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What Are Zebra Mussels and Where Do They
Come From
Invasive species are species that are introduced to a new environment where there are no natural predators. If that species
can survive in the new habitat, they will take over and potentially harm that environment severely. The zebra mussel is an
example of an invasive species. Zebra mussels (Dreissena polymorpha) are about the size of a finger nail that reproduce
in vast numbers and filter feeds on phytoplankton. This species is native to the Caspian Sea region of Asia (Manninen, 2006)
and were transported to North America via ballast water from European waterways (Conroy, Culver, 2005). They were discovered
in 1988 in Lake St. Clair and have since traveled to all the Great Lakes and waterways in many states including some waterways
in Canada.
Their range of expansion has had major effects both ecologically and economically. Due to their prolific and invasive nature,
the biodiversity of North American waterways is being threatened(Drake,Bossenbroek, 2004).
Invasive and Prolific Zebra Mussels
Zebra mussels are invasive and prolific due to their ability to adhere in large numbers to any hard surface and the amount
of larvae they release after reproduction. They're also prolific filter feeders that have no natural predators in the Great
Lakes region. They are also filling a niche in this area (hard substrate) (Ludyankskiy, McDonald, 1993). Because of their
ability to filter vast amounts of phytoplankton from the water and their large unchecked numbers, many small fish species
are deprived of their means of nutrition(Ludyankskiy, McDonald, 1993). This is having a domino effect on the Great Lakes
fisheries. As the population of smaller fish is reduced, the number of larger predator fish is reduced in kind. This in
turn makes the Great Lakes fisheries susceptible to collapse or disaster should some disease infiltrate the system (Beekey,
McCabe, Marsden, 2004). The Great Lakes fisheries are a large source of food and income for people living in the area. Unless
ways are found to keep zebra mussels in check, human beings in the effected area are going to have to deal with their economic
and environmental impact for the foreseeable future (Ludyankskiy, McDonald, 1993).
The Effect on Humans and How to Control
The zebra mussel has attributes that make it not only a concern for aquatic life, but human life as well. The zebra mussel's
specialty is the ability to filter feed large amounts of water. By feeding this way, this mussel not only clears up polluted
water (Ludyanskiy, McDonald, 1993) "but removes even larger amounts of phytoplankton and detritus from the water"(Ludyanskiy,
McDonald, 1993). According to Ludyanskiy and McDonald, "zebra mussels remove large percentages of primary productivity which
may reduce the energy available to pelagic food webs. They also suggest that fish recruitment and growth may also be affected"(Ludyanskiy,
McDonald, 1993). When the zebra mussel feeds and cleans the water, it deposits these contaminants by way of waste,or "pseudo
feces,which is mucous combined with the contaminants" (Gulf of Maine Aquarium, 2005), that the other aquatic life eat and
then distributes among other species. The mussels not only affect humans by washing up on the shore and cutting feet (Gulf
of Maine Aquarium, 2005), but also fouls trash tracks, bar racks, culverts, waterways, raw wells, screen house walls, traveling
and stationary screens, inlet pumping tubes, strainers, inlet condenser water boxes and settling tanks(Ludyanskiy, McDonald,
1993). An even bigger effect, though, is that the mussel clusters block intake pipes, mainly of factories (Ludyanskiy, McDonald,
1993). To remove these clusters costs millions of dollars. The U.S. and Wildlife Service has said that the cost of industrial,
utility, and municipal- water- use reductions due to bio fouling, plus the impact of the zebra mussel on navigation boating
and sport fishing could reach 5 billion by the year 2000 in the Great Lakes alone" (Ludyanskiy, McDonald, 1993). To control
these invasive creatures, many different strategies have been theorized and tested. Some of these strategies range from chemical
to biological.
Some areas in North American have been testing "microorganisms in nature that could be selectively toxic" to the zebra
mussel. But most of the chemicals used for the eradication of the zebra mussel today do not selectively kill and take out
other natural species (Ludyanskiy, McDonald, 1993).
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Refrences
Beekey, M.A., Marsden, J.E. "Zebra Mussels Affect Benthic Predator
Foraging Success and Habitat Choice on Soft Sediments." Behavioral Ecology. 1 October 2003: 2004.
Conroy, Joseph D., Culver, David A. "Do Dreissenid Mussels
Affect Lake Erie Ecosystem Stability Process?" The American Midland Naturalist 1st ser. 153 (2005): 20-32.
Drake, John M., Bossenbroek, Jonathan M. "The Potential Distribution
of Zebra Mussels in the United States." BioScience 54 (2004): 931-941.
Ludyanskiy, Michael L., McDonald, Derek. "Impact of
the Zebra Mussel, A Bivalve Invader." Bioscience 43.8 (1993): 1-19.
Manninen, Christine. "Zebra Mussels in the Great
Lakes Region." GLIN. 1993. 4 January 2006 <http://www.great-lakes.net/envt/flora-fauna/invasive/zebra.html>
"Zebra Mussels." Gulf of Maine
Aquarium. 8 December 2005: <http://octopus.gma.org/surfing/human/zebra.html>
Links
This site gives information about other invasive species as well as additional links to
information about zebra mussels
Zebra Mussels in the Great Lake Region
This site gives the origin of the zebra mussel as well as other information on the Great Lakes
An overview of how zebra mussels effect commercial vessels on inland waterways details on where and
how they live
The pros and cons of mussels in America
An article that gives information about what to watch for and how to determine if a lake contains
the zebra mussels.
An article from the Detroit news that discusses the problems in the Great Lakes caused by foreign
species including zebra mussels and gives an idea about controlling them
This site gives a fact sheet zebra mussels, FAQ's and distribution information
A site that discusses the invasion in North America, the biology and the impact of zebra mussels.
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