Using uncertainty analysis to provide sampling guidance in monitoring fish and loons for mercury pollution

1. Using uncertainty analysis to provide
sampling guidance in monitoring fish and
loons for mercury pollution
Yang Yang1*, Ruth Yanai1, Charley Driscoll2,
Geoffrey Miller2, Nina Schoch3, David Evers4
State University of New York-ESF1, Syracuse University2
Adirondack Center for Loon Conservation3,
Biodiversity Research Institute4

2. https://www.google.com/search?q=no+fishing+mercury+sign&rlz=1C1CHZL_enU
S732US732&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiEsaDBxqjaAhUCsl
MKHflQDtQQ_AUICygC&biw=1366&bih=662#imgrc=DF16_FEyaNFOQM:

3. Adirondack Fish Monitoring Program
1992-2016
106 lakes
Long-term
Resurveyed
43 lakes 2000s vs. 2010s

4. Adirondack Loon Monitoring Program
111 lakes
from 1998 to current
https://www.google.com/search?rlz
&q=loon&oq=loon&gs_l=
https://www.google.com/search

5. Calculation of minimum detectable changes
Minimum detectable change (MDC):
A statistical estimate of the smallest amount of change that
can be significantly detected
EPA Technical Memorandum #3

6. Calculation of minimum detectable changes
A. Detecting a change between two points of a time
Two sample t-test
Paired t-test
B. Detecting changes over a time series
43 resurveyed lakes in 2000s vs. 2010s
111 lakes from 1998 to 2016

7. MDCs using paired/two sample t-test
N = sample size
S2 = pooled variance
Z = standard normal probabilities
Objectives: how many lakes do we need?
Resurveyed
43 lakes 2000s vs. 2010s

8. MDCs varied by species

9. Changes over time
N = number of years
CV = temporal variation
T = the test statistic of the T-test
Objectives: how many lakes per year and how many years?
111 lakes from 1998 to 2016
a. for 5-25 lakes and 5-20 years
Resampling from 886 observations
CV = temporal variation
b. with 5000 iterations

11. Other methods of uncertainty analysis
Statistical programsPower analysis
‘fishmethods’ package (Nelson 2015) in R
Green, P., and MacLeod, C. J. 2016.
SIMR: an R package for power
analysis of generalized linear mixed
models by simulation. Methods in
Ecology and Evolution. 7: 493-498
Fitting GLM model
Setting a changing rate
Adjusting sample size

12. Acknowledgement
Field and laboratory work
Financial support
The Wild Center
The Raquette River Advisory Council
And more and more…