Department of Water Resources
California Water News
A daily compilation of significant news articles and comment
August 10, 2009
3. Watersheds –
War's on against invasive mussels
San Diego Union-Tribune
Study: Invasive mussels can survive in Lake Tahoe
North County Times
Wildfire burns remote area in Central Coast
Mercury-News
Mad River Bridge construction progressing smoothly
Eureka Times-Standard
A river protection
S.F. Chronicle
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War's on against invasive mussels
San Diego Union-Tribune-8/9/09
By Michael Gardner
Release the hounds. Pour the bacteria. Deploy ravenous fish.
Doable or doubtful, California and federal officials are sizing up diverse strategies in their frantic campaign to contain trillions of quagga mussels, dime-sized invaders threatening water and power supplies in California and across the Southwest.
“While we and everyone else continue to search for a method of controlling them, we haven't found the answer yet,” said Curt Brown, director of research and development for the U.S. Bureau of Reclamation.
Solutions may be on the horizon, however distant.
Most promising and closest to approval is a strain of common bacteria that is safe for humans, but produces a toxin so well disguised that it can sneak past a quagga mussel's self-defense mechanism of clamming up to protect itself from ingesting anything deadly.
Also being given tryouts are high-tech defenses, such as repellent coatings on pipes, ultraviolet light and quagga-trapping strainers with microscopic holes.
As a last resort, officials may consider introducing quagga-munching black carp, an aggressive invasive species. Already, dogs with a nose for quaggas hitchhiking on watercraft have joined the fight.
Originally from Ukraine, quagga mussels and their close cousin, the zebra mussel, became entrenched in the Great Lakes 20 years ago. For years, the Southwest appeared to have been spared – until Jan. 6, 2007. That's when a quagga was found in Lake Mead, which straddles Nevada and Arizona. From there, unsuspecting boaters provided free shuttles to other waterways.
“They are alive and well and multiplying rapidly,” Brown said.
Champion reproducers – a single quagga can produce 1 million eggs in a spawning season – the mussels quickly established colonies throughout the Metropolitan Water District's system tied to the Colorado River, as well as in San Diego County reservoirs, including San Vicente.
Left unchecked, quaggas can take over freshwater lakes and rivers, threatening to clog or damage plumbing, potentially squeezing water deliveries and limiting hydropower production.
“Right now, we're in a fight,” said Gary Eaton, director of operations and maintenance for the San Diego County Water Authority. “But I wouldn't say we're losing.”
For now, the state's defenses that ring Southern California have held, with the exception of one discovery in San Justo Reservoir near Hollister.
Water agencies and the Bureau of Reclamation have launched aggressive search-and-destroy missions.
“We can manage it now without sacrificing power,” said Leonard Willett, a federal mussel control coordinator based at Hoover Dam.
The march of the mollusks also menaces the environment. Quaggas are voracious filter feeders, drawing in plankton and other nutrients that other aquatic life depend on.
“They have quite an impact on the food supply,” said Fred Nibling, a biologist with the Bureau of Reclamation.
Today, none of the alternatives has dethroned the current quagga killer of choice, chlorine. But that's a costly chemical with its own environmental and public health risks. Chlorine-treated water must be treated with another chlorine-cleansing chemical before it can be discharged into a lake or stream.
Tactics are two-fold: control the spread, then eradicate. So far, preventing escapes from already infested waterways remains a challenge.
That's where the quagga-dogs come in. Boaters can be surprised by trained dogs sniffing out the mussels on vessels just pulled out of the water or on the way home.
The dogs' primary job is to detect evidence of poaching and smuggling game and fish, but since the first mussel was found they have been enlisted sporadically at checkpoints and at water's edge accompanied by their state Fish and Game handler.
“We don't have a lot of time to look for quagga mussels,” said Lt. Lynette Shimek, who oversees the program.
The cash-strapped state has about 20 of the highly trained dogs on patrol. Of those, three are based in Southern California, where mussels are entrenched. Wardens rely on donations to offset training and care costs.
