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PIT Tagging and White Sturgeon Assessments. Presentation to the Fish Tagging Forum of the Northwest Power and Conservation Council March 22, 2012. Topics. Overview of Sturgeon Management Areas and Projects Broad Management Questions Examples of how PIT tags are improving assessments - PowerPoint PPT Presentation
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Presentation to the Fish Tagging Forum of the Northwest Power and Conservation CouncilMarch 22, 2012
PIT Tagging and White Sturgeon Assessments
Topics
A. Overview of Sturgeon Management Areas and Projects
B. Broad Management QuestionsC. Examples of how PIT tags are improving
assessmentsD. Down sides of PIT tags for sturgeon?
Co ml u b iai
R
v e r
Sr
n ak e
Rive
C ob
l umia
R iev r
Lower M idColumbia
(FCRPS )
Upper M idColumbia(FERC PUDs)
LowerColumbia(O R & W A )
Kootenai(US FW S RT )
UpperS nake River
(FERC I PC)
UpperColumbia
(UCW S RI )
Lower S nake(FCRPS )
oe n
Ri
Ka i
ot
v e r
Wi
ml l
t te
ae
Ri
v re
3132
SturgeonManagementPlanningUnits
3
Tagged Fish by year and area Sub-Population / Reach
YearBelow Bonneville Bonneville The Dalles John Day McNary
1993 1271994 1,147 3,7391995 5,601 4671996 2,169 4,0891997 3,7991998 2,6411999 3,49120002001 3,7092002 2,7122003 6,3122004 4,7042005 5,2932006 6,9092007 4,5282008 6,3782009 2,853 7,6392010 4,626 4,0392011 3,317 5,175 273
Sum 10,796 24,648 38,484 21,069 740
B. Broad Management Questions
Are populations at risk of extinction?Are there productivity losses and lost harvest
potential due to anthropogenic threats?How have various limiting factors and threats
affected vital rates? How effective are management actions at
reducing threats?What are appropriate sustainable harvest
rates in our current environment?
6
Population Attributes needed to address Management Questions
Spawning & Rearing Conditions
Reproduction
Age-1
Eggs
Juvenile Natural Mortality & Unexplained Loss Rates
Growth Function
Predation Mortality Rates
Adult Fishing Mortality Rates
Carrying Capacity
Sub-adult
C. Examples of how PIT tags are improving assessments
Improved Abundance EstimatesMLE survival estimatesAssessing growth rate relative to traditional
methods Assessing transplant supplementation successAssessing hatchery effectivenessAssessing movements among reservoirsAssessing exploitation rate relative to harvest
number
Improved Abundance Estimates
• Short-lived external tags and marks– Limited time-period for recaptures– Petersen-like mark-recapture estimates– N=M*C/R
• Persistent PIT tag– Long time series mark-recapture estimates– Maximum Likelihood Estimator models– Live Dead encounter histories LDLDLDLDLD– Ever growing data set and improved precision over time
9
Lower Columbia River White Sturgeon
19871989
19911993
19951997
19992001
20032005
20072009
20110
50
100
150
200
250
300
Thou
sand
s
42” – 60” White Sturgeon
Kootenai Adult Sturgeon Abundance
1989 1992 1995 1998 2001 2004 2007
% m
arke
d
0
20
40
60
80
Kootenai Recapture Rates
Survival Assessments
• Catch rate based assessment of diminishing abundance through time– Catch curves and cohort analyses
• Persistent PIT tag– Long time series mark-recapture estimates– Maximum Likelihood Estimator models– Live Dead encounter histories LDLDLDLDLD– Ever growing data set and improved precision over
time
Catch Curve
Bonneville Juvenile White Sturgeon MLE Annual Survival Rates
1994-1999 1999-2003 2003-2006 2006-20090.800.820.840.860.880.900.920.940.960.981.00
Growth Assessment
Age
Leng
th
Growth Assessment
Fork Length (cm)0 20 40 60 80 100 120 140 160 180 200 220 240 260
Ann
ual G
row
th In
crem
ent (
cm/y
r)
0
2
4
6
8
10
Growth Assessment
Fork Length (cm)0 20 40 60 80 100 120 140 160 180 200 220 240 260
Ann
ual G
row
th In
crem
ent (
cm/y
r)
0
2
4
6
8
10
Growth Assessment
Examples of how PIT tags are improving assessments
Improved Abundance EstimatesMLE survival estimatesAssessing growth rate relative to traditional
methods Assessing transplant supplementation Assessing hatchery effectivenessAssessing movements among reservoirsAssessing exploitation rate relative to harvest
number
D. Down sides of PIT tags for sturgeon? Strengths | Shortcomings
• Persistent individual mark readily identified by co-managers
• Non-lethal detection • Centralized data
storage• Tiny size
• Extra gear for samplers to carry- Special tool to recognize tag
• Limited remote detections• No data volunteered by
anglers• Relatively expensive. Esp. w/o
NPCC purchase agreements• Tag placement• Historic issues with vendors
and coding
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