In 2000 the strain was found in the coast of California (U.S.A.), near San Diego, and also in the coast of New South Wales, Australia. The California invasion was small enough to be considered controllable: it was covered with tarpaulin which was held down with sandbags at the edges of the infestation. Then chlorine was poured in through tubes which fed into certain openings in the tarpaulin: the interior of the tarpaulin fills up with chlorine and kills living organisms inside it, including the killer algae but also fish and plants. The killing of such other organisms was not desirable but was deemed preferable to letting the weed grow unchecked, which would in the end yield greater havoc on these same creatures.
The invasion in the Californian coast was most probably caused by an aquarium owner improperly dumping the contents, allowing C. taxifolia to flow through a storm sewer into the lagoon where the invasion was discovered. California has since passed a law forbidding the possession, sale or transport of Caulerpa taxifolia within the state. There is also a federal law under the Noxious Weed Act forbidding interstate sale and transport of the aquarium strain Caulerpa.