The state Department of Food and Agriculture has added quaggas to checklists at inspection stations. Since the first find in Lake Mead, 249,000 boats, canoes and kayaks have been stopped in California. Of those, 21,728 were drained and dried after evidence of mussels were detected. Nearly 400 have been quarantined.
Meanwhile, in a private Davis laboratory and at Davis Dam downstream from Lake Powell, researchers are preparing a deadly meal for the mussel.
The main ingredient in Zequanox, a milky substance the color of lemonade, is a special strain of bacteria that appears to go undetected by the quaggas'self-defenses.
“They think it's food,” said Pam Marrone, founder of Marrone Bio Innovations, which develops natural defenses against pests.
If all goes well, a permit for limited use could be obtained from the Environmental Protection Agency this fall, Marrone said. That's still a tall order, given an arduous approval process.
One challenge is overcoming any public resistance. To many, adding bacteria to drinking water sounds appalling.
Marrone countered that humans routinely ingest bacteria.
“It's ubiquitous. It's found in soil, water, plants, whatever,” she said.
The bacteria used in Zequanox “has never been known to be toxic to humans,” Marrone said.
Still, to overcome any lingering doubt, researchers have found a way to kill the bacteria used in Zequanox without destroying the toxin that attacks the mussels.
Water officials are intrigued, but not sold.
“You can imagine the battle. . . . Think back to fluoride. Imagine what (opponents) are going to do when you tell them you're going to put a bacteria” in their drinking water, said Eaton of the San Diego water authority.
“We're a little leery of saying absolutely, this is it,” he said. “But we are very interested in seeing what they come up with.”
Nibling, of the Bureau of Reclamation, sounded the most enthusiastic.
“It's not some science-fiction strain. It's an everyday bacteria,” he said.
Tests at Davis Dam “came through with a sparkling record. It's amazing if we can find something that can kill mussels and nothing else,” he said.
Introducing carp to eat the sharp-shelled quaggas has not met with similar zeal. Still, Steve Robbins, general manager of the Coachella Valley Water District, sees value in allowing black carp to be used if the state's power and water delivery system is overrun.
“I haven't dropped the idea,” Robbins said. “We're being successful right now. But if we weren't successful” the district could seek a permit to use carp.
Nibling said some other species make meals of quaggas, such as the bottom-feeding redear sunfish.
“A number of fish eat quaggas,” he said. “The problem is they can't eat enough.”
QUAGGA MUSSEL FACTS
Originally from Ukraine, they were discovered in the Great Lakes two decades ago.
The tiny mussels were first found in the Southwest in 2007 at Lake Mead.
One quagga can produce 1 million eggs in a season.
They can deprive other aquatic life of food and clog water systems and hydroelectric works.#
Study: Invasive mussels can survive in Lake Tahoe
North County Times-8/9/09
Scientists say a new study shows invasive quagga mussels can survive and possibly reproduce in Lake Tahoe.
"This could potentially be catastrophic for the lake," said Ted Thayer, natural resource and science team leader for the Tahoe Regional Planning Agency.
The study by scientists at the University of Nevada, Reno, and UC Davis suggests that the low calcium levels in Tahoe's water may not provide sufficient protection against the mussels as once believed.
"It appears that for adults, that's not the case. They are able to survive," chief UNR researcher Sudeep Chandra said. "The hypothesis we were testing is there would be no survival. I was quite surprised."
Quagga mussels were first discovered in Lake Mead in 2007 and have since overrun the lake's ecosystem.
Scientists monitored eight mussels in tanks of Tahoe water over 51 days to study survival rates. Chandra said all but one survived ---- a rate of 87 percent. Forty-three percent of the mollusks showed the potential for reproduction.
Scientists say the study did not examine the survivability of mussels in their larval stage. Chandra and co-researcher Marion Wittmann, an aquatic ecologist for the UC Davis' Tahoe Environmental Research Center, say it's still possible that Tahoe's calcium levels could not support juvenile mussels.
"It's going to take a little more research to determine if this mussel can really sustain in populations over time," Wittmann said.
