Deadly Giant Cloned Algae
Arrives In California Waters
By Andrew Quinn
SAN FRANCISCO (Reuters) - It looks like a soft carpet of vibrant green, rippling in the ocean's currents. But biologists call it an alien invader, a killer that strangles native sea plants, plays havoc with fish populations and causes ecological devastation in coastal communities.
Having defeated the control efforts of France, Spain, Monaco and Italy to spread throughout the north Mediterranean, the Caulerpa taxifolia alga has been spotted for the first time in California waters -- prompting a red alert among environmentalists and oceanographers watching for new threats to the region's delicate ecology.
``In terms of potential damage, this species is a very, very serious problem,'' Robert Hoffman of the National Marine Fisheries Service said on Thursday. ``It moves in and displaces anything that is normally found along the ocean bottom and becomes the one single species that dominates the habitat.''
Marine biologists identified the first North American sample of the species several weeks ago in eelgrass beds in a coastal lagoon about 20 miles (32 km) north of San Diego.
Scientists say the lagoon infestation is an isolated case and stress there is no indication so far that the algae have spread into open ocean along the coast.
But many marine biologists fear it is only a matter of time before the hardy water plants -- originally engineered to look pretty in home aquariums -- take hold in coastal waters, where they could imperil the eelgrass and kelp beds that form the basis of the region's marine ecosystem.
``Once it gets out of control, it is really out of control,'' Hoffman said. ``That's why we are moving as fast as we can.''
A Deadly Clone Escapes In Monaco
For an object lesson in what can happen when the algae get a head start, scientists point to the northern Mediterranean.
Caulerpa taxifolia originally gained notice as a fast-growing plant used to decorate saltwater aquariums. A hardier, cloned version of the species was developed for display at the Stuttgart Aquarium in Germany in the early 1980s and was provided to aquariums in France and Monaco to brighten up their displays.
Around 1984, however, a sample apparently escaped from the Oceanographic Museum of Monaco into the open Mediterranean. From an initial patch of about 1.2 square yards (one square meter), the algae spread to cover about 2.5 acres (one hectare) of ocean by 1989.
Today, caulerpa algae have spread throughout the northern Mediterranean, harming tourism, destroying recreational diving, overgrowing native sea plants, influencing fish populations and tangling net fishing operations.
The original caulerpa may have seemed a fragile and decorative plant, but the European clone has proved a resourceful foe -- growing to nearly 10 feet (three meters) in length, thriving in deeper and colder water, and able to survive for up to 10 days out of water.
While harmless to humans, the algae contain a toxin that can interfere with the eggs of some marine mammals and kill off many microscopic organisms.
``Carpet Of Astroturf''
Scientists have compared the introduction of the algae to ''unrolling a carpet of Astroturf'' across the sea bottom, where it soaks up all available nutrients and bulldozes other species out of existence.
Hoffman of the National Marine Fisheries Service said the California infestation probably occurred when somebody dumped a fish tank into a storm drain. Steps are under way to kill off the invader, covering the algal turf with tarpaulins and then dosing it with herbicides, he said.
Andrew Cohen, a marine biologist at the San Francisco Estuary Institute who pioneered a successful drive to get the United States to ban the import of caulerpa as a ``noxious weed'' in 1999, said the San Diego discovery did not necessarily mean the end of California's native coastal ecosystem.
``We are in as good a shape as we could be to eradicate this initial introduction,'' Cohen said. But he said the menace illustrated the vulnerability of the world's interconnected ecosystems, where a common fish tank could hold the key to the destruction of huge expanses of open ocean.
``We need more education on these kind of threats,'' he said. ``The chances are pretty good there is more of this clone out there in aquariums or supply stores around the country.''

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