10 Tips to Prevent the Spread of Zebra Mussels throughout Missouri
Zebra mussels, one of the most notorious unwanted hitchhikers, have already made their way into
the Missouri, Mississippi, and Meramec Rivers. It is up to every Missouri resident and tourist to
keep from spreading these harmful mussels throughout the rest of the state. Steve McMurray,
mussel biologists with the Resource Science Division of MDC states, “Aquatic nuisance species
such as the zebra mussel represent the next ecological and socio-economic threat facing our
natural aquatic ecosystems. While it is illegal to introduce new aquatic nuisance species into
Missouri waters, preventing the spread of zebra mussels will require vigilance from all of us,
citizens and tourists alike”.
Why are zebra mussels on the unwanted list?
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The fast multiplying zebra mussels attach and colonize on hard surfaces, such as water
intake structures used for power and municipal water treatment plants. Unprotected
docks, break walls, boat bottoms, engine outdrives, and native freshwater mussels are
also targets of zebra mussels.
Zebra mussels consume considerable amounts of beneficial microscopic organisms and
this creates less food for larval and juvenile fishes that support native fisheries and native
freshwater mussels.
Beaches are also affected by zebra mussels. The sharp-edged shells along swimming
beaches can be a hazard to unprotected feet.
The potential for zebra mussels to spread is very high. These hitchhikers can spread to
other inland waters either in their immature form known as veligers transported in water
or as adults attached to boat hulls, engines, aquatic weeds, or other surfaces. Veligers are
small, about the size of the period at the end of this sentence, and may be able to survive
in any residual water source. Adults are very hardy and can survive out of water for
extended periods depending upon temperature, humidity, wind, and sunlight. Maximum
out-of-water survival time in ideal conditions is about 10 days for adults and 3 days for
newly-settled juveniles.
Originally brought to North American waters in international shipping ballast water and
discovered in Lake St. Clair near Detroit in 1988, zebra mussels have spread rapidly
throughout the Great Lakes and connected waterways.
Female zebra mussels can produce as many as one million eggs per year.
The negative economic impacts of zebra mussels in North America during the next
decade are expected to be in the billions of dollars.
What can you do to Stop this Aquatic Hitchhiker? The following are 10 tips to help protect your
pocket book and Missouri waters.
1. Inspect. Thoroughly inspect your boat’s hull, drive unit, trim plates, trolling plates, prop
guards, transducers, anchor, anchor rope and your trailers centerboards, axles and rollers.
2. Remove. Remove any visible zebra mussels, however small. If zebra mussels are found,
scrape off and trash suspected individuals. Also remove weeds and mud, even the
smallest of amounts.
3. Properly Dispose. Left over bait or any thing unwanted items removed from the boat
should be properly disposed of in the trash and not thrown back into the waters.
4. Drain. While on land and before leaving any body of water, drain water from all parts of
your boat and equipment such as the motor, live well, bilge, transom wells, and bait
buckets.
5. Clean. Thoroughly rinse your boat, trailer and equipment. If you were in known zebra
mussel infested waters, use 104 F hot water and/or use the high pressure hot water from
do-it-yourself car washes to “de-zebra” your boat.
6. Dry. All parts of the boat should be dry before entering another body of water. If you
were in known infested waters, boats, motors and trailers should be allowed to dry
thoroughly in the hot sun for at least five days before boating in another body of water.
7. Run. If your boat is kept in infested waters, the best way to keep a hull zebra mussel-free
is to run the boat frequently. Juvenile zebra mussels are quite soft and are scoured off the
hull at high speeds.
8. Up/Pump. When in zebra mussel infested waters, leave outboards or outdrives in the up
position and pump hot water through your engine’s intake on a regular basis to prevent
growth inside the engine’s cooling system.
9. Identify the enemy. Learn what these organisms look like (at least those you can see). If
you suspect any new infestations of an exotic plant or animal, report it to the Missouri
Department of Conservation.
10. Pass the word. If you know people who recreate on Missouri waters (particularly those
who boat in out of state waters or in the big rivers of Missouri), talk to them about the
importance of following these procedures to protect your waters.
For more information on stopping aquatic hitchhikers, go to www.protectyourwaters.net or
contact the Missouri Department of Conservation.