Lake sturgeon Acipenser fulvescens restoration is a priority throughout the Great Lakes basin, where sturgeon have been reduced to less than 1% of historic levels due to habitat degradation, overharvest, and fragmentation of spawning populations. The population parameters most

important to long-term lake sturgeon persistence are unknown

Hayes, Daniel B.

Schueller, Amy M.

Aquatic Commons

Sensitivity of lake sturgeon population dynamics and genetics to demographic parameters
Amy M. Schueller and Daniel B. Hayes
Department of Fisheries and Wildlife, Michigan State University
Acknowledgments
This research was supported by the Great Lakes Fishery Trust Fund, Michigan Department of 
Natural Resources, and Michigan State University.
Conclusions
 Adult mortality was the most sensitive.  Reducing the adult mortality of 
lake sturgeon will thus have the largest impact on population 
persistence, gene retention, and inbreeding. 
 Juvenile mortality, adult mortality, age at first maturation for females, and 
the probability of mating for females were hypersensitive parameters.
 The probability of mating for males and the age at first maturation for 
males were insensitive parameters.  
Introduction
Lake sturgeon Acipenser fulvescens restoration is a priority throughout 
the Great Lakes basin, where sturgeon have been reduced to less than 
1% of historic levels due to habitat degradation, overharvest, and 
fragmentation of spawning populations.  The population parameters most 
important to long-term lake sturgeon persistence are unknown.
Methods
 An individual-based model that represented demographics and 
genetics was developed where age, sex, and genetic makeup of each 
individual in the population was tracked
 Model included age specific mortality rates and represented a 
polygamous mating system
 Genes followed Mendelian modes of inheritance
 Inbreeding, fx, was calculated via path analysis:
 Model parameters were estimated from the literature and empirical 
data
 Parameters were perturbed across a range of plausible values
 Recorded rate of extinction, average inbreeding coefficient, and
percentage of alleles lost
 Sensitivity (S) was expressed as the percent difference in the output 
when the parameter was changed, compared to the value when all of 
the parameters are set at their mean:
Management Implications
 Management options are available for reducing both juvenile and adult 
mortality rates.  Stocking, stream-side rearing, reduced harvest, and 
protection from poaching during the spawning season could all lead to 
reduced mortality rates for sturgeon and will help foster the sustainability 
of lake sturgeon for the future.
Objective
To determine which population parameters for lake sturgeon have the 
greatest influence upon the rates of extinction, average inbreeding 
coefficients, and percentage of alleles lost in a 250 year simulation.
-12
-10
-8
-6
-4
-2
0
2
4
6
-0.6 -0.4 -0.2 0 0.2 0.4
S
e
n
s
i
t
i
v
i
t
y
 
Juvenile mortality
Adult mortality
Age of female maturation
Female mating prob.
Age of male maturation
Male mating prob.
Figure 1. Percent change in parameter versus sensitivity for average 
percent of genes retained for lake sturgeon.
-20
-15
-10
-5
0
5
10
15
-0.6 -0.4 -0.2 0 0.2 0.4
S
e
n
s
i
t
i
v
i
t
y
 
 
 
 
Juvenile mortality
Adult mortality
Age of female maturation
Female mating prob.
Age of male maturation
Male mating prob.
Figure 2. Percent change in parameter versus sensitivity for percent of 
increasing populations for lake sturgeon.
-10
-5
0
5
10
15
20
-0.6 -0.4 -0.2 0 0.2 0.4
S
e
n
s
i
t
i
v
i
t
y
 
 
 
 
 
 
Juvenile mortality
Adult mortality
Age of female maturation
Female mating prob.
Age of male maturation
Male mating prob.
Figure 3. Percent change in parameter versus sensitivity for final mean 
inbreeding for lake sturgeon.
( )A
nP
i
x ff +⎥⎦
⎤⎢⎣
⎡=∑
−
1
2
1
1
nna
nna
PPP
RRRS
/)(
/)(
−
−=
Contact info:  Amy Schueller
schuel11@msu.edu
517-353-6697


Sensitivity of Lake Sturgeon population dynamics and genetics to demographic parameters [Powerpoint Slide]

http://aquaticcommons.org/14801/1/aschueller-AFSposter-2007.pdf

Sensitivity of Lake Sturgeon population dynamics and genetics to demographic parameters [Powerpoint Slide]

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