Harbor declared free of dangerous seaweed

The National Oceanic and Atmospheric Administration’s National Marine Fisheries Service and marine biologists will continue to survey Southern California bays and estuaries, including the Bolsa Chica wetlands, after determining that a carpet of nonnative seaweed has been eradicated from Huntington Harbour.

In 2000, the service found the invasive leafy seaweed, called Caulerpa taxifolia, in the harbor’s surrounding lagoons while conducting unrelated environmental work, marine biologist Rachel Woodfield said. It covered about seven or eight acres of the harbor.

“In Huntington Harbour there was an immediate response, and we were able to stop it before it spread too far,” said Woodfield, who works for Merkel & Associates Inc., a private consulting firm. “It did escape from its starting point, but it didn’t escape from the harbor into the ocean, so I’d say it was a big bullet we dodged.”

Merkel & Associates’ marine biologists have already completed surveying Anaheim Bay near the naval area, waters just offshore of Huntington Beach and the harbor, said marine biologist Robert Mooney.

Because the Bolsa Chica wetlands are one of the smaller sites to survey, Mooney does not know exactly when it will get looked at, but he said it would probably be before November.

The seaweed devastated marine life and tourist destinations in the Mediterranean Sea when there was no immediate effort to eradicate it.

After an unrelated outbreak of Caulerpa was found in Carlsbad, public and private organizations moved quickly to complete the $650,000 eradication in Huntington Harbour. The Santa Ana Regional Water Quality Control Board paid for the operation.

“We covered the Caulerpa with heavy black plastic tarps under which we put pellets of chlorine, like you would use in a pool,” she said. “The tarps would hold the chlorine in place to kill the Caulerpa, but it kept the chlorine from escaping into the harbor.”

November 2002 was the last time the fisheries service saw Caulerpa in the harbor, but officials continued surveying until December of 2005, when their mathematical calculations made it almost 100% certain the seaweed was no longer present. The California Department of Fish and Game made the final determination for its official declaration July 12.

Woodfield said the seaweed was probably dumped into the harbor by a fish aquarium owner.

The plant, which is native in tropical oceans, was cultivated in the 1980s into an “aquarium strain,” which is tolerant of cold water. Caulerpa was widely used in aquariums, but is now illegal to possess in California, Woodfield said.

It’s also illegal to dump anything ? be it plant, animal or otherwise ? into the harbor or ocean.

“I doubt if any of this is malicious or intentional,” Woodfield said. “It’s just a lot of people don’t realize” the consequences.

Caulerpa was also declared eradicated from a site in San Diego County last week.

Woodfield is conducting outreach programs in conjunction with the National Marine Fisheries Service to educate residents about Caulerpa and other marine life, as well as the dangers of dumping in water.

For more information or to schedule an outreach program, call (858) 560-5465 or visit www.sccat.net.hbi.20-seaweed-2-BPhotoInfo621T2N2R20060720j2mg6pncCredit: Courtesy of Rachel Woodfield Caption: (LA)Caulerpa, an invasive leafy seaweed eradicated from Huntington Harbour.