Invading Species Hit State and Nation Hard

California waters are being quietly invaded by exotic species from around the world, arriving by freighters dumping ballast water, pet owners emptying aquariums down storm drains and fishermen tossing unused bait.

Although largely unnoticed by the public, worried scientists and federal officials say that if allowed to spread unchecked, the species could cripple marine ecosystems, and harm commercial fisheries and tourism.

Off Huntington Beach and Carlsbad, biologists are struggling to eradicate Caulerpa taxifolia, or “killer algae,” a bright green Caribbean seaweed that has already caused extensive and costly damage to the Mediterranean Sea coast. Eradication here will probably cost state taxpayers $2 million.

In the Santa Monica Mountains, more than a third of all streams, including heavily polluted Malibu Creek, are now home to red-swamp crayfish from Louisiana and Alabama, harming fast-disappearing native tree frogs, newts and salamanders.

Much of the damage is subtle but pervasive. The common mussels seen clinging to docks and pilings from San Diego to Santa Barbara originate in the Mediterranean; native mussels have been crowded out.

Possibly the hardest hit spot on the California coast is San Francisco Bay, which scientists call “the most invaded estuary in the world.”

There are about 250 known exotic species in the bay, and potentially hundreds more. Many native species are all but gone.

Chinook salmon, delta smelt and steelhead trout, already endangered native fish, are being preyed on by striped bass, an East Coast fish probably introduced by sport fishermen. Native mollusks are being starved out by Asian clams.

Experts say that combined with fast-encroaching nonnative species on land, the problem is enormous.

“There’s no doubt about it,” said Lee Kats, a Pepperdine University professor. “Exotic species will be the primary environmental and ecological concern of this century.”

U.S. Fish and Wildlife Service spokesman Ken Burton agreed: “This may be the No. 1 environmental threat facing us right now.”

He and others said the scale of the problem is becoming increasingly evident as researchers document the widespread introduction of alien species to regions that have been biologically isolated for millenniums.

There are seven underwater “islands” of biodiversity that hug the world’s continents, including one that stretches from Alaska along California to Baja California. Separated by deep seas, each of these bioregions is vastly different from the others.

Similar creatures separated by geography and evolutionary time long ago morphed into distinct species, said Andrew Cohen of the San Francisco Estuary Institute, who is one of the nation’s leading experts on aquatic alien species.

Cohen said global commerce and travel are “essentially combining these isolated bioregions, and mixing them all up into one big bioregion” that cannot support so many species.

When Cohen sticks his hand underneath a dock in San Francisco Bay and pulls out a handful of muck, he can peer through a magnifying glass and identify blue bay mussels from the Mediterranean, tube-building worms from the Indo-Pacific, hydroids from Japan and sea squirts from the Atlantic.

The National Bill Is $138 Billion a Year

Exotic species on land and in the water already cost the United States $138 billion annually, according to the U.S. Fish and Wildlife Service. The U.S. Geological Survey estimates that $5 billion will be spent in the Great Lakes region alone next year fighting the infamous zebra mussel, brought over from Eastern Europe on freighter ships. Marine invaders also have been tied to some human disease outbreaks. Nationwide, they are the No. 2 threat to endangered species, behind habitat loss, federal wildlife officials say.

Exotic species can take over in new waters for two reasons: Their natural predators are not present, and native species haven’t evolved with the ability to hide from them, compete or fight back.

For more than a decade, Kats and his students have studied streams in the Santa Monica Mountains, where crayfish from the American South are popular fishing bait. But turned loose, they feed on fast-disappearing native tree frogs, newts and salamanders. Natural enemies of the crayfish in the South are not present here, allowing them to nimbly devour local stream life.

“They’re voracious predators. They eat anything they can get their jaws on,” Kats said. “I could take you to spectacularly beautiful streams that are only one bait bucket away from being changed permanently.”

The biggest potential threat is unfolding off Orange and San Diego counties, the only place so far in the United States where Caulerpa taxifolia--”killer algae”--has been found. The seaweed is popular in saltwater aquariums because of its brilliant green foliage.

While not harmful to people, it essentially smothers eelgrass meadows and other plants crucial to the marine food web, endangering many fish and invertebrate species. The algae can grow up to 9 feet long, with up to 200 fronds, making it one of the largest single-cell organisms in the world. It can survive 10 days out of the water, and leaving even one millimeter behind can cause another outbreak.

In the Mediterranean, the lush plant has caused massive damage to ecosystems, fisheries and tourist economy. Once popular scuba diving waters are clogged with thick algae forests. Commercial fishing and boating have been cut off in formerly productive harbors.

There is disagreement on how the first piece of Caulerpa, native to the Caribbean, escaped from the Oceanographic Museum of Monaco in 1984. But there is no doubt about what has happened since. Some say the aquarium discarded old tank water; others think a frond fell out a window. Still others think it was intentionally introduced into the Mediterranean Sea by researchers. Whatever the cause, a square meter was found in the water under the museum’s windows in 1984. From there, it ran rampant.

Caulerpa spreads through fragmentation--if a small piece breaks off, it quickly establishes a new colony. Sixteen years later, the killer algae now carpets 10,000 acres of ocean floor off Spain, France, Italy and Croatia, all offshoots of that original patch.

