The Sea’s Living Light Show : Chemical Reaction ‘Looks Like Little Fireflies in the Ocean’

Loud music mixed with animated voices wafted down the hill into Dana Point Harbor as the research vessel Sea Explorer pulled away from the dock.

It was a recent Saturday night, and patrons of the nightclub overlooking the cove were whooping it up.

Aboard the boat, however, a quieter sort of revelry was about to begin. Here, huddled on the deck in their coats and scarves, a different group stood poised to celebrate the weekend.

“I never knew that the ocean could glow,” Melissa Salisbury, a 19-year-old student from Laguna Niguel, said later. “It just lit up and sparkled.”

Welcome to the Orange County Marine Institute’s Saturday night bioluminescence cruise, a summer excursion into another kind of night life.

“Our goal is to expose people to the unusual and the bizarre,” Julie Goodson, the institute’s director of at-sea programs, said of the cruise, which she believes is the only one of its kind in the country.

“We want to get people excited about the ocean,” Goodson said. “There’s so much out there that most don’t know.”

One of the least known, she said, is bioluminescence.

Caused by a chemical reaction in cells of certain organisms, it is a subtle greenish or bluish glow that, when multiplied, becomes visible to the naked eye.

Beach-goers sometimes notice it in the surf during seasonal “red tide” conditions resulting from large blooms of phytoplankton--one- or two-cell floating plants in the water.

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What many don’t realize, though, is that the phenomenon also occurs regularly in such marine organisms as jellyfish, copepods, sea pansies, midshipman fish, tube worms and sea pens.

Believed to be a product of respiration in lower cells, the larger animals seem to have adapted the phenomenon to their own uses, including luring prey, communicating between species, distracting predators or attracting mates.

“Some animals have been able to encapsulate and use it to their own advantage,” said Harry Helling, the institute’s associate executive director, who introduced the phenomenon to the public five years ago in an exhibition of paintings and sculptures made with bioluminescent bacteria.

The show was so successful that he decided to try using the strange natural light shows as a means of teaching about the ocean’s larger ecosystem. “We found that people were fascinated and wanted to learn more,” Helling said.

For the past two summers, the institute has been piloting the program by offering the bioluminescence night cruises on a limited basis. Now, for the first time, Helling said, the experience--scheduled for 10 weekends this summer--has become one of the institute’s “premier” cruises, expected to be attended by at least 500 people at $18 a head.

“The cruise is designed to inspire a sense of awe in our visitors about the ocean,” the director said.

To get that awe going July 1, Sea Explorer crew members--each wearing a badge displaying a patch of glowing bacteria collected the day before--dragged a trawl and a smaller, finer-meshed plankton net behind the vessel during the 2 1/2-hour cruise off Dana Point Harbor.

In the meantime, the 46 passengers--including several children--divided their time between watching tiny organisms through the ship’s two microscopes and reaching into several touch tanks on deck to poke or prod various creatures left over from a previous cruise.

“This is rad!” Michele Pelnar, 16, of Laguna Hills exclaimed after gently stroking a sea pen, a feathery, pen-shaped creature that lives in the mud and lit up to her touch like a Fourth of July sparkler.

Newport beach resident Steve Santz, 44, had a similar reaction to the glow of the sea pansy, a purple, mushroom-shaped animal that sent pulses of greenish light across its body whenever touched. “I had no idea how much of a living thing the ocean is,” he said.

A few passengers experienced the pangs of seasickness. “My body interfered with my enjoyment,” said Helen Lorenzini of Long Beach.

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For most, though, the high point came when crew members pulled up the net full of plankton, the microscopic plant cells most closely associated with bioluminescence. As some gently stroked the fine mesh, others literally gasped at the sight of the glowing, ghostlike traces their fingers left on the net.

“It looks like little fireflies in the ocean,” Dave Nolan, 51, of Mission Viejo said with a big grin.

Which is precisely what makes it so charming, according to Helling.

“There’s something magical about animals giving off their own light,” he said. “It draws out the child in everybody.”

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Why the Ocean Glows

Single-celled organisms called dinoflagellates cast 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

Living Light

Besides its eerie beauty, bioluminescence serves a purpose. Some illuminating facts:

* Function: Startle predators, attract mates and prey

* 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