A daily compilation of significant news articles and comment
January 18, 2008
3. Watersheds
ZEBRA MUSSELS:
Don't move a mussel; expert explains all about invasive shellfish - Hollister Freelance
DELTA ISSUES:
Death in the Delta - High Country Times
ZEBRA MUSSELS:
Don't move a mussel; expert explains all about invasive shellfish
Hollister Freelance – 1/16/08
By Michael Van Cassell, staff writer
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
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
State officials confirmed Monday the presence of zebra mussels in San Justo Reservoir - which is connected to
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
"Zebra mussels in
The discovery in San Justo Reservoir marks not only the first in the state, Molloy said, but also west of
Since the mussels were brought to American waters - most likely in the ballasts of ships from
Zebra and quagga mussels are native to the Caspian Sea and eventually spread throughout Europe, but the Ural Mountains saved
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
"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
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
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
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
Also check out: the story that broke the news that zebra mussels were present in the reservoir and a story about how area customers received water from the reservoir during a four-week period.
A few facts about the zebra mussel
The zebra mussel is a prolific breeder that feeds off the bottom of the food chain and can clog water pipes, valves and pumps. It is native to the Caspian Sea, has spread throughout Europe and was first found in the
A recent discovery of the species in San Justo Reservoir south of Hollister marks the first time the mussel has been found west of
DELTA ISSUES:
Death in the Delta
High Country Times – 1/17/08
Fish populations continue to tank in the Sacramento-San Joaquin Delta, according to figures released last week by the California Department of Fish and Game.
After tossing the trawl nets and tallying the numbers, the agency found a record low population of longfin smelt in the
“These data are just one more clear indication that the overall ecosystem of the Delta is in dire straits,” says Christina Swanson, senior scientist at The Bay Institute, a nonprofit that protects the
The state’s Department of Fish and Game agrees that the fish are in serious trouble. “We’re very concerned about the trend that these data indicate,” says Marty Gingras, supervising biologist. The department says it cannot determine exactly how close to extinction the five species are, because the survey compares current fish populations to past abundance rather than providing a precise tally of the number of fish. Nonetheless, says Gingras, “there is merit in listing longfin smelt under the California Endangered Species Act, and uplisting the Delta smelt from threatened to endangered.”
A major factor harming the Delta’s fish is the overdraft of water from Delta watersheds. State and federal records indicate that water project diversions, which supply 24 million Californians and a $31 billion dollar agricultural industry, gulp an average of nearly 2 trillion gallons of Delta water per year. That’s more than half of the water that trickles into the Delta in a dry year, and 20 to 30 percent of total flows in a wet year.
“Clearly these data are confirming that we regularly take too much water out of the Delta and rivers,” says Swanson. The Bay Institute recommends that the state consider higher water efficiency, better management of groundwater, and water recycling to ease Delta demand.
Other problems threaten the Delta’s fish as well. Non-native species, such as the overbite clam, tend to out-compete natives and create less suitable habitat for them. Additionally, the water contains unhealthy levels of herbicides and pesticides from upstream agriculture and ammonia from sewage.
Habitat loss is another important factor in the Delta. Over the past 150 years, most of its marshes and waters have been leveed, drained and rerouted for agricultural and urban development.
A recent court ruling may provide some relief for the Delta’s fish. Last August, U.S. District Court Judge Oliver Wanger of
http://www.hcn.org/servlets/hcn.Article?article_id=17474
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