State officials target invasive seaweed

Tariq Malik

HUNTINGTON BEACH -- State officials are aiming legislation at a

“killer” that has wound its way into the Seagate lagoons off Huntington

Harbour.

Assemblyman Tom Harman (R-Huntington Beach) has introduced a bill that

would ban the import, possession, sale or disposal of the saltwater

seaweed Caulerpa taxifolia, dubbed “killer algae” because of its invasive

manner of carpeting seabeds and driving out native vegetation and fish

nurseries.

“It’s very expensive to remove this algae and it must be done by

hand,” Harman said. “Luckily, seawater is pumped into these lagoons, and

it’s not directly connected to the ocean, where it’s fast growth rate

would make it an enormous threat to the ecology and entire Pacific

Coast.”

Caulerpa taxifolia is native to tropical waters and made its first

appearance in Southern California in the Agua Hedionda Lagoon in Carlsbad

last summer. This led to its discovery in local lagoons. Combat efforts

in Carlsbad began in October, marine officials said.

In the Mediterranean Sea, the invasive algae has spread for thousands

of miles along the sea bottom, ranging from the French Riviera to

Croatia.

Despite the colder temperatures of Huntington and Carlsbad ocean

waters, the plant’s growth has been phenomenal. It can grow up to 3

inches a day sprouting bright green fronds and blanketing its marine

environment.

Local sea life, like halibut and bass, find Caulerpa taxifolia noxious

because of its toxicity, and eelgrass and other protected ocean

vegetation are overtaken as the algae grows.

The cause, said marine ecologist Susan Williams, is not an angry

Mother Nature, but ourselves.

“The only way this plant is introduced is through us,” said Williams,

who also directs the Bodega Marine Laboratory. “People dump their

seawater aquariums into the oceans, which probably seems humane for the

fish at first glance, but it’s not.”

The plant is largely used for decoration in reef tanks and it’s

becoming less and less available strictly due to the problems that have

arisen. Though it’s illegal to import the algae, it can be bought and

sold in pet shops.

“It’s certainly a problem that some people are not disposing of it

properly, but it’s amazing that these plants are even surviving in our

waters,” said Craig Morton, owner of an aquarium sales and service shop.

The plant is typically sold in bunches costing between $10 and $15,

and thrives in tropical climates, he added.

The state Regional Water Quality Control Board has set aside $700,000

to eradicate the tough algae, and called in Rachel Woodfield, a senior

biologist with the consulting firm Merkel & Associates Inc.

Woodfield and scuba divers place secure plastic tarps over algae

patches with sandbags, and use chlorine “pucks” to kill the plant. With

the ease at which it spreads, the going has been tough.

“It’s absolutely overwhelming, and nonnative to this area,” Woodfield

said, adding that as a biologist she’s passionate for the preservation of

natural plant and animal species. “Just when you think you have a patch

clear, there’s another outbreak. It’s a wily plant.”

Disposing of plant

Marine ecologists stress that the proper way to dispose of Caulerpa

taxifola is by either freezing, baking or microwaving it until the algae

is crispy and dumping it in a proper landfill. Aquarium enthusiasts

should NOT dump aquarium contents into any body of water, or dump the

algae down drains or toilets.