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{{Taxobox
Zebra Muscles Shoot up from the ocean floor and lodge themselves into shark gills then suck out blood until the shark dies
| name = zebra mussel
| image = Dreissena_polymorpha.jpg
| image_width = 250px
| image_caption = Live zebra mussels under water with shells open, animals respiring, siphons visible.
| regnum = [[Animal]]ia
| phylum = [[Mollusca]]
| classis = [[Bivalvia]]
| subclassis = [[Heterodonta]]
| ordo = [[Veneroida]]
| superfamilia = [[Dreissenoidea]]
| familia = [[Dreissenidae]]
| genus = ''[[Dreissena]]''
| species = '''''D. polymorpha'''''
| binomial = ''Dreissena polymorpha''
| binomial_authority = [[Peter Simon Pallas|Pallas]], 1771
}}
The '''zebra mussel''', ''Dreissena polymorpha'', is a [[species]] of small freshwater [[mussel]], an [[Aquatic animal|aquatic]] [[bivalve]] [[mollusc]]. This species was originally native to the lakes of southeast [[Russia]].<ref>[http://cisr.ucr.edu/quagga_zebra_mussels.html Center for Invasive Species Research: Zebra Mussels<!-- Bot generated title -->]</ref> However, it has been accidentally introduced in many other areas, and has become an [[invasive species]] in many different countries.
[[File:Zebra mussel GLERL 1.jpg|thumb|left|100px|Drawing of zebra mussel, showing the [[byssus]]]]

Although zebra mussels superficially resemble marine mussels in the family [[Mytilidae]], and like them, are attached to solid substrates with a [[byssus]]. Nonetheless, zebra mussels are not at all closely related to the mytilids; they are much more closely related to the [[Veneridae]], the genus clams.

Zebra mussels get their name from a striped pattern which is commonly seen on their shells, though not all shells bear this pattern. They are usually about the size of a fingernail, but can grow to a maximum length of nearly two inches (5&nbsp;cm).<ref>[http://nationalatlas.gov/articles/biology/a_zm.html Zebra Mussels<!-- Bot generated title -->]</ref> The shape of the shell is also somewhat variable.

Their shells can be sharp, which makes walking in lakes where they are abundant painful.

==Anatomy==
[[File:Dreissena polymorpha1.jpg|thumb|300px|Three color varieties of the shell of the zebra mussel]]
Zebra mussels are relatively small, with adults ranging from 1/4 to 1 1/2 inches long.<ref>http://www.dnr.state.mn.us/invasives/aquaticanimals/zebramussel/index.html</ref> They have tiny stripes down their shells. Zebra Mussels have a D-shaped shell. They attach to things with 'strings', [[Byssus|byssal]] threads, which come out of their [[umbo]] on the dorsal (hinged) side. Removal of the mussel is therefore difficult.

==Ecology==
[[File:Dreissena polymorpha3.jpg|thumb|right|220px|Close-up of a typical shell of a zebra mussel]]
Zebra mussels and the closely related and ecologically similar [[quagga mussel]]s are [[filter feeder|filter-feeding]] organisms. They remove particles from the water column. Some particles are consumed as [[food]], and [[feces]] are deposited on the lake floor. Non-food particles are combined with mucus and other matter and deposited on lake floors as [[pseudofeces]].

