That Foam on the Beach Is (Probably) Fine
As I traipsed barefoot along Ocean Beach’s chilly February sand, ankle-high clumps of spume trembled in the breeze along the tideline, drawing me toward the surf. Upon closer inspection, the mounds of froth revealed millions of bubbles, each one’s surface transforming the gloomy gray daylight into a glistening kaleidoscope of greens, pinks, blues, and golds.
I crouched down and stared at the twirling colors, mesmerized. Then the largest of the bubbles burst, and I became entranced by the ephemeral drama of the foam’s demise. Larger bubbles popped first, and soon only the smallest remained, fizzling away in their rainbow riot until the entire phenomenon (and my feet) were engulfed by an incoming wave.
Particularly in winter and early spring, strong winds and churning waves whip up ocean surf like seawater latte foam, making sudsy blobs a more common sight on the California coast. Many beachgoers may find gobs of foam concerning, especially if they’re red or brown instead of white, or smell like decay. While some sea foam contains pollution or toxins from harmful algae blooms (also known as red tides), most of it is harmless to humans and their companions.
“It’s really not dangerous,” says Raphael Kudela, a UC Santa Cruz ocean sciences professor who specializes in phytoplankton. “If you touch it, or you’re swimming in it, or when your dog runs through it, if you just wash it off, it’s fine.”