A renowned biologist said today the zebra mussels found in a
small reservoir south of Hollister may have been in the basin for
years and hitched a ride over the Rocky Mountains to get there.
Update:New box about the mussel at bottom of story
A renowned biologist said today the zebra mussels found in a small reservoir south of Hollister may have been in the basin for years and hitched a ride over the Rocky Mountains to get there.
Dr. Daniel P. Molloy also said a soil bacterium – which could be commercially available within two years – acts as a toxin and can kill 70 percent to 90 percent of the mollusk and its close cousin, the quagga mussel, when applied.
Molloy is director of Cambridge Field Research Laboratory at the New York State Museum and has researched the zebra mussel for nearly two decades.
State officials confirmed Monday the presence of zebra mussels in San Justo Reservoir – which is connected to California’s central waterways that feed millions of acres of farmland and provide drinking water. While it is unknown how widespread the pesky mollusks are, it is feared they could clog water pumps and pipes and alter ecosystems.
It’s unknown how the zebra mussels came to the reservoir, but a fisherman pulled a clump of the mussels from the reservoir on Jan. 5, the California Department of Fish and Game reported.
“And that clump didn’t fall off a boat,” Molloy said Wednesday. “Those are the generations after the first settlers came there.”
Officials from the U.S. Bureau of Reclamation – the agency that owns San Justo Reservoir – said Tuesday the zebra mussels found there are most likely 1 to 3 years old.
Molloy said he was surprised when state officials found the quagga before the zebra mussel in California.
“Zebra mussels in Europe spread much more quickly from their native range than quagga mussels have,” Molloy said.
The discovery in San Justo Reservoir marks not only the first in the state, Molloy said, but also west of Oklahoma. He credits the Rocky Mountains for blocking the progress of the freshwater mussels, first found in the Great Lakes area in the late 1980s. They have since spread downstream into the Mississippi River drainage.
Since the mussels were brought to American waters – most likely in the ballasts of ships from Europe – they have caused billions of dollars in damage to infrastructure and ecosystems.
Zebra and quagga mussels are native to the Caspian Sea and eventually spread throughout Europe, but the Ural Mountains saved Asia from an encroachment, Molloy said.
The mussels’ larvae float on water currents but can also be spread through recreational boating.
‘Don’t move a mussel,’ state officials ask
When state officials learned in January 2007 that quagga mussels were present in Lake Mead – a Nevada reservoir that feeds the Colorado River and ultimately California’s aqueduct system – they began intensive inspections of boats crossing the border into California.
Alexia Retallack, a spokeswoman for the California Department of Fish and Game, said the state has stopped approximately 80,000 boats before entering – requiring 7,000 of those to dry, drain and clean – and found mussels on 104 vessels in the past year.
“We ask boaters, please help us out,” Retallack said.
Retallack said zebra mussels can live out of water for five days and that state officials recommend leaving a boat dry and cleaned for at least that long.
A zebra mussel can spawn up to one million eggs in a year, Retallack said, making them “prolific breeders, voracious feeders.”
The mussels can also choke out indigenous aquatic life by filtering out the water’s food base.
San Justo Reservoir remained closed Wednesday and federal, state and local government officials will most likely discuss the zebra mussels via teleconference Thursday, San Benito County Water District Manager Lance Johnson said.
Johnson urged recreation area users to help state officials spot the mussels.
“More people really need to be cognizant of these things and keep and eye out for them, because it’s a problem all across the state,” Johnson said.
For now, authorities can only prevent the spread of the zebra and quagga mussels with education. But researchers hope to develop a biopesticide for the mollusks on a commercial level.
A solution from the soil
The Rocky Mountains may have provided California waterways with the relative isolation to give researchers in the east a headstart on finding a solution to combat the two invasive shellfish before coming here.
Dr. Daniel Molloy said research began nearly 20 years ago to find a solution to the zebra and quagga mussels.
Before the mussels arrived, Molloy had discovered a soil bacteria that kills the black fly, a pest in the eastern United States.
Using similar techniques, researchers isolated Pseudomonas flourescens, a soil bacterium that is toxic to zebra and quagga mussels.
“The remarkable thing about this bacteria is we’ve tested it against fish – we’ve tested it against other types of aquatic organisms, and it doesn’t kill them,” Molloy said.
In August 2007, the New York State Museum teamed with Davis-based Marrone Organic Innovations to develop the research into a commercially viable product.
Marja Koivunen, research and development director for Marrone Organic Innovations, said research on the bacteria is promising, but more work needs to be done.
Another hurdle the company faces is the U.S. Environmental Protection Agency, which will register the biopesticide before allowing it to be sold commercially.
Researchers would like to raise the biopesticides kill rate to 95 percent, and also must learn how to develop the bacteria on a commercial scale and what form it will take.
Koivunen said it could come in powder form, but particles must be a specific size.
“If it’s too big, the mussels will not take it in,” Koivunen said. “If it’s too small, it will be filtered out.”
The EPA will likely want researchers to further isolate the active ingredient in the bacteria that kills the mussels, Koivunen said.
Marrone Organic Innovations has applied for National Science Foundation grant funds for the research and should know more by March 1.
If the grant doesn’t come through, it may not stop the company from developing the product.
“Even before we knew it was a threat to California, the investors felt this is something we need to do,” Koivunen said.
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