pattern of spread of zebra mussels in minnesota · michael mccartney’s talk after the break!...
TRANSCRIPT
Pattern of spread of zebra mussels in Minnesota
Sophie Mallez & Michael [email protected]/[email protected]
October 17th, 2016
The zebra mussel invasion
• Native to the Ponto-Caspian region
• Introduced in Europe (1800) and North America (1985)
• Introduced in Minnesota in 1989• Spread through the Mississippi and St Croix rivers• First inland lake infested in 2003• New infestations occurred yearly but < 2 % lakes infested
The zebra mussel invasion
• Native to the Ponto-Caspian region
• Introduced in Europe (1800) and North America (1985)
• Introduced in Minnesota in 1989• Spread through the Mississippi and St Croix rivers• First inland lake infested in 2003• New infestations occurred yearly but < 2 % lakes infested
Great benefits of targeted prevention
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Dispersal
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Dispersal
DiffusionStepping-stone
Long-distance dispersal
Stratified dispersal
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Dispersal
DiffusionStepping-stone
Long-distance dispersal
Stratified dispersal
Important mechanism for zebra mussel spread
Overland
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Dispersal
DiffusionStepping-stone
Long-distance dispersal
Stratified dispersal
Small spatial scales?
Multiple independent events of introduction from distant lakes or local spread from infested lakes nearby?
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Dispersal
DiffusionStepping-stone
Long-distance dispersal
Stratified dispersal
Small spatial scales?
Identifying the vectors involvedWhat to target for limiting the spread?
Pattern of spread – Key step
Preventing = Understanding the pattern of spread
Dispersal
DiffusionStepping-stone
Long-distance dispersal
Stratified dispersal
Study of clustered invasions
Small spatial scales?
Samples & Tools
• Sampling throughout Minnesota mostly• 59 sites - 35 water bodies – 1747 individuals
Samples & Tools
• Sampling throughout Minnesota mostly• 59 sites - 35 water bodies – 1747 individuals
Samples & Tools
• Sampling throughout Minnesota mostly• 59 sites - 35 water bodies – 1747 individuals
• Genotyping of 9 microsatellite markers• Obtained from the literature • Optimized for this study
Samples & Tools
• Sampling throughout Minnesota mostly• 59 sites - 35 water bodies – 1747 individuals
• Genotyping of 9 microsatellite markers• Obtained from the literature • Optimized for this study
• Population genetics analyses• Analysis of diversity• Analysis of genetic structure/clustering• Approximate Bayesian Computation
Analysis of genetic diversity
Analysis of genetic diversity
*Mille Lacs Lake Prior Lake 8 lakes in Alexandria area
Moderate founder effects due to bottlenecks
Analysis of genetic diversity
Broad pattern:Large number of mussels and/or larvae cause infestations
Moderate founder effects due to bottlenecks
Analysis of genetic structure/clustering
Well-defined clusters distinguish important lake infestations
K = 2
K = 3
K = 4
K = 5
K = 6
K = 7
K = 8
Mille Lacs Prior Alexandria area Brainerd area
Analysis of genetic structure/clustering
Prior Lake
Mille Lacs Lake
Analysis of genetic structure/clustering
Prior Lake
Mille Lacs Lake
Analysis of genetic structure/clustering
Michael McCartney’s talk after the break!
Analysis of genetic structure/clustering
Brainerd-area lakes
+ Mississippi River
Analysis of genetic structure/clustering
Brainerd-area lakes
+ Mississippi River
K = 1
K = 2
K = 3
K = 4
Analysis of genetic structure/clustering
Brainerd-area lakes
+ Mississippi River
K = 1
K = 2
K = 3
K = 4
Local spread = the main process
occurring in this area
Alexandria-area lakes
Analysis of genetic structure/clustering
Alexandria-area lakes
Analysis of genetic structure/clustering
Alexandria-area lakes
Analysis of genetic structure/clustering
Analysis of genetic structure/clustering
Alexandria-area lakes
Infested lake
Analysis of genetic structure/clustering
Alexandria-area lakes
Approximate Bayesian Computation
CarlosIrene
Darling
Mary
Analysis of invasion models
• Approximate Bayesian Computation• Comparison of scenarios of invasion• Selection of the most likely one based on probabilities
Analysis of invasion models
• Approximate Bayesian Computation• Comparison of scenarios of invasion• Selection of the most likely one based on probabilities
Carlos IreneDarling Mary2009 20112010 2013
Carlos Darling
Carlos Darling
Analysis of invasion models
• Approximate Bayesian Computation• Comparison of scenarios of invasion• Selection of the most likely one based on probabilities
Carlos Irene
Irene independent
Darling Irene
Carlos IreneDarling Mary2009 20112010 2013
Carlos Darling
Carlos Darling
Analysis of invasion models
• Approximate Bayesian Computation• Comparison of scenarios of invasion• Selection of the most likely one based on probabilities
Carlos
Mary independent
MaryDarlingIrene
Carlos
Darling
Irene
Irene MaryMary
Carlos IreneDarling Mary2009 20112010 2013
Carlos Darling
Carlos Darling
Irene independent
Analysis of invasion models
• Approximate Bayesian Computation• Comparison of scenarios of invasion• Selection of the most likely one based on probabilities
Carlos
Mary independent
MaryDarlingIrene
Carlos
Darling
Irene
Irene MaryMary
Carlos IreneDarling Mary2009 20112010 2013
Carlos Darling
Carlos Darling
Irene independent
24 scenarios to compare!
DarlingMary
Carlos
Irene
Analysis of invasion models
Scenario with the highest probability
Prob. = 52 %Carlos
Darling independent
Mary independent
Irene
DarlingMary
Carlos
Irene
Analysis of invasion models
Scenario with the highest probability
Local spread – Stepping-stone pattern
Carlos Irene
Prob. = 52 %
Darling independent
Mary independent
DarlingMary
Carlos
Irene
Analysis of invasion models
Scenario with the highest probability
Independent events of introduction
Carlos Irene
Prob. = 52 %
Darling independent
Mary independent
Results summary
• High genetic diversity: Infestations are founded by many individuals
• If veligers in residual water are the vector—multiple introductions• Vectors that transmit juveniles or adults—docks, lifts, resident
boats—can introduce large #s of mussels per transport event
Results summary
• High genetic diversity: Infestations are founded by many individuals
• If veligers in residual water are the vector—multiple introductions• Vectors that transmit juveniles or adults—docks, lifts, resident
boats—can introduce large #s of mussels per transport event
• Clustered invasion• Local spread = predominant at small spatial scales
Brainerd area
Alexandria areaLocal spread + Independent
events of introduction
Different vectors involved?Boats vs. Lifts, docks…
• UMN: Grace Van Susteren, Sarah Peterson, Maxwell Kleinhausand Melody Truong for sampling and lab support
• NPS: Byron Karns and Michelle Prosser for field/sampling support and advice
• MnDNR: Daniel Swanson and Richard Rezanka for field/sampling support and advice
• Clear Water Fund, ENRTF for funding
For more information on MAISRC, please visit:http://www.maisrc.umn.edu
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