Zebra mussels threaten Missouri
By the Missouri Department of Conservation
Published in the Jefferson City News Tribune on:
June 30, 2005
Every year, zebra mussels inch closer to Missouri's
So far the Show-Me State hasn't documented an infestation
of the striped invaders. However, that could change overnight
if boaters, anglers and marina owners are not careful.
The rewards for watchfulness include continued enjoyment
of clean water, pleasant beaches and good fishing.
Zebra mussels, which are native to the Caspian Sea, found
their way to into the St. Lawrence Seaway in the ballast
tanks of ocean-going ships in the mid-1980s. It took them
just five years to gallop across the Great Lakes. Then
they jumped from southern Lake Michigan into the Illinois
River. By 1991 they had reached the Mississippi River.
Since then, they have hitched rides to other North American
waters in anglers' bait buckets and on pleasure boats
and commercial craft. Live zebra mussels have even been
found attached to trailered boats in California.
Zebra mussels are amazingly prolific, covering any available
solid surface with thousands of individual animals per
square foot. They can cause increased utility bills when
they clog water intake pipes of power generating plants,
municipal water plants and other utilities. They also
damage boats, docks, buoys and other property on lakes
Removal is possible, but expensive. Industries around
the Great Lakes spend an estimated $3 million per year
to remove the mussels from their operating systems.
Zebra mussels can attach to power boats' drive units
and clog water intakes, causing damage to engines. They
feed on plankton, the microscopic plants and animals that
form the basis of the aquatic food chain. This puts them
in direct competition with native mussels and young fish,
including bass, bluegill and other popular sport fish.
State and federal agencies have spent millions of dollars
seeking ways to eradicate zebra mussels, but so far nothing
has been found to eliminate them without harming other,
Oklahoma officials have confirmed the presence of zebra
mussels in Grand Lake. One of the lake's tributaries,
Elk Creek, enters Oklahoma from southwest Missouri. Adult
zebra mussels and larvae also have been found at El Dorado
and Cheney lakes on the east and west sides of Wichita,
Kan. Adult zebra mussels also have been found in the Missouri
River at Sioux City, Iowa.
Steve McMurray, a resource scientist with the Missouri
Department of Conservation, said alert citizens have played
a key role in preventing zebra mussel infestations in
Missouri so far.
"One of our strongest lines of defense has been
marina operators," McMurray said. "We have caught
several infested boats before they went into Missouri
lakes and streams because marina personnel knew what to
look for and alerted us to the problem."
Boat owners appreciate help, says McMurray. Once they
realize that launching an infested boat could hurt fishing,
they are glad they found out in time.
Preventing the spread of zebra mussels isn't difficult,
but it requires attention. Just as ocean-going vessels
carried the invaders from Europe, pleasure craft can harbor
microscopic zebra mussel larvae in live wells, engine
cooling systems, bilge pumps or bait buckets. Once released
into uninfested waters, the animals grow and multiply
Missourians can slow the spread of the zebra mussel by
draining all bilge water, live wells, bait buckets and
any other water from their boats and equipment before
moving from one body of water to another.
Boaters should dispose of leftover live bait and should
inspect boat hulls, drive units, trolling plates, prop
guards, transducers, anchors and trailers, and then scrape
off and trash any suspected mussels, however small. They
should also remove all water weeds from boats and trailers
and flush boat hulls, drive units, live wells, bilges
and their pumping systems, trailers, bait buckets, engine
cooling water systems and anything that got wet with a
hard spray from a garden hose.
If your boat and trailer were in infested waters, take
them through a carwash and clean them with hot, high-pressure
water. Dry boats and trailers in the sun for two to four
days before taking them to new areas.
Running boats frequently helps reduce zebra mussel infestation.
Small juvenile mussels are soft and are scoured off the
hull at high speeds. If possible, avoid leaving outboard
motors or the drive units of inboard motors in the water
when not in use. Hulls and drive units should be inspected
periodically and scraped free of mussels. Pumping hot
water through engine intakes prevents zebra mussel growth
in the cooling system.
Zebra mussel sightings should be reported to the nearest
Conservation Department office. You can find information
about what to look for in the "Summary of Missouri
Fishing Regulations," available wherever fishing
permits are sold, or request "Zebra Mussels: Missouri's
Most Unwanted" from Conservation Department Distribution
Center, P.O. Box 180, Jefferson City, Mo., 65102-0180,
phone (573) 522-4115, ext. 3630, firstname.lastname@example.org.
The information is available online at www.mdc.mo.gov/nathis/exotic/zebra/.