographer, told CBS News. “It really was a bright blue color that was just fantastic to look at.”

Advertisement

Hard agree, Stephen.

In addition to geeking out over the wonders of the neon seas, staff at Scripps are sampling the waters for science. There’s still a lot of mystery surrounding red tides in the area, including exactly what causes them to wash ashore in the first place.

“We are so excited about the red tide,” Caitlin Scully, marketing manager at the Birch Aquarium managed by Scripps, told Earther in an email. “I went out to see it last night and it’s truly spectacular.”

Advertisement

There are a number of places where glowing waters are a regularly occurrence, including Puerto Rico’s famous biobays. Those bays tend to have dinoflagellates in great numbers on the regular, making the displays a tourist attraction.

What’s happening in San Diego is much more unusual, though. The last time the ocean lit up at night was September 2013. Researchers are unsure how long the latest electric tide will stick around, so take your night photos while the snapping’s good.

But if you do miss it, the Birch Aquarium (which is linked with Scripps) has a consolation prize in the form of an art installation called “Infinity Cube” that features walls and ceilings covered in video footage of glowing dinoflagellates.