Lake floor food supplies are enriched by zebra mussels as they filter pollution out of the water. This biomass becomes available to bottom feeding species and to the fish that feed on them.
}}
</ref><ref>
{{Citation
| last =Garton
| first =D. W.
| author-link =
| last2 =Berg
| first2 =D. J.
| author2-link =
| last3 =Stoeckmann
| first3 =A. M.
| last4 =Hagg
| first4 =W. R.
| year =1993
| date =
| title =Biology of recent invertebrate invading species in the Great Lakes: The spiny water flea, Bythotrephes cederstoemi, and the zebra mussel, Dreissena polymorpha. pages 63-84
| place = Indianapolis, Indiana.
| publisher = Indiana Academy of Science.
| edition = in B. N. McKnight editor. Biological pollution: The control and impact of invasive exotic species.
| volume =
| id =
| isbn =
| url =
}}
</ref> The catch of yellow perch increased 5 fold after the introduction of zebra mussels into Lake St. Clair.<ref>
{{Citation
| last =Saggoff
| first =M.
| author-link =
| year =Accessed July 2007
| date =
| title =What’s Wrong with Exotic Species?
| place = College Park, Maryland
| publisher =Institute for Philosophy and Public Policy, Maryland School of Public Affairs
| edition =
| volume =
| id =
| isbn =
| url =http://www.puaf.umd.edu/IPPP/fall1999/exotic_species.htm
}}
</ref>
Zebra mussels attach to most [[Substrate (marine biology)|substrates]] including sand, silt, and harder substrates. Other mussel species frequently represent the most stable objects in silty substrates, and zebra mussels attach to, and often kill these mussels.{{Citation needed|date=July 2007}} This has eliminated many native mussel species from affected lakes in North America.{{Citation needed|date=July 2007}} This pattern is being repeated in Ireland where zebra mussels have eliminated the two freshwater mussels from several waterways, including some lakes along the [[River Shannon]].{{Citation needed|date=July 2007}}

===Life cycle===
The life span of a zebra mussel is four to five years.<ref>http://fl.biology.usgs.gov/Nonindigenous_Species/Zebra_mussel_FAQs/zebra_mussel_faqs.html</ref> A female zebra mussel begins to reproduce at two years of age.
In terms of reproduction, zebra mussels are among the most prolific of all animals. An adult female zebra mussel may produce between 30,000 and one million eggs per year.<ref>/nationalatlas.gov</ref> [[spawn (biology)|Spawning]] usually begins in the months from late spring to early summer by free-swimming larvae ([[veliger]]s), which are microscopic in size, thus invisible to the naked human eye. About two to five percent of zebra mussels reach adulthood.

===Predators of zebra mussels===
There are a number of natural predators of zebra mussel. Zebra mussels have high nutritional value (Walz, 1979) and are consumed in large quantities by [[crayfish]], [[waterfowl]] and in smaller quantities by [[muskrat]]s. The nutritional value changes seasonally, particularly in terms of protein and carbonate content.

Crayfish could have a significant impact on the densities of 1 to 5&nbsp;mm long zebra mussels. An adult crayfish consumes an average of nearly 105 zebra mussels every day, or about 6000 mussels in a season. Predation rates are significantly reduced at cooler water temperatures.

Several species of fish consume zebra mussels. Of these, [[roach (fish)|roach]] seems to have the most significant impact on mussel densities. In some Polish lakes the diet of the roach consists almost exclusively (~95%) of zebra mussels (Stanczykowska, 1957). Despite all this, it seems that fish do not limit the densities of zebra mussels in European lakes. [[Smallmouth bass]] are a predator in the zebra mussels' adopted North American [[Great Lakes]] [[habitat]]. {{Harvnb|Mackie et al.|1989}}

==As an invasive species==
[[File:Zebra mussel warning sign.jpg|200px|thumb|right|Sign advising boaters on how to prevent zebra mussel spread on [[Titicus Reservoir]] in [[North Salem, New York]]]]
The native distribution of the species is the [[Black Sea]] and [[Caspian Sea]] in [[Eurasia]]. Zebra mussels have become an [[invasive species]] in [[North America]], [[the British Isles]], [[Italy]], [[Spain]], and [[Sweden]].

The zebra mussel was found and described first in the Roknighani part of Russia, but then it was recognized in the Caspian Sea. In 1991 Lisický described the distribution of this species as [[Pontic]] (Black Sea) and [[Caspian Sea|Caspian]] (Caspian Sea).<ref>{{sk icon}} Lisický M. J. 1991. ''Mollusca Slovenska'' [The Slovak molluscs]. VEDA vydavateľstvo [[Slovak Academy of Sciences|Slovenskej akadémie vied]], Bratislava, 344 pp.</ref>

