Clamping down on quagga mussels

Local water authorities have begun closing some of the state’s prime fishing lakes in an effort to keep an infestation of tiny quagga mussels from fouling drinking water supplies for nearly 375,000 residents and threatening fish populations.

The closure two weeks ago of Lake Casitas, a favorite of bass anglers, to recreational boat use was followed within days by similar action at Westlake Lake in eastern Ventura County. Escondido imposed a temporary ban on private vessels at Lake Wolford, and Santa Barbara County officials are considering closing Lake Cachuma for at least six months.

Managers of local waterways say they’ve been forced to take drastic steps because the state Fish and Game Department has dragged its feet in dealing with what they say is the critical threat the nonnative mussels pose to vast supplies of drinking water.

Fish and Game has declined to ban recreational boat use at nearly a dozen locations where the pinkie-sized mollusk has been found, including in the Colorado River Aqueduct, Lake Havasu, two lakes in Riverside County and five reservoirs in San Diego County, water officials say.

“They are leaving open the infected waters, and we have to close our clean lakes to protect ourselves,” said Russ Baggerly, a member of a Ventura County water board that voted March 4 to close Lake Casitas to outside fishing boats for at least a year. “We have put the pressure on.”

Fish and Game’s acting director, John McCamman, believes that outright bans are an overzealous response, Terry Foreman, program manager for the department’s fisheries branch, told Santa Barbara County supervisors last week.

“Closures are a last resort,” Foreman said. “The director has made that clear.”

Native to Russia and Ukraine, the mussel migrated to the Great Lakes region in the 1980s, probably in the ballast of ocean freighters. They hitchhike on boats and trailers, and quickly form new colonies in bodies of water. They are virtually impossible to eradicate, potentially adding hundreds of millions of dollars in maintenance costs to pumps, pipes and other infrastructure across the state, water district officials say.

“The state has the authority to impose many more measures than they have done so far,” said Kate Rees, general manager of a Santa Barbara County water agency that draws from scenic Lake Cachuma to supply water to about 300,000 customers from Goleta to Carpinteria.

Local managers say they aren’t opposed to lakes being used for recreation and that temporary closures will give them time to come up with effective strategies to combat an invasion. Fishing from shore is still permitted, as well as boat fishing from vessels that have been dry-docked.

Other lake managers have responded by tightening boat inspections, requiring hot-water washes and placing suspect vessels in quarantine for several days. The mussel cannot survive more than a few days without water or at temperatures above 100 degrees Fahrenheit, according to biologists.

At Lake Castaic, anglers are given information about the quagga threat and boats are carefully inspected before they are allowed to launch, said Joyce Fitzpatrick, a spokeswoman for the Los Angeles County parks department. She added that Castaic’s managers were not considering a ban on recreational boats.

“Everyone is very aware of the issue, and we are doing as much as we can from a preventive level,” Fitzpatrick said.

Fish and Game officials, meanwhile, maintain that the local agencies’ alarm is misplaced. A state task force that includes officials from Fish and Game and the departments of Boating, Waterways and Water Resources is fine-tuning a coordinated attack on the quagga and its close cousin, the zebra mussel, said Susan Ellis, an invasive-species program manager.

Dive teams have been regularly inspecting water bodies in Southern California, including those along the State Water Project. So far, no mussels have been detected, Ellis said. Border checks have increased to catch vessels coming from infected waters at Lake Mead, east of Las Vegas. A canine patrol also has been trained to sniff out quaggas on boats, she said.

Foreman and other Fish and Game officials say these and other measures should be given a chance before closing off recreational fishing. And for now, it appears that the mussel’s migration has not reached beyond waterways fed by the Colorado River in Riverside and San Diego counties.

“The risk is low that mussels found in those water bodies would come north,” Ellis said.

In January, Fish and Game confirmed the presence of zebra mussels in San Justo Reservoir in San Benito, the first population of the striped mollusks found in California waters. Checks of nearby reservoirs turned up no trace of the pests, officials said.

Heads of local water districts say they don’t want to take any chances with the quagga, which has proved a formidable pest that can wreak havoc on water filtration systems and alter a lake’s ecology.

Rees of Lake Cachuma said the mussels cause an estimated $100 million a year in damage in the eastern United States and Canada, and the Metropolitan Water District has spent about $10 million on control measures.

In addition to damaging waterworks, the mussels disrupt the food chain by absorbing nutrients used by other species, including steelhead trout and bass, Rees said. They consume so much plant life that the water turns clear, allowing sunlight to stimulate the growth of a blue-green algae that can cause taste and odor problems in drinking water, she said. A healthy female can produce as many as 1 million larvae per year.

Rees and others fear that if the mussels are not kept out of local waterways, water customers will end up footing the cost of filtration and cleaning operations. If Lake Cachuma becomes infected, officials estimate it could cost hundreds of thousands of dollars each year in damage.

“My water district customers are not going to feel good about paying for something that is introduced by recreational activities over which they have no control,” Charles Hamilton, general manager of the Carpinteria Valley Water District, told Santa Barbara County officials.

Fishing enthusiasts packed the March 4 hearing to protest the ban on outside boats at Lake Casitas. Anglers say they are aware of the mussel problem and have cooperated with state and local officials to prevent them from entering new waters.

Even temporary closures could have large effects on the local economy as bass fishing tournaments dry up, they argued. Casitas officials estimated that the closure would cost the water district about $600,000 in lost revenue and hurt local businesses.

“You can take reasonable measures to prevent the spread of these invasive species,” said Tom Raftican, president of the United Anglers of Southern California. “Let’s certainly explore that before we simply close the lakes.”

The board’s action has been so divisive that frustrated anglers are threatening a recall of the three board members who voted in favor of it.

Baggerly said he had no apologies about the closures.

“If they brought the mussel to the lake, the fishery that they love would die,” he said. “They need a clear understanding of what is being saved and what’s being lost.”

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catherine.saillant@latimes.com