Water Pest Devilish as Mad Cow

The weed grows three inches a day and can blanket the bottom of a lagoon like some horrible shag carpet, killing crabs, lobsters and clams by stealing their sea floor and poisoning the water they live in.

So far, there’s only one known spot where Caulerpa taxifolia, a species of algae, is growing in Orange County: the lagoons of a Huntington Beach condominium community near the Anaheim Bay National Wildlife Refuge. But in the roughly six months since scuba divers discovered it there, the success of the battle against it has been uncertain at best.

“It is hard to quantify how much of the lagoon is contaminated with Caulerpa, but if there’s just a little bit, you can say the whole lagoon is contaminated,” said Susan Williams, director of the Bodega Marine Laboratory at UC Davis.

Williams, along with Assemblyman Tom Harman (R-Huntington Beach) spoke at a press conference Friday morning alongside the roughly six-acre lagoon. Harman is the principal sponsor of a bill to prohibit dumping the organism into any body of water, and to ban purchase, sale or importation of it.

They--and environmentalists--are trying to broaden concern about the species, which is used in saltwater fish tanks and looks like a fern. Williams said it is as serious a threat as mad cow disease, because while it is not toxic to humans, it is capable of clogging entire shipping ports.

“We have to nip the spread of this in the bud,” Harman said.

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Williams said the weed never should be thrown in the water. People also “shouldn’t flush it down the sink, or the toilet. They should microwave it, or bake it to a crisp,” before throwing it away with household garbage, she said.

Experts say the contamination in the lagoon can be traced to one sandwich-sized patch of the weed somebody threw in there. Relieved scientists say it hasn’t yet spread.

Biologists are battling the organism in Huntington Beach by sealing off the lagoon from Huntington Harbour with an underwater fence. Scuba divers scour the bottom of the lagoon regularly for patches, then cover them with a black tarp and inject chlorine into the underwater tent. Scientists say the chlorine kills everything underneath. But the divers have to be surgically precise; one small three-inch frond, or even one small piece of a frond, can escape and create another patch to contend with.

Concern first arose in the U.S. last year when the plant was discovered in a 350-acre lagoon in Carlsbad. It was the first time it had been found growing wild anywhere in North America. The discovery came during routine monitoring of a program to grow eel grass--which provides food for California halibut, sand bass, perch and lobster--in the lagoon there.

Rachel Woodfield, a marine biologist with Merkel & Associates Inc. in San Diego, is directing the Huntington Beach fight. Woodfield is credited with discovering the weed in Carlsbad. She said it took days to figure out what the plant was: It didn’t appear in any of the highbrow biology books or encyclopedias she checked. Eventually she found it in an amateur nature guide.

She remembers looking it up on the Internet and the picture slowly coming up on her computer screen. “I said, ‘My stars. We are in trouble.’ ”

Because the plant grows so rapidly--much like kudzu, which has conquered hills and meadows in the southern U.S.--it could be a massive threat to ecosystems, experts said. It has caused major damage to fisheries and tourist economies in Australia and the Mediterranean.