Transcript Slide 1

Impact of Zebra Mussels
as an Invasive Species
By: Melissa Malmstedt
Background on Zebra Mussels
• Dreissena polymorpha
• Common name: Zebra Mussel
• Originally from Caspian Sea and Ural
River
• Also native to the Balkans, Poland, and
the former Soviet Union
Occurrences of Zebra mussels in
non native areas
• Late 18th century – early 19th century spread
throughout most of Europe
• May have arrived in North America via a
European ship's ballast water.
• 1988 came from Canada’s Lake St. Clair into
lake Huron and Lake Erie.
• 1990 populations in all of the Great Lakes.
• 1991 found in Hudson and Illinois rivers.
• 1992 found in Mississippi, Arkansas, Ohio,
and Tennessee rivers.
Biology of Zebra Mussels
•
•
•
•
Fresh water mollusks
Bivalve
Colonial
Filter feeders
– Inhalant and exhalant siphons
– Feed on algae
Ecology of Zebra Mussels
• Optimal pH is between 7.4 and 8.5
• High oxygen between 8-10 parts per
thousand
• Temperatures between 17 and 25
degrees C.
• Impact many species.
– Unionids
– Decreased zooplankton
Ecology cont.
• Increase water clarity
– Increase in light
– Increase of macrophytes and macrophyte
beds that serve nurseries for fish
• Prefer to attach to live unionids
Reproduction
• Females begin to reproduce around 2
years of age
• Broadcast spawning triggered by:
– Chemicals produced by algae
– Temperature around 14-16 degrees C
• Can produce 40,000 eggs in a single
reproductive cycle
Reproduction cont.
• 3 periods of life
– Larval
– Juvenile
– Adult
• Larvae; planktonic during trochophore, straight
hinged veliger, and umbonal veliger stages.
Pediveliger stage (settlement takes place) is the
final larval form.
Reproduction cont.
• Planligrade; stage between larval and
juvenile periods.
• Juvenile
– Development of fertilized egg to juvenile can
take anywhere from 8-240 days.
– Change in morphology
• Adult
– Considered an adult when sexual maturity is
reached.
Settlement on Zebra
mussel (Pediveliger
stage)
Impact of Colonizing Zebra
Mussels on Humans
• Clog pipes
• Hydroelectric and nuclear power plants
• Public water supply
• Other industrial facilities
Clogged pipe
Control of Zebra Mussels
• Chemical
– Oxidizing
• Chlorination
– Toxic pipes
• Copper, brass, and galvanized metals are toxic to zebra
mussels.
• Biological
– Bacteria
– Predation
• Ducks
• Fish
Refrences
Ackerman, J.D., Sim, B., Nichols, S.J., and Claudi, R.
(1994). “A
review of the early life history of zebra
mussels (Dreissena
polymorpha): Comparisons with marine bivalves.” Can. J. Zool. 72:11691179.
Genthnera, F., Winsteada, J., Gilleta, J., Van, A. Vielb,
J.,
Genoveseb, E., Singerb, S. (1997) “Effects of a molluscicidal Strain of
bacillus alveion on digestive tubules of zebra mussels, Dreissena
polymorpha”
Journal of Invertabrate Pathology. 69: 289-291.
Jack, J.D., Thorp, J.H. (2000). “ Effects of benthic
suspension feeder Dreissena polymorpha on zooplankton
in a
large river.” Freshwater Biology. 44:569-579.
MacIsaac, H.J. (1996). “Potential abiotic and biotic
impacts of
zebra mussels on the inland waters of North
America,” Am. Zool. 36:
87-299
Rajagopal, S., Velde, G., Jenner, H. (2002) “Effects of
low-level chlorination on zebra mussel, Dreissena
polymorpha”
Water Research. 36: 3029-3034.
Schloesser, D.W., Nakepa, T.F., Mackie, G.L.(1996) “Zebra
mussel
infestation of unionid bivalves (Unionidae) in North America.” Amer.
Zool. 36:300-310.
Tucker, J.K. (1994)”Colonization of unionid bivalves by the zebra mussel,
Dreissena polymorpha,in pool 26 of the Mississippi River.” J.
Freshwater Ecol. 9:129-134.
----,Zebra Mussel Information System, U.S. Army Corps of Engineers