Grossinger reported it in [[Hungary]] in 1794. Kerney and Morton described the rapid colonization of Britain by the zebra mussel, first in [[Cambridgeshire]] in the 1820s, London in 1824, and in the [[Union Canal (Scotland)|Union Canal]] near [[Edinburgh]] in 1834.
<ref>
{{Citation
| last =Mackie
| first =G
| author-link =
| last2 =Gibbons
| first2 =W
| author2-link =
| last3 =Muncaster
| first3 =B
| last4 =Gray
| first4 =I
| year =1989
| date =
| title =The Zebra Mussel, Dreissena polymorpha: A synthesis of European Experiences and a preview for North America
| place =
| publisher = Ontario Ministry of Environment
| edition =
| volume =
| id =
| isbn =
| url =
}}
</ref>
In 1827 zebra mussels were seen in the [[Netherlands]] at [[Rotterdam]]. Canals that artificially link many European waterways facilitated their early dispersal. They were discovered in the [[Elbe river]] in [[Bohemia]], present day [[Czech Republic|The Czech Republic]], in 1893.<ref>
{{cite journal
| journal = Vesmír
| pages = 177–178
| title = Do Čech zavlečená slávka: ''Dreissena polymorpha'' Pall
| author =
| last = Blažka
| first = F.
| coauthors =
| volume = 22
| issue = 15
| month =
| year = 1893
| doi =
| url =
| language = Czech
| accessdate=
}}
</ref> Around 1920 the mussels reached Lake [[Mälaren]] in [[Sweden]].

The first Italian appearance of the organism was in northern [[Italy]] in [[Lake Garda]] in 1973;<ref>
{{cite journal
| journal = Mem Mus Civ St Nat Verona
| pages = 45–49
| title = Dreissena polymorpha (Pallas) nuovamente in Italia. (Bivalvia, Dreissenidae)
| author = Giusti F and Oppi E
| last =
| first =
| coauthors =
| volume = 20
| issue =
| month =
| year = 1973
| doi =
| url =
| language = Italian
| accessdate=
}}
</ref> in central Italy they appeared in [[Tuscany]] in 2003.<ref>
{{cite journal
| journal = Aquatic Invasions
| pages = 281–283
| title = New records of ''Dreissena polymorpha'' (Pallas, 1771) (Mollusca: Bivalvia: Dreissenidae) from Central Italy
| author = Elisabetta Lori and Simone Cianfanelli
| last =
| first =
| coauthors =
| volume = 1
| issue = 4
| month =
| year = 2006
| doi = 10.3391/ai.2006.1.4.11
| url = http://www.aquaticinvasions.ru/2006/AI_2006_1_4_Lori_Cianfanelli.pdf
| accessdate=
}}
</ref>

===North American invasion===
In the U.S. and Canada, they were first detected in the [[Great Lakes]] in 1988, in [[Lake Saint Clair (North America)|Lake St. Clair]], located between [[Detroit, Michigan]], and [[Windsor, Ontario]].<ref name="ithica"/> It is believed they were inadvertently introduced into the lakes in the [[Sailing ballast|ballast]] water of ocean-going ships traversing the [[St. Lawrence Seaway]]. Another possible often neglected mode of introduction is on anchors and chains, although this has not been proven. Since adult zebra mussels can survive out of water for several days or weeks if the temperature is low and humidity is high, chain lockers provide temporary refuge for clusters of adult mussels that could easily be released when transoceanic ships drop anchor in freshwater ports. They have become an [[Invasive species]] in North America.

From their first appearance in American waters in 1988, zebra mussels have spread to a large number of waterways, including [[Lake Simcoe]] and the [[Mississippi River|Mississippi]], [[Hudson River|Hudson]], [[St Lawrence River|St. Lawrence]], [[Ohio River|Ohio]], [[Cumberland River|Cumberland]], [[Missouri River|Missouri]], [[Tennessee River|Tennessee]], [[Colorado River|Colorado]], and [[Arkansas River|Arkansas]] Rivers. They disrupt the ecosystems by [[Monotypic taxon|monotypic]] [[colonization]], and damage harbors and waterways, ships and boats, and water treatment and power plants. Water treatment plants were initially hit hardest because the water intakes brought the microscopic free-swimming larvae directly into the facilities.

