I have found a few resources for you, which talk about the problem and
method of control, and do mention the effectiveness of manual removal.
Zebra Mussel Information System
Case Study : Zebra Mussel (US Government website)
However, I noticed that both of these publications were dated back in
the 90's, so I did a search through the Latest news and found that the
spread of these creatures is far from being controlled by any method.
Latest News Link -- Google News
There was a promising page from the MNT's website, stating that they
had developed and tested a repellent for the Control of Zebra Mussles.
NMT's Repellent Shown to Control Zebra Mussles
Again however I found the date back in Sept. 28, 1998. The article
sounded very promising however, so I called them. While I was not able
to talk to the inventor, his assistant told me that the product worked
very well, but they were still having problems getting a Patient for
the process, so they were not in production. He was however very
available to answering questions about what you could do in the mean
time. Even gave me his email address, which I won't post here, because
it is unnecessary ... there is a 1800 number you can call and get in
touch with him yourself if you wish to follow up.
The draw backs to manual scrapping is eventually you have to start
thinking about the disposal of the shells and mussels. Just scrapping
them off piers and docks so that they attach to the sand and rocks
bellow isn't going to be very effective for very long. The creatures
need to be removed from the water source and disposed of. Sitting in a
can for a week waiting for the trash man is probably not going to be a
viable answer either, as it takes a good two weeks for them to die
outside of the water, and the smell is reported to be amazingly bad.
The smell and waist from burning is going to be horrible as well.
I went through a very long list from the Louisiana Sea Grant College Program
and found very little after 2003. Though that link has some very
interesting articles and a RealPlayer movie about the Lessons Learned
about Control from the Great Lakes (which I watched), there was very
little about solutions and a great deal about prevention.
A recent news article talked about the infestations in Wisconsin, and
the problems expected there :
---"They will cover all the rocks, plants and shore, and when they
die, they stink," said Alexander Karatayev, a Belarusian biology
professor in Madison studying Wisconsin lakes to monitor the march of
---How are these mussels being controlled?
"After years of infestation in Europe and North America, a chemical
toxicant for lake-wide control of Dreissena has not been developed
mainly because it would be deadly to other aquatic life forms.
Prechlorination has been the most common treatment for control, but if
this method is used to control both zebras and quaggas the amount of
chlorine used may reach hazardous levels (Grime, 1995). Another
alternative has been potassium permanganate, especially for drinking
water sources, even though chemical controls are not the most
environmentally sound solution. Other methods of control include:
oxygen deprivation, thermal treatment, exposure and desiccation,
radiation, manual scraping, high-pressure jetting, mechanical
filtration, removable substrates, molluscicides, ozone, antifouling
coatings, electric currents, and sonic vibration. The need to control
these mussels has led to multi-million dollar spending. Some
industries even built their intake structures and piping at depths too
low for zebra mussel colonization; however, when the quagga mussels
were discovered at lower water depths these new structures became
vulnerable to quagga colonization. Biological control so far has
proven to be ineffective in controlling Dreissena species. Predation
by migrating diving ducks, fish species, and crayfish may reduce
mussel abundance, though the effects are short-lived (Bially and
MacIsaac, 2000). Other biological controls being researched are
selectively toxic microbes and parasites that may play a role in
management of Dreissena populations (Molloy, 1998). Other prospective
approaches to controlling Dreissena populations may be to disrupt the
reproductive process, by interfering with the synchronization of
spawning by males and females in their release of gametes (Snyder et
al., 1997). Another approach would be to inhibit the planktonic
veliger from settling, since this is the most vulnerable stage in the
life cycle (Kennedy, 2002). Researchers are continuously studying
these species to learn more about their life cycle, and environmental
and physiological tolerances, with hopes of developing environmentally
safe controls that can be used to control Dreissena populations."
That paragraph above seemed to sum up just about all of the current
methods available for the control of zebra mussels at this time.
I did find another promising article, with contact information that
you can follow up with. The test was done back in 2002, so it could be
more promising than the New Mexico Pepper Paint above.
Bacterial Toxin May Control Zebra Mussel
Other links of interest
Ohio Sea Grant College Program