Algae invaders

Divers at China Cove in Newport Beach, Calif., began sucking up the seafloor July 7 in an attempt to prevent an invasive species from taking hold. Using a massive black hose attached to a pump, state and local environmental officials are hoping to stop the spread of an invasive algae species they believe could harm Southern California’s aquatic ecosystem.

The patch of bright green caulerpa prolifera algae isn’t big, measuring 1,000 square feet. But officials know it can easily spread. Algae in the caulerpa family typically reproduce asexually by spawning new organisms from bits that break off the original plant. Once the invasive and fast-growing algae take hold, they tend to choke out local species of algae that aquatic life depends on for food and cover.

“We’re at a point here where we’ve got a shot to get rid of it,” said Robert Mooney, a biologist with Marine Taxonomic Services who has overseen the algae’s removal. “We don’t have the luxury of waiting to see what happens.”

Scientists discovered the caulerpa prolifera off the coast of Newport Beach late last year and knew they had to act fast. Egyptian officials have battled the exotic invasive seaweed in parts of the Suez Canal for two decades without eliminating it. A popular choice for salt-water aquariums, caulerpa prolifera likely took root in California waters when an aquarium owner dumped his tank, a local scientist said.

“It’s more than likely the source is an aquarium release,” said Keith Merkel, a biologist consulting on the project. “It can spread from very small fragments if you replace water in your aquarium, cleaning gravels and using buckets to dip water out and in.”

In 2006, California officials declared victory over another invasive algae after a prolonged six-year, $7-million battle with caulerpa taxifolia. Dubbed “killer algae” at the time, the algae native to Florida and the Caribbean has become established across the Mediterranean Sea.

To avoid the Mediterranean’s fate, California officials will need to identify other patches of caulerpa algae, a task made more difficult by the propensity of the organism to reproduce as it breaks apart. “There’s a good chance that it has spread, we just don’t know where—which is the biggest fear that we have,” Merkel said.