Friday, December 21, 2007

Alien Shellfish Invade Arizona

from: Arizona Game and Fish.
Lake Pleasant is the site for next month's Arizona Yacht Club Birthday Regatta and Leukemia Cup.

Quagga Mussels in Lake Pleasant

Posted by: "tabband" tabband

Thu Dec 20, 2007 9:37 am (PST)

Arizona Game and Fish Department

Dec. 19, 2007

Quagga mussel invasion confirmed at Lake Pleasant Boaters asked to
inspect their vessels for aquatic hitchhikers

PHOENIX -- Quagga mussels have been discovered at multiple sites at
Lake Pleasant, and state wildlife officials are requesting that
boaters and other recreationists take simple steps to help prevent
this Eastern European menace and other aquatic hitchhikers from
spreading to other lakes.

On Dec. 17, small adult mussels were collected from a dry-docked boat
that had been moored at Pleasant. A team of biologists from the
Arizona Game and Fish Department also discovered mussels in the
southern end of the lake from boat slips at the Lake Harbor Marina, at
the Pleasant Harbor Marina boat launch, and the 10-lane boat ramp
courtesy dock. Those invasive mollusks have been confirmed as quagga

Quagga mussels, which have caused millions of dollars in damage in the
Great Lakes region, were first discovered at Lake Mead in January of
this year. Since then, they have been confirmed in lakes Mohave and
Havasu and their presence has been suspected, but not confirmed, at
Lake Powell. This past fall, quagga mussels were discovered in a
segment of the Central Arizona Project (CAP) Canal in Scottsdale. The
CAP canal originates at Lake Havasu. Water from the CAP is used to
fill Lake Pleasant.

"We suspected that it was just a matter of time before quagga mussels
became established in Lake Pleasant, but we hoped it wouldn't happen
so soon," said Larry Riley, a fisheries biologist with the Arizona
Game and Fish Department.

Riley, who is heading the Quagga Team for the state wildlife
department, pointed out that a single quagga mussel can produce 30,000
to 40,000 fertilized eggs in a single breeding cycle. One adult female
quagga can release up to a million eggs in a single year.

Game and Fish Department officials are asking all boaters and anglers
throughout the state to help fight the continuing spread of these and
other invaders by routinely taking simple precautionary steps each
time they visit a waterway anywhere in the state.

Riley added that the presence of other invasive species, such as
golden algae, means all boaters and other water recreationists should
take simple, precautionary steps � every time they go to a lake, river
or stream.

Before leaving a lake or other waterway, always:

* CLEAN the hull of your boat, remove all plant and animal material.
* DRAIN the water from the boat, livewell and the lower unit.
* DRY the boat, fishing gear, and equipment.

If you are a day user, please wait five days before launching your
boat someplace else. This five-day waiting period will aid
tremendously in killing those hidden hitchhikers on your boat, such as
the microscopic quagga larvae. Also, it is a good idea to wash the
hull of your boat with high-pressure water, either at the lake, if
washers are available, or after leaving the waterway.

Visiting a self-help car wash that has high-pressure soapy water is an
excellent idea either on your way home, or while on the way to the
next lake � it can even help keep your boat looking new. Or, giving
your boat a hot soapy bath when you get home can also help protect
your investment and while also helping protect the next lake you visit.

Remember, many of these aquatic hitchhikers can harm your boat as
well. These invaders will attach themselves to boats and can cause
damage to boat motors if they block the flow of cooling water through
the engine.

If you are moving a boat that has been moored on a mussel-positive
lake, please take at least one of these extra precautions:

* Power wash the hull so that it is clean "to the touch"
* Bilge decontamination that consists of either a 140-degree hot water
flush of the bilge spaces or
* A household vinegar flush of the bilge spaces, or
* A mandatory minimum 27-day desiccation period where the boat is
removed from the waterway and allowed to dry out; all through-hull
fittings and bilge plugs must be opened to the air with no residual
lake water allowed to remain standing in the bilge spaces; if, for any
reason, water cannot drain or standing water remains in the bilge, it
must be treated with heated water or vinegar solution.

Quagga mussels do not pose a known threat to human health. Biologists
are concerned that quagga mussels may cause ecological shifts in the
lakes they invade, with consequences to valued wildlife resources.

Because these invasive mussels attach to hard surfaces like concrete
and pipes, they will affect canals, aqueducts, water intakes and dams,
resulting in increased maintenance costs for those facilities.

Quagga mussels are small, freshwater bi-valve mollusks (relatives to
clams and oysters) that are triangular in shape with an obvious ridge
between the side and bottom. The zebra mussel, a close relative of the
quagga, gets its name from the black- (or dark brown) and
white-striped markings that appear on its shell.

Quagga mussels are native to the Dneiper River drainage of the
Ukraine. Zebra mussels are native to the Caspian, Black, and Azov seas
of Eastern Europe.

These exotic mussels were first discovered in the United States in
Lake Saint Clair, Michigan, in 1988 and are believed to have been
introduced in 1986 through ballast water discharge from ocean-going
ships. Since their initial discovery, zebra mussels have spread
rapidly throughout the Great Lakes and Mississippi River Basin states
and other watersheds throughout the eastern and central United States.
Quagga mussels have not spread as extensively.

These invasive mussels in Lake Mead are 1,000 miles farther west than
any other known colony of zebra mussels. The primary method of
overland dispersal of these mussels is through human-related
activities. Given their ability to attach to hard surfaces and survive
out of water, many infestations have occurred by adult mussels
hitching rides on watercraft. The microscopic larvae also can be
transported in bilges, ballast water, live wells, or any other
equipment that holds water.

They are primarily algae feeders. They feed by filtering up to a liter
of water per day through a siphon. These mussels consume large
portions of the microscopic plants and animals that form the base of
the food web. The removal of significant amounts of phytoplankton from
the water can cause a shift in species and a disruption of the
ecological balance of a lake or other waterway.

These mussels can settle in massive colonies that can block water
intake and affect municipal water supply and agricultural irrigation
and power plant operation. In the United States, Congressional
researchers estimated that zebra mussels alone cost the power industry
$3.1 billion in the 1993-1999 period, with their impact on industries,
businesses, and communities more than $5 billion.
For more information, click here or visit

Kelley Fowke
Arizona Game and Fish Department

Boating Education Coordinator
phone 623-236-7381
cell 602-568-0638
fax 623-236-7903
New address: Arizona Game and Fish Department
5000 W. Carefree Highway
Phoenix, AZ 85086-5000


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