In July, 2009, The Massachusetts Department of Conservation and Recreation confirmed that zebra mussels had been found in Laurel Lake in the Berkshires, the first documented case in a Massachusetts body of water.<ref>
{{Citation
| title = 2 Mass. towns start fight against zebra mussel
| newspaper = Boston Herald
| year = 2009
| date = 2009-07-13
| url = http://www.bostonherald.com/news/regional/view/200907132_mass_towns_start_fight_against_zebra_mussel/srvc=home&position=recent }}</ref>

In September, 2009, the Minnesota Department of Natural Resources announced that live zebra mussels have been found in [[Pelican_Lake_(Minnesota)|Pelican Lake, Minnesota]]. This was the first confirmed sighting in the [[Red River Basin]], which extends across the international border into the province of Manitoba.<ref>
{{cite press release
| title = Zebra mussels found in Pelican Lake in Otter Tail County
| publisher = MN Department of Natural Resources
| year = 2009
| date = 2009-09-17
| url = http://news.dnr.state.mn.us/index.php/2009/09/17/zebra-mussels-found-in-pelican-lake-in-otter-tail-county/#more-43227
| accessdate = 2009-09-18 }}</ref>

A common inference made by scientists predicts that the zebra mussel will continue spreading passively, by ship and by pleasure craft, to more rivers in North America. Trailered boat traffic is the most likely vector for invasion into [[Western Cordillera (North America)|Western North America]]. This spread is preventable if boaters thoroughly clean and dry their boats and associated equipment before transporting them to new bodies of water. Since no North American predator or combination of predators has been shown to significantly reduce zebra mussel numbers,{{Citation needed|date=July 2007}} such spread would most likely result in permanent establishment of zebra mussels in many North American [[Waterway|waterways]].

The cost of fighting the pests at power plants and other water-consuming facilities is $500 million a year in the U.S., according to the Center for Invasive Species Research at the University of California, Riverside.<ref name="ithica"/>

==Effects of zebra mussels==
[[File:Zebra mussel infestation Ormond Lock.jpg|thumb|Zebra mussel infestation on the walls of Arthur V. Ormond Lock on the Arkansas River]]
[[File:Zebra mussel GLERL 3.jpg|thumb|right|Zebra mussel-encrusted Vector Averaging Current Meter from Lake Michigan]]
Zebra mussels are filter feeders. When in the water, they open their shells to admit [[detritus]].

Zebra mussels are a great nuisance to people. Since [[Colonization|colonization]] of the [[Great Lakes]], they have covered the undersides of docks, boats, and anchors. They have also spread into streams and rivers nationwide. In some areas they completely cover the [[Substrate (marine biology)|substrate]], sometimes covering other freshwater mussels. They can grow so densely that they block pipelines, clogging water intakes of municipal water supplies and hydroelectric companies.

Also, as their shells are very sharp, they are known for cutting people's feet, resulting in the need to wear [[water shoes]].

Zebra mussels are also believed to be the source of deadly [[Botulism|avian botulism]] poisoning that has killed tens of thousands of birds in the Great Lakes since the late 1990s.<ref>[http://wgntv.trb.com/chi-loons_15jan15,0,35059.story]</ref>

However, zebra mussels and other non-native species are credited with the increased population and size of [[smallmouth bass]] in Lake Erie <ref>[http://sports.espn.go.com/outdoors/bassmaster/news/story?page=tourn_03_north_open_NY_erie_preview Report at ESPN Sports]</ref> and [[yellow perch]] in Lake St. Clair. <ref>[http://www.puaf.umd.edu/IPPP/fall1999/exotic_species.htm Exotic species] at PUAF</ref>.
They cleanse the waters of inland lakes, resulting in increased sunlight penetration and growth of native algae at greater depths. This cleansing also increases water visibility and filters out pollutants. Each quagga and zebra mussel filters about a quart (1 litre) of water a day when confined to small tanks.<ref>{{cite web|url=http://michigantoday.umich.edu/2009/07/story.php?id=7510&tr=y&auid=5077806|title=Great Lakes: 'Amazing change'|accessdate=2009-08-06}}</ref> In lakes, their filtering effects are usually spatially restricted (near the lake bottom) due to non-homogeneous water column mixing.

Studies from the past decade found a potential link between zebra mussel filtering and the prevalence of a toxin-producing cyanobacteria ''Microcystis''. While filtering water, the mussels appear to consume the harmless algae and reject ''Microcystis'' cells. This preferential filtering activity could translate into altered phytoplankton community composition. Zebra mussels nutrient excretion may exacerbate Microcystis growth by fueling their further growth. This filtering mechanism has been demonstrated in small-scale laboratory studies but its relevance to in natural ecosystems remains unclear.

