[Water_news] 3. DWR'S CALIFORNIA WATER NEWS: WATERSHEDS - 9/20/07

Department of Water Resources

California Water News

A daily compilation of significant news articles and comment

 

September 20, 2007

 

3. Watersheds

 

INVASIVE SPECIES:

Wasp could be recruited to battle arundo; Insect that weakens invasive plant found nearby - Ventura County Star

 

DELTA ISSUES:

Editorial: A new day for the delta - San Francisco Chronicle

 

 

INVASIVE SPECIES:

Wasp could be recruited to battle arundo; Insect that weakens invasive plant found nearby

Ventura County Star – 9/19/07

By Zeke Barlow, staff writer

 

As it turns out, the biologist only had to go as far as the Santa Clara River in his hometown of Santa Paula. It is there that Dudley thinks he's found something to help combat the weed that has taken over countless miles of rivers in Ventura County and cost millions of dollars to eradicate across the West.

 

Dudley and other biologists at the UC Santa Barbara Marine Science Institute found a tiny, non-native wasp that lays eggs in the stems of arundo, which leads to weakened plants. Weak plants are susceptible to other pathogens that could kill the plant and stop its spread.

 

The wasp isn't capable of stinging people, he said.

 

"There are good aliens and bad aliens," Dudley said. "Arundo is the bad one, so we are going to bring in the good ones to knock them out."

 

Scientists around the country are working on ways to stop the weed that chokes waterways, sucks up valuable fresh water and forces out native plants. Ventura County recently launched a $5 million project using chemicals to try to rid Matilija Canyon of the plant.

 

A team of researchers in Texas was working on importing the wasp from Europe — where it, and arundo, come from — when Dudley found some of the bugs boring into arundo stalks at a 20-acre study site on the Santa Clara River. He, too, had been looking far and wide for a bug that would harm the arundo.

 

After more exploring, Dudley found the tiny wasp, Tetramesa romana, all around California's south coast.

 

"It's a really big step that this is already here and quite widespread in Southern California," he said.

 

The problem is that arundo populations are terribly dense in some areas, so the wasps aren't doing enough damage. And they aren't a silver bullet, Dudley said.

 

The wasps' boring into the stem weakens the plant but doesn't completely kill it. The best way to get rid of the plant is to have the wasps do their work while another pathogen, such as a fungus, is introduced to finish off the arundo.

 

Dudley is studying the wasps around Ventura County and plans to introduce some to the Santa Ynez River in northern Santa Barbara County to determine the impact.

 

He said tests in the laboratory show the wasp doesn't feed on other plants and doesn't compete with other native bugs.

 

Because the wasps already live in this country, they could be used across the West within five years, Dudley predicted. Still, regulations could easily double that timeline, he said. If he gets permits and funding, he'd like to introduce more of the bugs around the West in larger populations so they could help tackle the arundo problem.

 

Jeff Pratt, director of the Ventura County Watershed Protection District, which is overseeing the arundo removal program in Matilija Canyon, said any solutions to the problem are good.

 

"It's viewed by everyone as noxious and out of control," he said of arundo. "This is a tremendous pest. Anything that is more environmentally friendly or less costly would be welcome." #

http://www.venturacountystar.com/news/2007/sep/19/wasp-could-be-recruited-to-battle-arundo/

 

 

DELTA ISSUES:

Editorial: A new day for the delta

San Francisco Chronicle – 9/19/07

 

GOV. Arnold Schwarzenegger's Delta Vision Blue Ribbon Task Force has completed the first draft of its vision. The 15-page plan hits all the right notes - namely, it recognizes that if we want California's cities and agricultural industries to continue thriving, we simply can't keep draining the delta - we have a few suggestions for the revision.

 

-- Get serious about what kind of "water provision" the compromised delta will realistically be able to provide for the future. The plan optimistically speaks of a future in which the delta has both a protected ecosystem and the ability to provide water to contractors around the state. This all sounds great, but current practice proves otherwise. For decades farmers and regional authorities have understood that pumping water out of the delta will lead to the collapse of its ecosystem - which, in a time of climate change, spells disaster for the Sacramento region and, for the rest of us, highly compromised water quality down the road. Still, no one has stopped pumping water. Is it realistic to think that we can do both at once? If it's not, which one of those priorities is more important to the state?

 

-- What can be done to strengthen other weak links in California's water supply? As the plan wisely points out, the entire state relies too heavily on the delta both for its water and its conveyance. So where else can regions get their water in a sustainable matter? Are more dams necessary, as the governor keeps insisting, or can we make better use of the ones we already have?

 

By acknowledging that the current state of affairs is woefully unacceptable, and urging ecological protection and regional self-sufficiency, the task force members have boldly staked out a new direction for California's water policy. Changing this status quo wasn't ever going to be easy. But as the collapsing delta shows, it's more necessary than ever. #

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/09/19/EDOIS8LK1.DTL&hw=water&sn=003&sc=498

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