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Sea foam: More than just my personal bubble bath_Sydney's Ocean Log

Sydney the Golden Seal and water wonder dogI’m Sydney, the “Golden Seal” retriever-husky, back this week to discuss the art of bathing, a topic of interest to dogs and those dog tired from a long day at work. Should you turn up your snout at the idea of a saltwater dip because only a bubble bath will do, unleash your dogma, and hightail over to the mega bathtub on the coast. I guarantee you’ll be panting over the patched and streaked white stuff floating on the surface or as Don Ho would sing, “Tiny bubbles in the water...” Science types call it sea foam. High tech, huh?

I call this a seafoam island.  ©2002 Judith Lea GarfieldFoam forms when a wave builds and then collapses into the ocean, whipping up zillions of bubbles that stick together. Within seconds, these bubbles burst but are replaced right away by fresh foam created from the next plunging wave. Winds also dissolve sea foam by blowing off the tops. All year round I see thin, frothy masses floating on the surface just beyond the waves. But, you bubble bath aficionados whine, this wimpy foam has no staying power, and you want to luxuriate under suds that stick around. Not to worry. I have just the spume for you.

Sea foam can be whisked up thick and high like stiffened egg whites atop a lemon pie. The secret ingredient in this meringue is alginic acid, a complex sugar substance that leaks out when kelp strands break or decay. It coats the bubbles and keeps them in good form. Alginic acid looks clear and feels like slippery mucus. If I bite off a piece of kelp, in no time drippy goop oozes everywhere. No, it’s not my drool. In fact, this viscous slime is added to stabilize and thicken your salad dressing, ice cream, and beer (apparently dogs aren’t the only ones who eat gross stuff).

During summer when the ocean water temperature inches toward 70 degrees, the overheated kelp starts decomposing, which frees up lots of sticky mucus. Since small summer waves don’t have enough churning power to send the foam out to sea or toward the beach, the suds languish in position for weeks. I often find myself wading through thick, yellowish foam that collects and stagnates just outside the mouth of the Cove. With satisfaction I emerge wearing an unladylike beard below my lips. This is way better than all the Mr. Bubble in a tub. That’s summer foam for you.

When winter's stormy sea, high tide, and wind link arms, seafoam can swamp the boardwalk, creating a singularly SoCal snowfall scenic. ©2002 Judith Lea GarfieldWinter foam, on the other paw, evolves ferociously. Aggressive onshore winds and epic waves tear up loads of kelp strands anchored offshore to result in a frenzy of foam that blows to shore. Some years, the barmy barrage is so bountiful that it blankets the beach and boardwalk at La Jolla Shores, creating a fantasy snowfall (sudsfall?) scene Billowing bubbles of seafoamthat delights the frisky husky part of me.

But sea foam isn’t just for fun. It’s a true ecological habitat. Trapped within the bubbles is a stew of decomposing and dead matter, along with microorganisms that grow wild in the high-sugar environment. Currents carry these booming communities across distances where passers-by may take up residence and where interlopers snack on the concentrated gumbo skimming by overhead. Although only a bit of the entire ocean surface is covered by foam at any given time, because there is so much ocean, foam real estate is huge. This means that sea foam may be important for spreading life and introducing exotic cuisine to different parts of the marine community. Whatever. It’s still my personal bubble bath.

(Write Sydney using the Contact page, and put Sydney the Golden Seal in the Subject line.)


— Judith Lea Garfield, naturalist and underwater photographer, has authored two natural history books about the underwater park off La Jolla Cove and La Jolla Shores. Send comments to