Recent research has found that zebra mussels don't attach to copper-nickel alloys, which can be used to coat intake and discharge grates, navigational buoys, boats, motors, etc., where the pests tend to congregate.<ref name="ithica">{{cite web|url=http://www.theithacajournal.com/article/20090806/SPORTS/908060331/1128/Finally++an+answer+for+zebra+mussels|title=Finally, an answer for zebra mussels|accessdate=2009-08-06}}</ref>

==See also==
* [[Quagga mussel]]

==References==
{{reflist}}

==Further references==
Minchin, D. 2003. The Zebra Mussel ''Dreissena polymopha'' (Pallas) extends its range westwards in Ireland. ''Bull. Ir. biogeog. Soc.'' '''26''': 176 - 18.

==External links==
* [http://www.invadingspecies.com InvadingSpecies.com]
* [http://nationalatlas.gov/articles/biology/a_zm.html Zebra Mussel on National Atlas]
* [[b:Cookbook:Moules Mariniere|Moules Mariniere recipe from Wikibooks]]
* [http://cars.er.usgs.gov/Nonindigenous_Species/Zebra_mussel_FAQs/Dreissena_FAQs/dreissena_faqs.html Dreissina FAQs]
* http://nationalatlas.gov/articles/biology/a_zm.html
* [http://www.100thmeridian.org 100th Meridian Initiative]
* [http://www.protectyourwaters.net U.S Federal Stop Aquatic Hitchhikers Campaign]
* [http://news.bbc.co.uk/1/hi/northern_ireland/4472298.stm BBC News: Lough Invasion Being Investigated]
* [http://sun.science.wayne.edu/~jram/zmussel.htm The Zebra Mussel Page]
* [http://www.invasivespeciesinfo.gov/aquatics/zebramussel.shtml#fed Invasive Species: Aquatic Species - Zebra Mussel (Dreissena polymorpha)]
* [http://el.erdc.usace.army.mil/zebra/ USA CoE Zebra Mussel Research Program]
* [http://www.seagrant.wisc.edu/zebramussels/ Zebra Mussel Watch]
* [http://www.umesc.usgs.gov/invasive_species/zebra_mussels.html UMESC Invasive Species - Zebra Mussels]
* [http://www.straightdope.com/columns/060922.html "What is the zebra mussel doing to Lake Michigan?"], ''The Straight Dope,'' 22 September 2006.
* [http://www.columbia.edu.itc/cerc/danoff-burg/invasion-bio/inv-spp-summ/polymorph.html ISSG]
* [http://www.ehsni.gov.uk/zebra_2.pdf Zebra mussel in N.I.]
* [http://cisr.ucr.edu/quagga_zebra_mussels.html CISR - Zebra Mussels] Center for Invasive Species Research summary on Zebra Mussels
'''Debate'''
* [http://yukna.free.fr/science/zebramussels/grandbanks.html Did the Zebra Mussel affect Atlantic Fishing?]-C.Yukna (EMSE France)
{{commons|Dreissena polymorpha|Zebra mussel}}

{{aquatic ecosystem topics}}
{{DEFAULTSORT:Zebra Mussel}}

[[Category:Dreissenidae]]
[[Category:Invasive animal species]]

[[an:Dreissena polymorpha]]
[[ca:Musclo zebrat]]
[[cs:Slávička mnohotvárná]]
[[de:Wandermuschel]]
[[es:Dreissena polymorpha]]
[[eu:Zebra-muskuilu]]
[[fr:Moule zébrée]]
[[it:Dreissena polymorpha]]
[[hu:Vándorkagyló]]
[[nl:Driehoeksmossel]]
[[pl:Racicznica zmienna]]
[[pt:Mexilhão zebra]]
[[simple:Zebra mussel]]
[[fi:Vaeltajasimpukka]]
[[sv:Vandrarmussla]]
[[uk:Тригранка]]

Revision as of 10:59, 5 May 2010

zebra mussel
Live zebra mussels under water with shells open, animals respiring, siphons visible.
Scientific classification
Kingdom:
Phylum:
Class:
Subclass:
Order:
Superfamily:
Family:
Genus:
Species:
D. polymorpha
Binomial name
Dreissena polymorpha
Pallas, 1771

The zebra mussel, Dreissena polymorpha, is a species of small freshwater mussel, an aquatic bivalve mollusc. This species was originally native to the lakes of southeast Russia.[1] However, it has been accidentally introduced in many other areas, and has become an invasive species in many different countries.

