JENNIFER YUEN/Daily Bruin Senior Staff Strains of brown
algae, sargassum, originated from Japan and has been invading Santa
Monica Bay for the past 30 years. Another species of algae,
caulerpa taxifolia, has also cropped up in Southern California.
By Hemesh Patel
Daily Bruin Staff
It’s a green mean killing machine.
Seventeen years ago, a toxic strain of algae, caulerpa
taxifolia, began to invade the Mediterranean and now it has reached
the Southern California coast.
The killer algae that resulted in the elimination of reefs and
native wildlife in Europe was found last year in San Diego and more
recently as far north as Huntington Harbor.
Another strain of brown algae, sargassum mutica, originated from
Japan and has been invading Santa Monica Bay for the past 30
years.
UCLA scientists said it is always possible that this new strain
of green algae can spread north to the coast of Los Angeles
County.
“These types of algae are such a problem because they
reproduce vigorously by both sexual and asexual
reproduction,” said Peggy Fong, assistant professor in the
department of organismic biology, ecology and evolution.
Caulerpa is native to warmer and tropical water such as the
Caribbean.
Because many believed the green algae could not live in colder
waters, scientists were surprised to find the strain of
Mediterranean algae in Southern California.
“Everything I learned in the past indicated that it should
not survive in cold water, but it has,” Fong said.
“It’s really a great concern.”
Because caulerpa was a common aquarium plant, scientists believe
people may have dumped the toxic strain of algae while cleaning out
their fish tanks.
“The algae may have gone down and drained to the ocean,
adapting to live in cooler waters,” Fong said.
Scientists in the Mediterranean have estimated that caulerpa has
colonized thousands of acres on the sea floor.
In areas such as Hawaii, caulerpa does not pose as great a
threat because the water is cleaner, and has less nutrients to
allow a big growth to take place.
“We have many species of caulerpa in Hawaii, but they are
not as big as they are in the Mediterranean,” said Isabella
Abbott, professor of botany at the University of Hawai’i.
Abbot said the Hawaiian islands have about four different types
of killer algae which are not as damaging as they are in California
and the Mediterranean.
Scientists are urging those who find a sample of the grass-like
caulerpa not to panic and not to rip it out.
Caulerpa can not be simply torn out wherever it is found because
it can reproduce by fragmentation.
A piece that is torn off into two pieces can generate two new
plants because this type of green algae grows at its ends.
“Its starting to spread now and has the potential to cause
a lot of damage,” said Jayson Smith, a second-year graduate
student in marine ecology.
The algae has the potential to disrupt the entire food chain
because wildlife that depends on native algae to survive cannot eat
the poisonous caulerpa, Fong said.
Efforts to eliminate this potentially devastating strain of
killer algae include staking down tarps on the ocean floor on top
of affected areas.
This technique blocks sunlight and kills off the algae on the
ocean floor because it will not be able to photosynthesize and
continue to grow.
Caulerpa is not the only type of killer algae attempting to
colonize the Southern California coast.
The second strain of killer algae reached Los Angeles County,
including Santa Monica Bay three decades ago and has continued to
grow.
But according to Fong, sargassum has not yet proven to be as
great a threat as caulerpa because it does not divide in the same
manner as the green strain.
It was first found in the north near San Francisco and has
spread down south, displacing the native species of sargassum in
California.
Ecologists believe it was transported through Japanese oysters
to France and then to other parts of the world through the hulls of
traveling ships.
“There’s not a lot of hope for sargassum, it’s
here to stay,” Fong said.
TWO MAIN TYPES OF KILLER ALGAE IN SOUTHERN
CALIFORNIA Name Caulerpa taxifolia
Sargassum muticum  Origin Caribbean Japan
 Common means of propagation Asexual
reproduction Sexual reproduction  When first found in
Southern CA One year ago 25-30 years ago Â
Regions of growth in California From San Diego to
Huntington Harbor From San Francisco to Santa Monica Bay Â
Rates of growth in other areas 50km over eight
years in Hawaii 30km a year in English coast Â
Habitat Attached to ocean floor Free floating
 How it is believed to have been introduced
Algae from fish tank dumped into the ocean Introduction of oysters
from Japan to France spores may have been transported on ship’s
hulls  Source: Joint Nature Conversation Committee(United
Kingdom) and California Water Quality Control Board Original
graphic by MAGGIE WOO/Daily Bruin Web adaptation by TODD
SHINTANI