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[Water_news] 3. DWR'S CALIFORNIA WATER NEWS: WATERSHEDS - 6/4/08

Department of Water Resources

California Water News

A daily compilation of significant news articles and comment

 

June 4, 2008

 

3. Watersheds –

 

 

 

Invasion of the mollusks: Quagga and zebra mussels pose a threat to California.

The Fresno Bee – 6/3/08

 

Davis Lake healthy, open for fishing

The Stockton Record 6/4/08

 

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Invasion of the mollusks: Quagga and zebra mussels pose a threat to California.

The Fresno Bee – 6/3/08

By Marek Warszawski

 

Central California lakes and waterways are being threatened by tiny mollusk invaders that pose as hitchhikers.

 

Because quagga and zebra mussels are spread primarily through human-related activities, the Department of Fish and Game is asking for cooperation from boaters to prevent these destructive species from gaining a foothold in the San Joaquin Valley.

 

Many other areas of the state have been on high alert since last fall, when quagga mussels were discovered in numerous places along the Colorado River drainage, including Lake Mead, Lake Havasu and several San Diego-area reservoirs. Closer to home, zebra mussels were found inhabiting San Justo Reservoir outside Hollister in January.

 

Although these close cousins, which belong to the same family of shellfish, have yet to turn up in the Valley, their history suggests it's only a matter of time.

 

"Right now there's not really anything keeping people from coming up here and spreading these mussels," said Mark Watson, the quagga/zebra mussel biologist for DFG Region 4, which is headquartered in Fresno. "People need to be educated."

 

Once established, fast-reproducing quagga and zebra mussels can destroy a lake's ecology by overwhelming vital elements of the food chain. They also can clog waterway infrastructure and damage boats.

 

Quagga and zebra mussels are typically about the size of a fingernail but can grow up to 2 inches in diameter. After attaching to hard surfaces, including metal, glass, plastic and wood, they feed themselves by consuming microscopic plants and animals from the water. Each adult mussel can filter up to one liter of water per day.

 

"They filter out all the food, and the native fish don't have anything left to eat," Watson said. "It basically changes the whole ecosystem."

 

These invaders colonize on hulls, engines and steering components of boats and other watercraft. Reproducing rapidly, they also can attach themselves to piers, pipes and fish screens, blocking water intake and hampering municipal water supplies, irrigation systems and power plants.

 

The potential economic impacts are staggering.

 

"The consequences can be very severe," said Steve Haugen, watermaster of the Kings River Water Association. "Once they get here, it's management of them -- not elimination. You have to live with them."

 

Quagga and zebra mussels are native to Russia and the Ukraine. Biologists theorize that they came to the U.S. in the mid-1980s on cargo ships bound for the Great Lakes.

 

Zebra mussels were first detected in Lake St. Clair in 1988. A year later, quagga mussels were found in the same area. By the late 1990s, both species had spread to 23 states and two Canadian provinces.

 

Once these invasive mussels started turning up in California, alarm bells began to sound.

 

All vessels launching at Lake Tahoe face mandatory inspections, and owners who refuse are subject to a $5,000 fine. Officials in Santa Clara, San Luis Obispo and Lake counties also have instituted mandatory inspections -- with boat owners in Santa Clara County being charged a $7 inspection fee. Last week, the East Bay Regional Park District banned all out-of-state boats from its four Bay Area reservoirs.

 

So far, the response throughout the central San Joaquin Valley has been noticeably less urgent. Recreation and water officials are mainly relying on public education to get the word out.

 

Calvin Foster, area manager for the U.S. Army Corps of Engineers, which manages recreation on several area reservoirs, said his agency is in the discussion and planning stages with the DFG.

 

"We don't have any room in our budget to just go out and inspect boats," Foster said. "But we'll support those activities, for sure."

 

At Millerton Lake, supervising ranger Lt. Gideon Coyle said the Department of Water Resources recently tested for quagga and zebra mussels but he had not heard the results.

 

Even though he hasn't received any directives on how to deal with mussels, Coyle said he has handed out fliers and discussed the issue with boat owners. He described current awareness levels at Millerton Lake as "very low."

 

"Out of 10 boaters I talk to about these mussels, maybe one in 10 knows what they are," Coyle said. "Most people go, 'What are you talking about? What's a quagga mussel?' "

 

Watson, the DFG biologist, said the best way to keep quagga and zebra mussels from spreading is through proper care by boat owners.

