- 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
- 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
- ``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
- ``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
- ``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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