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By Gig Conaughton
North County Times
January 27, 2006
SOUTHERN
CALIFORNIA ---- An invasive Ukrainian shellfish has created
fears among water officials that the rapidly multiplying
creature could overrun and foul waterways, clog water-delivery
pipelines and create billions of dollars in annual cleanup
costs.
California Department of Fish and Game officials discovered
"quagga" mussels in Lake Mead ---- one of the main
reservoirs for the Colorado River, one of Southern
California's main water supplies ---- this month.
Then,
10 days ago, divers from Southern California's main water
supplier, the Los Angeles-based Metropolitan Water District,
found the mussels attached to recreational boating facilities
in Lake Havasu, the Riverside County reservoir from which
Colorado River water begins flowing into Southern California.
Environmental scientists believe the mussel, which is often
smaller than a quarter but can grow to 4 centimeters in
length, slightly larger than a silver dollar, was brought to
the United States in the 1980s by ships that took in ballast
water in the Caspian Sea and purged it in U.S. waters.
Without any natural predators to keep its population in check,
the mussel has been a huge and expensive problem in the Great
Lakes for years. But it had never been found in California
until now.
The mussel is roundish in diameter and its color patterns can
vary wildly. It can have black, cream, or white bands, and
usually has dark concentric rings on the shell and is paler in
color near the hinge.
It creates several problems, officials said. It is voracious.
It eats phytoplankton and suspended particles in the water.
The former robs fish and other water animals of their natural
food supply. The latter "cleans" water and allows
sunlight to reach deeper depths than it would otherwise. That,
in turn, can cause algae blooms that can kill off fish and the
other animals in waterways. In addition, Eaton said, the
mussels release phosphorus as part of their waste, which can
make drinking water smell and taste bad.
The mussel can attach itself to pipeline and filter openings,
restricting water flow, can starve out other animals by
devouring their food supplies, and can foul water quality
through their waste, and by encouraging oxygen-eating algae
blooms.
"It creates potentially huge economic and environmental
problems," Troy Swauger of the California Department of
Fish and Game said Friday. "It's an invasive species. It
doesn't belong anywhere in the U.S. They multiply so rapidly
that pretty soon they're carpeting lake bottoms and river
bottoms."
However, Swauger said there's not much chance that the mussel
can be killed off because it has no natural predators in the
area. He said water and environmental officials can only hope
to contain and control its numbers.
Swauger said fish and game divers are continuing to search
waterways for the mussel and have created a toll-free number
for the public to report sightings and ask questions. They
also have issued emergency notices to recreational boaters in
the hope of stopping them from inadvertently spreading the
mussel, or its larvae.
Metropolitan Water District spokesman Bob Muir said that it
has also sent divers to several local reservoirs ----
including the massive Diamond Valley Lake near Temecula ----
but hadn't found any other mussels yet. Muir said the agency
plans to scour all 242 miles of the Colorado River aqueduct
for signs of infestation when it shuts down and drains the
pipeline in March, as part of a previously scheduled
maintenance project. Muir said the agency plans to use
chlorination to kill the mussels it finds.
Meanwhile, San Diego County Water Authority officials said
Friday that the city of San Diego has sent divers into a
number of reservoirs to look for signs of the mussel.
"Absolutely," said Gary Eaton, the Water Authority's
director of operations and maintenance. "Right now, the
biggest effort is to define the limits of where these things
are. We're inspecting boat hulls, water-craft launch areas,
places like that."
According to the U.S. Geological Survey, which collects,
monitors, analyzes, and provides scientific understanding
about natural resource conditions, issues and problems, the
quagga mussel accumulates organic pollutants in its tissues up
to 300,000 times greater than concentrations in the
environment. The agency said those pollutants are excreted and
can lead to greater pollution exposure to animals up the food
chain. Because of that, geological survey officials suggest
that people not eat quagga mussels.
Swauger said that environmental agencies have no plans to try
to find a natural predator for the mussel that could be
introduced to try to control its numbers.
He said that there may be natural predators for the mussel in
its native Eastern European habitat ---- but they would also
be an invasive creature here in the U.S. Adding them to the
mix could do even more environmental harm.
"What you have here is a Pandora's box," he said of
the quagga mussel discovery in California. "We wouldn't
be able to introduce anything. You'd have a potentially a
larger Pandora's box."
Swauger encouraged the public to call the Department of Fish
and Game if they thought they found mussels, or if they had
questions about it.
The number to call is 1-866-440-9530. For more information
about the quagga mussel, go to www.dfg.ca.gov/news/news07/07007.html
Contact staff writer Gig Conaughton at (760) 739-6696 or gconaughton@nctimes.com.
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