Use of Landscape Ecology to Analyze the Control of an Invasive,
the Zebra Mussel
Hayley Tumas
usgs.gov
Goals
• Impart knowledge on the severity of the zebra mussel problem
• Use the principles of landscape ecology to examine the population dynamics of zebra mussels in the United States
• Use my results to create methods for eradication and as a baseline for other invasives
Zebra Mussel (Dreissena polymorpha)
• Freshwater mollusk
• Native to Eurasia
• Range from 1/4in-2 in
• Long-lived
• Active filter feeder
• Female produces 30,000 to 1 million eggs per year beginning at 2 years of age
• Planktotrophic larvae
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Invasive Species • Invaded the Great Lakes
between 1986-1988
• Found in Hudson River and St. Lawrence River by 1991
• Rapid dispersal mainly due to larval characteristics
– Dependent on current or wind advection
– Metapopulation dynamics
• Human-mediated long distance dispersal
1986
1996
2010 nationalatlas.gov
Ecological Threat • Alter food webs
• convert soft benthic habitats to hard substrate
• Bioamplify contaminants
• Outcompete native bivalves, fish, and water fowl
• Attach to any slow-moving or sessile animals
• Substantially decrease dissolved oxygen
MD DNR
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Economic Costs
• Projected cost of $4 billion in the first decade
• Collapse of sport fisheries and native bivalve industry
• Attach to boats, navigational buoys, and water intake pipes
• Hazardous to recreational beaches
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Motivation
• To date, all research efforts, public outreach, and policy have failed
– Scientists avoid difficult or expensive analyses
– Public does not understand severity of problem
– Many exceptions to current policy
• Need a better method for dealing with invasives
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Objective
• Examine geographic and genetic data on the zebra mussel to determine the population dynamics at a landscape level. Use landscape ecology to help develop methods for eradication
• Specifically focus on the Great Lakes region
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Landscape Ecology
• “study of how spatial pattern affects ecological processes” (With, 2002)
• Recognizes patchiness of habitat spatially and temporally
• Examines a level above communities and ecosystems, below biomes
• Anthropocentric approach
ESA
Graph Theory
Dispersal Distance: 100 M Dispersal Distance: 150 M
Node
Methods 1) Plot the nodes
– Find the geographical points for each existing population in the Great Lakes and surrounding area
– Use ArcGIS to analyze the spatial configuration
2) Determine dispersal relationships between nodes
– Derived from a paternal analysis of larvae though genetic sampling
3) Analyze the population dynamics at the landscape level
– Examine the landscape connectivity and other landscape metrics using ArcGIS and CONEFOR
www.matrixgreen.org
Results I will determine:
• the nodes most important for dispersal and persistence
• the dispersal distance of the populations in the area
• which populations are connected
…which can be used to: • decide on which populations to focus control efforts
on
• pick useful places for dams or other obstructions of flow/dispersal
• choose focus points for policy regulating commercial and recreational boating practices
Broader Impacts
• Control and potential eradication of zebra mussels in the Great Lakes
– Ecological and economic impacts
• Control of zebra mussels in the rest of the United States, Canada, and Europe
• Further current knowledge of invasive species dynamics
• Create an initial set of methods for landscape analysis and control of invasive species
Questions?
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References 1. Johnson, L.E. and J.T. Carlton. 1996. Post-establishment spread in large scale invasions: dispersal
mechanisms of the zebra mussel (Dreissena polymorpha). Ecology 77:1686-1690. 2. Moody, M.E. and R.N. Mack. 1988. Controlling the spread of plant invasions: the importance of
nascent foci. Journal of Applied Ecology 25: 1009-1021. 3. Strayer, D.L and H.M. Malcom. 2006. Long-term demography of a zebra mussel (Dreissena
polymorpha) population. Freshwater Biology 51: 117-130 4. Stepien C.A., C.D. Taylor, K.A. Dabrowska. 2002. Genetic variability and phylogeographical
patterns of a nonindigenous species invasion: a comparison of exotic vs. native zebra and quagga mussel populations. Journal of Evolutionary Biology 15: 314-328.
5. With, K.A. 2002. The landscape ecology of invasive spread. Conservation Biology 16:1192-1203. 6. Strayer, David L. 2009. Twenty years of zebra mussels: lessons from the mollusk that made
headlines. Ecological Society of America 7: 135-141. 7. Stoeckel, J.A., D.W. Schneider, L.A. Soeken, D. Blodgett, R.E. Sparks. 1997. Larval dynamics of a
riverine metapopulation: implications for zebra mussel recruitment, dispersal, and control in a large river system. Journal of North American Benthological Society 16: 586-601.
8. Griffiths, R.W., D.W. Schloesser, J.H. Leach, W.P. Kovalak. 1991. Distribution and dispersal of the zebra mussel (Dreissena polymorpha) in the Great Lakes region. Can. J. Fish. Aquat. Sci. 48:1381-1388.
9. Urban, D. and T. Keitt. 2001. Landscape connectivity: a graph-theoretic perspective. Ecology 82:1205-1218
10. Sork, V.L. and P.M. Smouse. 2006. Genetic analysis of landscape connectivity in tree populations. Landscape Ecology 21:821-836.
11. Baguette, M. and H. Van Dyck. 2007. Landscape connectivity and animal behavior: functional grain as a key for determinant dispersal. Landscape Ecology 22:1117-1129.
12. Neel, M. C., K. McGarigal, S.A. Cushman.2004.Behavior of class-level landscape metrics across gradients of class aggregation and area.Landscape Ecology 19:435-455.