 

Vessels must be thoroughly washed and dried upon leaving the water, including bilge pumps, live wells and outboard unit, and should sit for at least five days between trips to different freshwater lakes.

 

Why so long? Quagga and zebra mussels can survive out of water for up to a week.

 

"Keep your boat clean and dry before you launch it," Watson said. "That's the best advice I can give."#

 http://www.fresnobee.com/sports/story/644980.html

 

 

 

Davis Lake healthy, open for fishing

The Stockton Record 6/4/08

By , Outdoors Columnist

 

PORTOLA - As a young man, Justin Dollard remembers wading into Davis Lake, casting a fly and hooking trophy trout after trophy trout. There were so many big rainbows. Today, 20 years later, Dollard hopes the once-famous fishing lake will return to its past glory.

 

"Being a passionate angler, I could catch trout that were all immense in size," he said. "Back then, Davis Lake was among the top-five trout fishing destinations west of the Rockies. I believe it will be again."

 

Fact is, Davis Lake is starting over. More than 1 million Eagle Lake rainbow trout will be stocked this year in an all-out effort by the state Department of Fish and Game to help the impoundment return to prominence. Some of the trout will be lunkers, 3 to 15 pounds.

 

"We hope to quickly re-establish Davis Lake as a high-quality trout lake," said Donald Koch, director of the DFG.

For anglers like Dollard, the change couldn't come sooner.

 

In September 2007, the lake's fishery was completely killed when the state moved to eradicate the predatory, non-native northern pike that had been illegally introduced. Officials treated the Plumas County reservoir and its tributary streams with CFT Legumine - a new liquid form of rotenone - one of the only chemicals licensed to kill fish in California. Of course, when they killed the pike, the trout were anihilated, as well.

 

Davis Lake had been negatively impacted by the voracious pike since the mid-1990s. Pike - some as large as 46 inches and weighing between 25 and 30 pounds - readily ate the less-aggressive trout. Anglers endured negative experiences at the lake because of the diminishing numbers of rainbows. After the lake was treated, only 1 percent of the 48,900 pounds of dead fish recovered were trout.

 

State officals believed the lake had to be treated because of the threat of the invasive pike that might have escaped from the reservoir and swam downstream through the Sacramento River and into the Delta, and caused irreseversible ecological and economic harm.

 

An attempt to eradicate the pike in 1997 was unsuccessful and controversial, with little public support. It took 11 years before a coalition of local citizens, state and federal agencies agreed on a plan to rid the lake of pike. The plan was carried out eight months ago.

 

"The lake is healthy again, and the fishery should continue to get back on its feet," Dollard said. "A whole age timeline of fish are being stocked from fingerlings and sub-catchables and catches, up to some real large broodstock. Most all are Eagle Lake-strain rainbows, a superior fighting fish."

 

While the lake is literally plugged with trout, including major releases of rainbows as large as 15 pounds just before Memorial Day and 31,000 catchable-sized to 3-pounders in January, fishing has been pretty slow for bank anglers and fly fishers. Only trollers are enjoying "wide open" action and quick five-fish limits.

 

"Fishing is slow to come back," Karen Mazingo of Portola said. "But the trout are in the lake, and there are tens of thousands more coming."

 

Dollard touts trolling about 6 feet deep with wooly bugger flies, Needlefish or Dick Knight lures. There hasn't been a sustained warming trend, so the bulk of the trout are hanging just under the surface.

 

Davis is about half-full and won't fill this year. Though last winter came early, it wasn't wet, so runoff will be below par. Boat ramps are open at Honker Cove and Camp 5. The U.S. Forest Service has installed new docks, toilets and hiking trails, and three lakeside campgrounds at Grasshopper, Grizzly and Lightning Tree are accommodating summer vacationers.

 

"People seem excited to get back up to the lake," said Dollard, who acknowledged there are fewer travelers this year because of higher fuel prices. "Most who are coming are anglers, and they've given an economic boost to the whole region. They've made an immediate, positive impact, and the prospect of catching quality-sized rainbows will keep them coming."

 

Dollard, who manages a retail market in Portola, said most of the trout he's seen have weighed 5 to 8 pounds. Some trout have $10 reward tags that Fish and Game will use to determine catch and growth rates at the nutritionally rich lake.#

http://www.recordnet.com/apps/pbcs.dll/article?AID=/20080604/A_SPORTS03/806040310

 

 

 

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