“It grows in this turf-like mode,” said Bob Hoffman of the National Marine Fisheries Service. “It totally covers the bottom. The algae forms oxygen-depleted areas that nothing can live in.”

Seagrass reefs, soft-bottom and rocky sea floor habitats have all been wiped out.

Experts believe the specimens of Caulerpa in a San Diego County pond and a Huntington Harbor lagoon came from individual aquarium owners who emptied their tanks’ contents down storm drains.

Both outbreaks were quickly treated with chlorine. But when scientists forgot to close a storm drain in the Huntington Beach lagoon, a small amount escaped into much larger Huntington Harbor. They fear it will spread into the open Pacific, via boat propellers, anchors and fishing equipment.

Though the algae’s importation to the United States was banned last year, it is still present in countless private aquariums, and readily available over the Internet, said Denny Lassuy, a U.S. Fish and Wildlife Service biologist.

The majority of the marine invaders along California’s coast are released by vessels arriving from overseas markets. California docks the most overseas ships in the nation, and the ports of Long Beach and Los Angeles comprise the third-largest harbor complex in the world.

Cargo-laden ships that arrive in other countries unload, then promptly fill up their empty hulls with local water to ensure smooth sailing on the return voyage. This ballast water is dumped near U.S. shores.

Researchers estimate that one gallon of ballast water contains an average of 31 billion suspected viruses and 3.5 billion bacteria. About 87 million tons of foreign ballast water is released into American ports annually, according to a recent study by the Smithsonian Environmental Research Center of Edgewater, Md.

In 1998, 419 people in Texas who ate raw Galveston Bay oysters became gut-wrenchingly ill. Health officials suspect the outbreak was caused by a ship that released ballast water containing a virus common in Southeast Asian waters. Four years earlier, cholera found in oysters in Alabama’s Mobile Bay was traced to a deadly outbreak in Peru. While no one died in the United States, more than 10,000 Peruvians did, and 1 million people became ill. Scientists speculate that the waterborne disease was carried to Peru in Southeast Asian ballast water.

Ships headed to Washington state, California and the Great Lakes are now required to release ballast water far offshore. But compliance and enforcement are spotty, according to an October study by the National Ballast Information Clearinghouse. In the rest of the nation, guidelines are voluntary.

Mitten Crabs Invade River

Another common invader is the Chinese mitten crab.

Authorities suspect someone attempted to start a mitten crab fishery in San Francisco Bay, or the crabs were introduced through ballast water from China or South Korea. A pair of females sells for $30 in Hong Kong, where their orange roe-filled ovaries are considered a delicacy.

Because they breed in saltwater, but live in freshwater, the hairy half-foot crabs swim out of the bay into the San Joaquin River. In 1996, four crabs were caught in grates at a federal drinking water plant in Tracy; by 1998, 20,000 crabs were caught every day, hampering the rescue of endangered Delta smelt and other trapped fish.

Workers were so overwhelmed that they filled six-foot trenches with the crabs, and smashed them with backhoes. After animal rights activists complained, officials began selling them to a fertilizer plant.

A group of scientists surveyed Southland waters this summer for the first broad study of marine exotics in the region. Results are expected this spring.

Experts say that until there are cohesive state and national policies to prevent alien species from entering American waters, the environmental and economic toll is inevitable.

In 1998, Cohen and 105 scientists urged the departments of interior and commerce to change the country’s import policy. Federal regulators use a “dirty list” of banned flora and fauna. Anything not on the list can enter. Scientists advocated changing to a “clean list.” If an export is not on the list, the person who wants to bring it in must prove that it is not a threat to native ecosystems.

Officials have tried to bolster lax policies about importing flora and fauna, but often have been shot down by the strong lobbying of the aquaculture and ornamental plant industries.

Environmentalists like Linda Sheehan of the Center for Marine Conservation are pushing for a federal law that would mandate mid-sea ballast water exchange.

Federal officials are beginning to pay attention. President Clinton signed a 1999 executive order directing federal agencies to expand efforts to fight alien species “that are upsetting nature’s balance, squeezing out our native species, causing severe economic damage and transforming our landscape.”

Last month, Fish and Wildlife officials launched an education campaign warning the public about exotic flora and fauna, dubbed: “America’s Least Wanted.”

Rachel Woodfield, a San Diego marine biologist battling killer algae in Huntington Beach, says public education is crucial. She points with frustration to a Sri Lankan eel--probably a castoff pet--found swimming near the algae last month.

“I’m out there knocking myself out, and someone goes and dumps an eel into” a storm drain, she said.

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Alien Invaders

California’s offshore waters lie in one of the world’s seven marine bioregions. The regions hug continents and are separated by deep seas. Though similar creatures are found in many of the bioregions, the species evolved differently because of their separation. But now, with increased international trade, species that spent milleniums apart are meeting, with often devastating results.

Chinese mitten crab burrows into riverbanks, gets trapped in drinking water supply. Is hazardous to water engineering projects.

Mediteranean “killer algae,” a prolific, invading species. A danger to underwater ecosystems

Zebra mussel originated in Eastern Europe. Clogs water intake pipes, causing billions of dollars in damage.

Exotic species -- Scientists estimate that the San Francisco estuary now has more than 250 species that were not present 400 years ago. The sharpest increase has been in the last three decades.

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Sources: Science Magazine, San Francisco Estuary Institute