Drawing of zebra mussel, showing the byssus

Although zebra mussels superficially resemble marine mussels in the family Mytilidae, and like them, are attached to solid substrates with a byssus. Nonetheless, zebra mussels are not at all closely related to the mytilids; they are much more closely related to the Veneridae, the genus clams.

Zebra mussels get their name from a striped pattern which is commonly seen on their shells, though not all shells bear this pattern. They are usually about the size of a fingernail, but can grow to a maximum length of nearly two inches (5 cm).[2] The shape of the shell is also somewhat variable.

Their shells can be sharp, which makes walking in lakes where they are abundant painful.

Anatomy

Three color varieties of the shell of the zebra mussel

Zebra mussels are relatively small, with adults ranging from 1/4 to 1 1/2 inches long.[3] They have tiny stripes down their shells. Zebra Mussels have a D-shaped shell. They attach to things with 'strings', byssal threads, which come out of their umbo on the dorsal (hinged) side. Removal of the mussel is therefore difficult.

Ecology

Close-up of a typical shell of a zebra mussel

Zebra mussels and the closely related and ecologically similar quagga mussels are filter-feeding organisms. They remove particles from the water column. Some particles are consumed as food, and feces are deposited on the lake floor. Non-food particles are combined with mucus and other matter and deposited on lake floors as pseudofeces.

Lake floor food supplies are enriched by zebra mussels as they filter pollution out of the water. This biomass becomes available to bottom feeding species and to the fish that feed on them. }} </ref>[4] The catch of yellow perch increased 5 fold after the introduction of zebra mussels into Lake St. Clair.[5] Zebra mussels attach to most substrates including sand, silt, and harder substrates. Other mussel species frequently represent the most stable objects in silty substrates, and zebra mussels attach to, and often kill these mussels.[citation needed] This has eliminated many native mussel species from affected lakes in North America.[citation needed] This pattern is being repeated in Ireland where zebra mussels have eliminated the two freshwater mussels from several waterways, including some lakes along the River Shannon.[citation needed]

Life cycle

The life span of a zebra mussel is four to five years.[6] A female zebra mussel begins to reproduce at two years of age. In terms of reproduction, zebra mussels are among the most prolific of all animals. An adult female zebra mussel may produce between 30,000 and one million eggs per year.[7] Spawning usually begins in the months from late spring to early summer by free-swimming larvae (veligers), which are microscopic in size, thus invisible to the naked human eye. About two to five percent of zebra mussels reach adulthood.

Predators of zebra mussels

There are a number of natural predators of zebra mussel. Zebra mussels have high nutritional value (Walz, 1979) and are consumed in large quantities by crayfish, waterfowl and in smaller quantities by muskrats. The nutritional value changes seasonally, particularly in terms of protein and carbonate content.

Crayfish could have a significant impact on the densities of 1 to 5 mm long zebra mussels. An adult crayfish consumes an average of nearly 105 zebra mussels every day, or about 6000 mussels in a season. Predation rates are significantly reduced at cooler water temperatures.

Several species of fish consume zebra mussels. Of these, roach seems to have the most significant impact on mussel densities. In some Polish lakes the diet of the roach consists almost exclusively (~95%) of zebra mussels (Stanczykowska, 1957). Despite all this, it seems that fish do not limit the densities of zebra mussels in European lakes. Smallmouth bass are a predator in the zebra mussels' adopted North American Great Lakes habitat. Mackie et al. 1989

As an invasive species

Sign advising boaters on how to prevent zebra mussel spread on Titicus Reservoir in North Salem, New York

The native distribution of the species is the Black Sea and Caspian Sea in Eurasia. Zebra mussels have become an invasive species in North America, the British Isles, Italy, Spain, and Sweden.

