Natural Reproductive Success and Demographic Effects of Hatchery-Origin
Steelhead in Abernathy Creek, Washington
Abernathy Fish Technology CenterU.S. Fish and Wildlife Service
Traditional Hatchery Procedures
An Alternative
• Collect & rear natural-origin juveniles to sexual maturity
1) Large #s of fish & low effect on population
2) High Genetic Diversity
Objectives
1) Assess the overall effects of hatchery supplementation relative to control streams
2) Determine the natural reproductive success of hatchery-origin and natural-origin steelhead
Comprehensive Approach
Hatchery Management & Procedures
Cost/Benefit Analysis
Direct application to hatcheries with
conservation goals
Hatchery Production
EcologicalBehavioral
Physiological
Suggests means to manipulate
Reproductive Success
Elucidate Mechanisms
GeneticsParentage
Hatchery vs. Natural
Does it work & direction
1999 2000 2001
Mean Mean SD Mean SD
Adult Steelhead
Male Length (mm)
410 52 420 62 447 50
Female Length (mm)
402 58 403 60 424 55
Fecundity 1313 522 1425 569 1711 626
Hatchery Reared Adult Steelhead
Juvenile Collection Year
Hatchery Methods and Procedures Prior to Release
CWT and AD clipped (subset PIT tagged)
Genotyped
Gill Biopsies
Steelhead Release
N = 20,000 Hatchery origin fish per yearFish released at 3 different times (blocks)
Hatchery and Natural Emigration
Collaborator: IMW Project & WDFW
Natural Origin Smolt Production
Coho salmon
Year
2000 2001 2002 2003 2004 2005 20060
4000
8000
12000
Cutthroat trout
Nu
mb
er o
f F
ish
0
4000
8000
12000
Steelhead
0
4000
8000
12000AbernathyMill Germany
Smolt Emigration
Hatchery 2003n=415
0
8
16
Hatchery 2004n=624
Fis
h C
ross
ing
An
ten
na
(%)
0
8
16
Hatchery 2005n=683
Month
0
8
16
Natural 2003n=380
Natural 2004n=533
Natural 2005n=311
11 12 01 02 03 04 05 06 07 08 09 10 11 12 01 02 03 04 05 06 07 08 09 10
Median Travel DateHatchery 2003Median date: 5/3/03
0
50
100
Hatchery 2004Median date: 4/29/04
Fis
h D
etec
ted
at
An
ten
na
(%)
0
50
100
Hatchery 2005Median date: 5/5/05
Month
0
50
100
Natural 2003Median date: 4/21/03
Natural 2004Median date: 4/30/04
Natural 2005Median date: 5/2/05
11 12 01 02 03 04 05 06 07 08 09 11 12 01 02 03 04 05 06 07 08 09
Diel Emigration
2003
0
10
20
30 HatcheryNatural
2005
00:00 04:00 08:00 12:00 16:00 20:00 00:000
10
20
30
2004
0
10
20
30
Fish
Cro
ssin
g A
nten
na (%
)
Time
• Smolt production is equivalent between pre- and post-hatchery production years
• Hatchery origin fish emigration rates, timing, and patterns are similar to natural origin fish
Production/Emigration Summary
Physiological & Morphological Sampling
1
23
4 5
8
9
101112
13
17
A. Landmarks
B. Distances-Truss Network
C. Significant discriminant coefficients
Morphological Analysis
Hatchery migrants were longer than natural migrants
Na+, K+ ATPase Activity
Release Block
1 2 3
Na
+, K
+ A
TPas
e(
mol
-P x
g-p
rot
-1 x
h-1
)
0
2
4
6
8
10Hatchery fishNatural fish
Release Block
1 2 3
Release Block
1 2 3
2003 2004 2005
Plasma Na+ & OsmolalityP
lasm
a [N
a+]
(mM
)
125
150
175
200
225
250
Hatchery fishNatural fish
Pla
sma
Osm
olal
ity
(mO
sm)
300
350
400
450
Release Block
1 2 3125
150
175
200
225
250
Release Block
1 2 3
300
350
400
450
2004
2004
20052005
•Hatchery and Natural steelhead of similar genetic parentage differ morphologically and physiologically.
•The observed characteristics provide a baseline measure.
•We will continue to monitor and determine if adult return rates and reproductive success is affected.
Summary
Adult Steelhead Returns
Natural: 36 (20 females/16 males)Hatchery: 38 (13 females/25 males)
Strays: 39 (14 females/25 males)
Relative Fitness
• Determine if the natural and hatchery fish mate randomly and produce offspring with equal survival rates in Abernathy Creek
– Parentage analysis via 11 microsatellite loci• Ground truthed the loci and method
• Estimated error rate (0.8%)
Relative Fitness
– Following our first broodyear (2005)• Genetic diversity among the broodstocks was
maintained among respective progeny
• Females on average produced 4.2 and males 3.4 offspring per spawner
• Natural fish produced 5.83 offspring per spawner
• Hatchery fish produced 1.40 offspring per spawner
• Smolt production is equivalent between pre- and post-hatchery production years
• Hatchery fish emigration rates, timing, and patterns are similar to natural fish
• Hatchery and natural steelhead of similar genetic parentage differ morphologically and physiologically
• Continuing Research– Relate physiology, morphology, and behavior to adult return rates and
reproductive success of succeeding generations– Estimate heritabilities and genetic correlations of fitness-related, life history
traits in relation to return timing, age and size at return (maturity) of succeeding generations
Conclusions