Posted on 01/25/2007 9:46:54 PM PST by NormsRevenge
LOS ANGELES
Federal, state and local officials are on the hunt for an invasive mussel that has been spotted in California for the first time ever and could clog water supply pipelines.
Quagga mussels were found earlier this month at Lake Mead in Arizona and at Lake Havasu near the Whitsitt intake facility for the Metropolitan Water District of Southern California.
The discoveries launched a wider search for infested reservoirs and pipelines in California that are connected to the Colorado Aqueduct.
The aqueduct delivers water to an estimated 18 million people in urban Southern California, including Los Angeles and San Diego. The mussels can choke pipelines and threaten native species of fish by competing for their food.
"I suppose when people ask what level of concern we have, it's high and what level of effort we're putting in, it's considerable," said Mic Stewart, manager of water quality at the Metropolitan Water District of Southern California.
Officials will shut down the entire aqueduct for three weeks in March to dry out the canals and will use chlorine to kill the mussels. Even so, because the freshwater mollusks multiply rapidly with a single female laying as many as 1 million eggs it is unlikely that action will completely rid the state of the hardy mollusks.
"They're extremely difficult to eradicate," said Bob Muir, spokesman for the water district. "It's more a matter of trying to control them."
The invasive mussels likely hitched a ride on a private boat from Michigan's Great Lakes to Lake Mead and Lake Havasu. Because the mussels are young between 6 months to 2 years old officials are hopeful that they can manage the situation.
Divers in California, Arizona and Nevada continued the search for the mussels in a coordinated multi-agency effort this week.
In California, they searched the inlet tower of Diamond Valley Lake near Hemet, Lake Matthews in Riverside County and Lake Skinner near Temecula. So far the searches have not produced any more mussels.
The California Department of Fish and Game and the water district launched a public information campaign to tell boaters how to recognize and deal with the mussels. They have also set up checkpoints in Yermo, Needles and Blithe where boats and trailers are being searched for mussels. Similar searches are also taking place at Lake Skinner and Diamond Valley Lake.
The freshwater mollusks were accidentally introduced to the Great Lakes region in the ballast of ships from eastern Europe and the Ukraine. They can plug pipes up to 12 inches in diameter, and restrict flow in larger pipes. The colonies can also speed corrosion of pipes and other underwater infrastructure.
Until the quagga mussels were found this month in Lake Mead, they had not been spotted in the western United States.
"Depending on if they become established in California, they can be devastating to the state's environment and economically because of the effort necessary to try and eradicate them," said Troy Swauger, spokesman for the state's Department of Fish and Game. "At this point we're not sure if they are seriously established in the state and we're not sure if it would be possible to eradicate them."
Is there some natural predator feeding on them? Say, some fish species?
Doesn't look like it,,
mainly
chemical (e.g., oxidants and nonoxidizing organic molluscicides, pH depression) or nonchemical in nature (e.g., pipeline pigging, manual cleaning, and thermal treatment). Each control strategy has associated benefits, costs, and risks.
--
Zebra and Quagga Mussel Control Measures
Cornell University
http://www.utilities.cornell.edu/utl_lsceis_mussels.html
excerpt
--
LSC=Lake Source Cooling
--
Various strategies to control mussels, including both chemical and nonchemical forms, are available. No single control will protect all components of the LSC system, so a combination of controls have been considered. Controls that would prevent settlement of mussels on a majority of the LSC system components are all chemical in nature (e.g., chlorine and copper ion generation). Reactive controls allow mussel fouling to occur between treatments and can be chemical (e.g., oxidants and nonoxidizing organic molluscicides, pH depression) or nonchemical in nature (e.g., pipeline pigging, manual cleaning, and thermal treatment). Each control strategy has associated benefits, costs, and risks.
The mussel control strategy to be employed for the LSC system will include: (1) the physical pigging of the intake and outfall pipe, as needed (twice per year maximum); (2) manual cleaning of the outfall diffuser nozzles and heat exchangers as necessary; and (3) annual system shutdown, during which the temperature of the water within the heat exchange facility and associated piping will be raised to about 38°C (100°F). Established mussels will be killed by exposure to this elevated temperature. The thermal treated water will be blended with lower temperature lake water prior to discharge to the lake. This control strategy will rely on infrequent mechanical controls and temperature manipulation to control mussels. Cornell has selected a nonchemical control strategy to minimize any potential secondary environmental impacts associated with mussel control.
But are they good to eat?
Clogging pipes that American mussels refused to clog.
from what I read,
No..
The mussels can choke pipelines and threaten native species of fish by competing for their food.
It's rape, I tell you, RAPE! Its threatening "endangered species"!
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.