Officials Fear Spread of Invasive Mussel Plague

[Pastor Dale Morgan]

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Plagues, Pestilences and Diseases*

Aug 10, 6:03 PM EDT
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Officials Fear Spread of Invasive Mussel Plague*

By MOISES D. MENDOZA
Associated Press Writer

PHOENIX (AP) -- A plague of invasive mussels that made its way west of
the Rocky Mountains seven months ago is spreading rapidly, just the
scenario most feared by officials running water systems supplying
millions of people across the Southwest.

The thumb-sized quagga mussels, which can clog pipes and gum up
waterworks, have already been discovered in lakes Mead, Havasu and
Mojave on the Colorado River and in two major aqueducts that supply
water to Southern California and Arizona.

Officials announced this week that they had also found tiny quagga
larvae in Lake Powell on the Arizona-Utah border, although no adults
have yet been found. Most interior lakes have staved off infestations -
for the time being.

Quagga mussels, close cousins of the better known zebra mussels, are
almost impossible to totally exterminate. The small clam-like creatures
damage local aquatic life and can cause millions of dollars in damage to
water facilities. They also damage marinas and boat motors.

The big fear is that the mussels will infiltrate canals and pipelines
feeding the Southwest's vast system of reservoirs and water treatment
plants, sending maintenance costs skyrocketing.

And, already, the mollusks are making water treatment managers squirm.

In March about 800 mussels were found in the 242-mile Colorado River
Aqueduct, which supplies water to 18 million people, said Bob Muir, a
spokesman with the Metropolitan Water District of Southern California.

Portions of it were closed for 10 days in July to inspect the system and
destroy larvae.

Officials are spending $5 million for a special control system that
includes increased water chlorination and equipment that will help them
evaluate quagga infestations, Muir said.

"It's a matter of controlling and containing them. We'll never be able
to truly eradicate quaggas from our system," he said. "We've seen in the
Great Lakes that when they mass produce, they can clog pipelines, they
can disrupt water distribution systems."

A few mussels have also been discovered in the Central Arizona Project
aqueduct, which draws water from Lake Havasu and delivers it as far
south as Tucson.

The quasi-public agency is trying to prevent their spread by stocking
the aqueduct with redear sunfish, which are thought to eat the mussels,
said John Newman, an assistant general manager.

"We just really don't know what will happen at this point," Newman said.

Other agencies are quickly creating plans to deal with their spread.

The Salt River Project, which provides water and power to the Phoenix
metropolitan area, plans to scrape them away, use pesticides and try
special paint coatings that repel the mussels. Though none have been
spotted in the project's reservoirs, their spread is practically
inevitable, said Brian Moorhead, an environmental scientist for the
public agency.

Prevailing wisdom is that ships emptying ballast water are responsible
for introducing quagga mussels to the Great Lakes in the 1980s, where
they've caused at least $1 billion in damage. To come out West, they
likely hitched rides inside ballast tanks or on the bottom of boats that
weren't washed carefully.

In 2006, authorities exterminated zebra mussels at a quarry in Virginia
by raising potassium levels to poison them. But that would be
logistically difficult in larger bodies of water and could harm plants
or animals, said University of Texas at Arlington biology professor
Robert F. McMahon, who studies zebra and quagga mussels.

Once quagga mussels arrive, they're usually there to stay, he said.

"The best way to avoid these problems is to prevent them in the first
place," McMahon said. "There are all sorts of non-indigenous species
that have been introduced to the United States. This is just an example
of what some of these species can do."

In an attempt to prevent the mussels' spread, authorities are urging
boat owners to thoroughly inspect and wash their vessels before putting
them in the water. At some lakes, including Lake Powell, boats must be
decontaminated before entering the water.

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On the Net:

Information on quagga and zebra mussels http://www.100thmeridian.org

Metropolitan Water District: http://www.mwdh2o.com/

Central Arizona Project: http://www.cap-az.com/

Salt River Project: http://www.srpnet.com/