The zebra mussel was found and described first in the Roknighani part of Russia, but then it was recognized in the Caspian Sea. In 1991 Lisický described the distribution of this species as Pontic (Black Sea) and Caspian (Caspian Sea).[8]

Grossinger reported it in Hungary in 1794. Kerney and Morton described the rapid colonization of Britain by the zebra mussel, first in Cambridgeshire in the 1820s, London in 1824, and in the Union Canal near Edinburgh in 1834. [9] In 1827 zebra mussels were seen in the Netherlands at Rotterdam. Canals that artificially link many European waterways facilitated their early dispersal. They were discovered in the Elbe river in Bohemia, present day The Czech Republic, in 1893.[10] Around 1920 the mussels reached Lake Mälaren in Sweden.

The first Italian appearance of the organism was in northern Italy in Lake Garda in 1973;[11] in central Italy they appeared in Tuscany in 2003.[12]

North American invasion

In the U.S. and Canada, they were first detected in the Great Lakes in 1988, in Lake St. Clair, located between Detroit, Michigan, and Windsor, Ontario.[13] It is believed they were inadvertently introduced into the lakes in the ballast water of ocean-going ships traversing the St. Lawrence Seaway. Another possible often neglected mode of introduction is on anchors and chains, although this has not been proven. Since adult zebra mussels can survive out of water for several days or weeks if the temperature is low and humidity is high, chain lockers provide temporary refuge for clusters of adult mussels that could easily be released when transoceanic ships drop anchor in freshwater ports. They have become an Invasive species in North America.

From their first appearance in American waters in 1988, zebra mussels have spread to a large number of waterways, including Lake Simcoe and the Mississippi, Hudson, St. Lawrence, Ohio, Cumberland, Missouri, Tennessee, Colorado, and Arkansas Rivers. They disrupt the ecosystems by monotypic colonization, and damage harbors and waterways, ships and boats, and water treatment and power plants. Water treatment plants were initially hit hardest because the water intakes brought the microscopic free-swimming larvae directly into the facilities.

In July, 2009, The Massachusetts Department of Conservation and Recreation confirmed that zebra mussels had been found in Laurel Lake in the Berkshires, the first documented case in a Massachusetts body of water.[14]

In September, 2009, the Minnesota Department of Natural Resources announced that live zebra mussels have been found in Pelican Lake, Minnesota. This was the first confirmed sighting in the Red River Basin, which extends across the international border into the province of Manitoba.[15]

A common inference made by scientists predicts that the zebra mussel will continue spreading passively, by ship and by pleasure craft, to more rivers in North America. Trailered boat traffic is the most likely vector for invasion into Western North America. This spread is preventable if boaters thoroughly clean and dry their boats and associated equipment before transporting them to new bodies of water. Since no North American predator or combination of predators has been shown to significantly reduce zebra mussel numbers,[citation needed] such spread would most likely result in permanent establishment of zebra mussels in many North American waterways.

The cost of fighting the pests at power plants and other water-consuming facilities is $500 million a year in the U.S., according to the Center for Invasive Species Research at the University of California, Riverside.[13]

Effects of zebra mussels

Zebra mussel infestation on the walls of Arthur V. Ormond Lock on the Arkansas River
Zebra mussel-encrusted Vector Averaging Current Meter from Lake Michigan

Zebra mussels are filter feeders. When in the water, they open their shells to admit detritus.

Zebra mussels are a great nuisance to people. Since colonization of the Great Lakes, they have covered the undersides of docks, boats, and anchors. They have also spread into streams and rivers nationwide. In some areas they completely cover the substrate, sometimes covering other freshwater mussels. They can grow so densely that they block pipelines, clogging water intakes of municipal water supplies and hydroelectric companies.

Also, as their shells are very sharp, they are known for cutting people's feet, resulting in the need to wear water shoes.

Zebra mussels are also believed to be the source of deadly avian botulism poisoning that has killed tens of thousands of birds in the Great Lakes since the late 1990s.[16]

However, zebra mussels and other non-native species are credited with the increased population and size of smallmouth bass in Lake Erie [17] and yellow perch in Lake St. Clair. [18]. They cleanse the waters of inland lakes, resulting in increased sunlight penetration and growth of native algae at greater depths. This cleansing also increases water visibility and filters out pollutants. Each quagga and zebra mussel filters about a quart (1 litre) of water a day when confined to small tanks.[19] In lakes, their filtering effects are usually spatially restricted (near the lake bottom) due to non-homogeneous water column mixing.

