An invasive mussel first detected in California less than a year ago has surged across the state's southern counties, stirring concern that its spread will inflict costly damage to public water systems and fisheries statewide.
The infamous fresh-water quagga mussel, which has wreaked havoc in the Great Lakes, multiplies so quickly and prolifically that it forms large masses that can clog water pumps, pipelines, power plant intakes and farm irrigation lines.
Its rapid-fire invasion this year from Lake Mead -- which straddles the border between Arizona and Nevada -- southwest to San Diego is alarming water officials in a semi-arid region that heavily depends on imported water moved through a vast network of pipelines and canals.
The quagga already has infested the 242-mile-long California Aqueduct, five San Diego County reservoirs and two of the three largest reservoirs in Riverside County operated by the Metropolitan Water District, which supplies Los Angeles with most of its water.
The mussel's microscopic larvae can swiftly and invisibly move through waterways and the pest is typically found only after it has implanted itself. There is no known method to eradicate the thumbnail sized mussel, but at least one agency is attempting chlorination in the hopes of killing larvae.
Although the quagga does not make water unsafe to drink, officials are concerned that it could infiltrate the State Water Project that delivers water from Northern California to Southern California as well as expansive irrigation systems that feed the state's agricultural industry.
"All of that is subject to disruption by quagga," said Edwin D. Grosholz, an expert on invasive mussels and Cooperative Extension specialist at UC Davis. "There's nothing at all to limit their spread north to Northern California."
He and some other scientists believe that government agencies should be more aggressive in fending off the mussel, especially because of the economic and environmental impacts it could have in Western states.
Water operators are bracing for increased costs.
"If you've got 100,000 of these things clogging up an intake grate, pumps, valves, then you have the time and expense of going in and cleaning it up," said John Liarakos, spokesman for the San Diego County Water Authority.
"It means we will inevitably suffer through higher operation and maintenance costs," said Jim Barrett, director of public utilities in San Diego, where divers must now inspect city reservoirs for mussels.
