Red Tide Illuminating : Disgust, Delight Color Response to Phenomenon

Two Orange County surfers wandered into the red tide this week and had very different reactions.

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Bill Gregory, taking to the waves in San Clemente at night, entered what he described as a magical world of glittering bioluminescence.

“It was really beautiful,” he said. “It looked like stardust. When the water splashed, it sparkled.”

Gordon LaBedz, on the other hand, surfed Huntington Beach by day and had the opposite reaction.

“It was putrid,” said LaBedz, a family physician. “This is as bad as it gets. I walked in about knee-deep, then turned around and went back home.”

Ironically, both were responding to the same thing: the largest and longest-lasting phytoplankton bloom to hit Southern California in years. At night it is providing spectacular light shows to excited spectators gathered along the coast from Santa Barbara to San Diego. But during the day, the same natural phenomenon is turning the ocean the color of iced tea, striking fear and disgust in the hearts of some of the area’s most stoic beach-goers.

“It’s really impressive,” said Julie Smith, a marine biologist at the Orange County Marine Institute in Dana Point. “The bioluminescence has just been incredible.”

But would she swim in a red tide? “Not really,” Smith said. “It just doesn’t look very appealing.”

State health officials say the threat is mostly psychological.

Caused by the massive buildup of one- or two-cell floating plants--called phytoplankton--in the water, red tides generally occur in the spring or summer months but can occur any time. This one, experts say, was probably precipitated by the runoff of various soil nutrients into the ocean after the major storms earlier this year.

“Usually, the blooms are brief and patchy,” said Greg Langlois, a senior public health biologist with the state Department of Health Services, which has been monitoring red tides for the past three years. “But that is exactly the opposite of what’s been happening in Southern California.”

Although no official red-tide records exist, Langlois said, this one--first noticed in late January--is the thickest and longest-lasting red tide anyone can remember in at least 10 years.

“It’s an unusual event,” said David Parker, a senior biologist with the California Department of Fish and Game. “I can remember some that were intense, but none that encompassed this large a geographic area.”

Scientists attribute the characteristic brownish-red tinge--giving the tide its name--to the color of the millions of single plant cells per liter of water. The nighttime luminescence, they say, probably results from a chemical reaction in each cell giving off a minute amount of light that, when multiplied by the millions, becomes visible to the naked eye.

While California has a long history of shellfish poisoning associated with red tides, Langlois said, the current condition is the result of a common organism--called Gonyaulax polyedra --not known to be toxic. The microscopic plant is believed to have caused large fish kills in certain areas by using up the oxygen required by the fish, he said, but the only confirmed reports of harm to humans in past years have involved minor eye irritations experienced by some surfers and swimmers.

Dr. Hildy Meyers, medical director of communicable disease control and epidemiology at the Orange County Health Care Agency, said that there have been no reports of health problems associated with the current red tide.

Yet the folklore and fear persist.

Dennis Kelly, a professor of marine biology at Orange Coast College, recalls having diarrhea and flu-like symptoms after surfing in red tides 20 years ago. As a result, Kelly said, he won’t go swimming in them today.

And Smith, while admiring the biology involved in the phenomenon, said that she too prefers to enjoy the tide while dry. “It does look a little offensive,” she said of the muddy-looking water by daytime.

At night, however, landlubbers and ocean lovers alike find themselves drawn to the light shows. They gather at the beach to stare at breaking waves that look like fire, footprints in the sand that glow in the dark and fish that seem to leave ghostlike trails of light in the rolling surf.

Ken Plumb, out rowing with a friend near Seal Beach this week, saw what he described as “fireflies in the water” every time his oar broke the surface. “It was pretty incredible,” he said. “I’ve never seen anything like it.”

Becky Luth, who takes weekly ocean samples for the state Department of Health Services, returned from San Clemente to discover the net she had used still glowing. “It was beautiful,” she said. “It was spectacular.”

“It seems like a miracle,” added Ross Klingsberg, a biology instructor at the Orange County Marine Institute. “It’s almost magical. You feel kind of awe-struck. It restores your wonder at nature.”

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Why the Ocean Glows Single-celled organisms called dinoflagellates cast a red sheen on ocean water by day and a blue-green glow, called bioluminescence, by night. Bioluminescence occurs throughout nature when oxygen interacts with luciferin, a light-producing compound. How the process works in dinoflagellates: *

1. Water motion stimulates dinoflagellate’s cell wall 2. Ions flow into scintillon, making it acidic 3. Acidity causes luciferin to react with oxygen, causing light *

Red Tide Rising One liter of ocean water may contain up to 2 million dinoflagellates, a component of phytoplankton. The drifting masses of reddish phytoplankton--called a red tide and seen off Orange County’s coast--are blooming because of increased nutrients due to storm runoff and warm conditions. *

1. Rain washes nutrients into ocean 2. Storms churn ocean, bringing nutrient-rich water to surface 3. Calmer waters and intense sunshine promote phytoplankton growth *

Living Light Besides its eerie beauty, bioluminescence serves a purpose. Some illuminating facts: * Function: Startle predators, attract mates and prey * Nickname: Often called cold light because it produces no heat * Color: Multicolored or blue-green, which transmits best through seawater * Rhythm: Quick flashes or steady stream Sources: Orange County Marine Institute, Scripps Institution of Oceanography, World Book Encyclopedia; Researched by CAROLINE LEMKE / Los Angeles Times