Studies from the past decade found a potential link between zebra mussel filtering and the prevalence of a toxin-producing cyanobacteria Microcystis. While filtering water, the mussels appear to consume the harmless algae and reject Microcystis cells. This preferential filtering activity could translate into altered phytoplankton community composition. Zebra mussels nutrient excretion may exacerbate Microcystis growth by fueling their further growth. This filtering mechanism has been demonstrated in small-scale laboratory studies but its relevance to in natural ecosystems remains unclear.

Recent research has found that zebra mussels don't attach to copper-nickel alloys, which can be used to coat intake and discharge grates, navigational buoys, boats, motors, etc., where the pests tend to congregate.[13]

See also

References

  1. ^ Center for Invasive Species Research: Zebra Mussels
  2. ^ Zebra Mussels
  3. ^ http://www.dnr.state.mn.us/invasives/aquaticanimals/zebramussel/index.html
  4. ^ Garton, D. W.; Berg, D. J.; Stoeckmann, A. M.; Hagg, W. R. (1993), Biology of recent invertebrate invading species in the Great Lakes: The spiny water flea, Bythotrephes cederstoemi, and the zebra mussel, Dreissena polymorpha. pages 63-84 (in B. N. McKnight editor. Biological pollution: The control and impact of invasive exotic species. ed.), Indianapolis, Indiana.: Indiana Academy of Science.
  5. ^ Saggoff, M. (Accessed July 2007), What’s Wrong with Exotic Species?, College Park, Maryland: Institute for Philosophy and Public Policy, Maryland School of Public Affairs {{citation}}: Check date values in: |year= (help)
  6. ^ http://fl.biology.usgs.gov/Nonindigenous_Species/Zebra_mussel_FAQs/zebra_mussel_faqs.html
  7. ^ /nationalatlas.gov
  8. ^ Template:Sk icon Lisický M. J. 1991. Mollusca Slovenska [The Slovak molluscs]. VEDA vydavateľstvo Slovenskej akadémie vied, Bratislava, 344 pp.
  9. ^ Mackie, G; Gibbons, W; Muncaster, B; Gray, I (1989), The Zebra Mussel, Dreissena polymorpha: A synthesis of European Experiences and a preview for North America, Ontario Ministry of Environment
  10. ^ Blažka, F. (1893). "Do Čech zavlečená slávka: Dreissena polymorpha Pall". Vesmír (in Czech). 22 (15): 177–178. {{cite journal}}: Cite has empty unknown parameters: |month= and |coauthors= (help)
  11. ^ Giusti F and Oppi E (1973). "Dreissena polymorpha (Pallas) nuovamente in Italia. (Bivalvia, Dreissenidae)". Mem Mus Civ St Nat Verona (in Italian). 20: 45–49. {{cite journal}}: Cite has empty unknown parameters: |month= and |coauthors= (help)
  12. ^ Elisabetta Lori and Simone Cianfanelli (2006). "New records of Dreissena polymorpha (Pallas, 1771) (Mollusca: Bivalvia: Dreissenidae) from Central Italy" (PDF). Aquatic Invasions. 1 (4): 281–283. doi:10.3391/ai.2006.1.4.11. {{cite journal}}: Cite has empty unknown parameters: |month= and |coauthors= (help)
  13. ^ a b c "Finally, an answer for zebra mussels". Retrieved 2009-08-06.
  14. ^ "2 Mass. towns start fight against zebra mussel", Boston Herald, 2009-07-13{{citation}}: CS1 maint: date and year (link)
  15. ^ "Zebra mussels found in Pelican Lake in Otter Tail County" (Press release). MN Department of Natural Resources. 2009-09-17. Retrieved 2009-09-18.{{cite press release}}: CS1 maint: date and year (link)
  16. ^ [1]
  17. ^ Report at ESPN Sports
  18. ^ Exotic species at PUAF
  19. ^ "Great Lakes: 'Amazing change'". Retrieved 2009-08-06.

Further references

Minchin, D. 2003. The Zebra Mussel Dreissena polymopha (Pallas) extends its range westwards in Ireland. Bull. Ir. biogeog. Soc. 26: 176 - 18.

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