If established at Tahoe, quagga mussels or their cousin, zebra mussels, could cause profound changes to the alpine lake's sensitive ecosystem. The mussels could clog water intakes, cover boats and piers, and litter pristine beaches with sharp and reeking shells.
A recent study by the U.S. Army Corps of Engineers estimates a mussel invasion could cost Tahoe's tourism economy more than $22 million per year.
"This is disappointing," Thayer said. "It would have been nice if it had come back that there wasn't that high a risk."
TRPA and other agencies have taken steps over the past two years to prevent introduction of the mussels, including inspection of all boats launching into the lake.
Chandra said he believes the inspection programs and other aggressive measures can be effective.
"When you reduce the likelihood of transfer, almost always those ecosystems are protected," Chandra said. "Using sound science and good policy, the lake can be protected."#
Wildfire burns remote area in Central Coast
Mercury-News-8/9/09
A wildfire has burned about 10,000 acres in a remote part of northern Santa Barbara County.
Forest Service spokeswoman Juanita Freel says the blaze on Sunday is burning in steep, inaccessible terrain in the San Rafael Wilderness about 25 miles east of Santa Maria.
No structures are threatened and no injuries have been reported.
More than 600 firefighters, aided by at least a dozen water-dropping aircraft, were trying to knock down flames. There was no containment estimates.
The fire, which began Saturday afternoon, grew quickly through the day. The blaze chewed through heavy brush and temperatures were in the mid-90s.#
http://www.mercurynews.com/breakingnews/ci_13028434?nclick_check=1
Mad River Bridge construction progressing smoothly
Eureka Times-Standard-8/09/09
The construction of new U.S. Highway 101 bridges over the Mad River near McKinleyville has started and is proceeding smoothly, according to Caltrans.
Once complete, the two new bridges will have improved lighting and wider shoulders, while the northbound bridge will include a separate path for bicyclists and pedestrians.
Part of the challenge of the project has been completing the preliminary work with as little disruption as possible to aquatic life.
”In mid-June 2009,” according to a press release, “a Fish Exclusion Zone (FEZ) and a fish migration corridor were constructed in the river to exclude fish from areas of the river where sound levels from pile driving were estimated to exceed regulatory limits. This FEZ extends 500 feet in either direction of the construction area, and was put in place for the protection of aquatic life and for public safety during this portion of the construction project.”
The pile-driving operations are expected to be complete soon, at which time the fish exclusion zone will be dismantled, according to Caltrans.
However, boaters' access to the work area may still be restricted temporarily. In June, Caltrans announced that boaters would have to leave the river and pack their vessels through the restricted area.
Caltrans officials credited the success for the project thus far to teamwork and cooperation with permitting agencies.
The $50 million project is expected to take four to five years to complete and will replace the existing spans built in 1929 and 1958.
The new seismically sound bridges will not have pilings in the water, which will avoid scouring that often threatens the integrity of older bridges.#
http://www.times-standard.com/ci_13025973?IADID=Search-www.times-standard.com-www.times-standard.com
A river protection
S.F. Chronicle-8/10/09
Editorial
What we said: "California's rivers are diverted, drained and dammed. They're also sullied by a form of mining, a little-controlled practice known as suction dredging that scours river bottoms with vacuum pumps in search of gold. On Gov. Arnold Schwarzenegger's desk is a measure that would halt the activity while the state studies the effects on fish and water quality." - Editorial, July 17, 2009
What happened: Last week, Gov. Arnold Schwarzenegger signed the bill, SB670 by Sen. Patricia Wiggins, Öa Santa Rosa Democrat, Öinto law.
What's next: It places an immediate moratorium on the dredging - done with small motorized floats along North Coast and Sierra foothill rivers.
The state Fish and Game Department will study the impacts of the mining, which can stir up buried toxics such as mercury and create muddy clouds that smoother fish spawning beds.
What you can do: E-mail your feedback to Schwarzenegger at governor@governor.ca.gov.#
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/08/10/EDUD195429.DTL
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