Effects of Domestication on Hatchery and Wild Spring Chinook Phenotypic and

Demographic Traits: What Have We Observed So Far?

Curtis M. Knudsen1, Steve L. Schroder2,

Mark V. Johnston3, Todd N. Pearsons2,

C. A. Busack2, William J. Bosch3,and David E. Fast3

1 Oncorh Consulting2 Washington Department of Fish and Wildlife3 Yakama Nation

Purpose:

• Overview of what we’ve observed in terms of domestication's effects on demographic and phenotypic traits– Size at age– Spawn timing– Jack production– Gametic traits

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The YKFP spring chinook hatchery program was designed to minimize domestication effects.

• use only wild-origin broodstock• limit the size of the program so as not to overwhelm the

naturally spawning population (mean 52%; 20-76%)• take no more than 50% of the wild returns into the hatchery• utilize factorial crosses during artificial matings• limit the proportion of jacks in the broodstock• randomly mate individuals• use “best culture practices” such as relatively low rearing

densities • volitionally release juveniles at sizes larger than, but

comparable to, wild-origin smolts

•Both share common hatchery and post-release environments

•SH returns experienced one generation of hatchery selection

•HC returns experienced two generations of hatchery selection (BY2002 to BY2005)

•Differences in their phenotypic traits should be expressions of genetic differences due to the one additional generation of hatchery selection experienced by the HC line

Hatchery Control vs SH Comparisons

Hypothetical Trends

600

650

700

750

800

850

900

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Return year

Ph

enot

ypic

tra

it

HC

SH

NO

Size-at-Age(reflecting growth rates)

Age 4 POHP length

57

59

61

63

2006 2007 2008 2009

Return year

PO

HP

len

gth

(cm

)

HCSHNO

*

**

Age 3 POHP length

38

40

42

44

46

48

2005 2006 2007 2008 2009

Return year

PO

HP

len

gth

(cm

)

HC

SH

NO

* *

*

255

260

265

270

2006 2007 2008 2009

Return year

Med

ian

sp

awn

date

SH

NO

HC

Median Spawning Date CESRF

* *

* *

Proportion Jacks Produced by Broodyear

0%

10%

20%

30%

40%

2002 2003 2004 2005

Brood year

Pro

por

tion

age

3 j

ack

s

SH Jacks

HC jacks

NOR Jacks

Gametes

0.17

0.19

0.21

0.23

2006 2007 2008 2009

Return year

Gon

ados

omat

ic I

nd

ex

SH

NO

HC

Gonadosomatic Index

*

Total Female Gamete Mass

600

650

700

750

800

850

900

2005 2006 2007 2008 2009 2010

Return year

Gam

ete

mas

s (g

)

SH

NO

HC

3.9 4.0 4.1 4.2 4.3

loge(POHP)

6.0

6.2

6.4

6.6

6.8

7.0

7.2

loge(Gamete mass)

SH

HC

Origin

2007 ANCOVA: Equal slopes p=0.014

SH

HC

Origin

2008 ANCOVA: Equal slopes p=0.442

3.7 3.8 3.9 4.0 4.1 4.2 4.3

Loge(POHP)

5.5

6.0

6.5

7.0

7.5

Log

e(G

amet

e W

t)

1 2 3 4 5Body Wt (kg)

0.00

0.05

0.10

0.15

Ad

ult

Mal

e G

SI

NOSH

HC

ANOVA HC>SH=NO p<0.01

2009 Adult Male Gonadosomatic Index

Fecundity

3000

3500

4000

4500

5000

2006 2007 2008 2009

Return year

Fec

un

dit

ySH

NO

HC

3.8 3.9 4.0 4.1 4.2 4.3

loge(POHP)

7.5

8.0

8.5

9.0

loge(Fecundity)

HC

SH

HC ♀’s have 7% greater fecundityANCOVA equal means p=0.054

Fecundity vs POHP length 2008

Mean Egg Mass

0.16

0.17

0.18

0.19

0.20

0.21

2006 2007 2008 2009

Return year

Mea

n E

gg m

ass

(g)

SHNOHC

*

*

1.0 1.5 2.0

loge(♀ Body weight)

-1.9

-1.7

-1.5

-1.3

loge(Egg wt)

HC

SH

2008 Results:SH eggs are 9% larger than HC eggsANCOVA equality of means p=0.037

3.50 3.55 3.60 3.65

loge(Fork length)

5.4

5.5

5.6

5.7

5.8

5.9

6.0

6.1

loge(Fry Body wt)

NOSHHC

Origin

Fry Length at ponding BY08

ANCOVA equal slopes p<0.001

NOSH

HC

70%

75%

80%

85%

90%

95%

2007 2008 2009

Return year

Su

rviv

al e

yed

egg

sta

ge (

%)

Mean Survival to Eyed-egg Stage (+1 se)

HC

SH

NO

ANOVA 2-way Origin x Broodyear:HC significantly higher survival than SH p=0.046

Change in Body Wt At CESRFAdjusted for Holding Time and Initial Body Weight

2008 returns 2009 returns

0.3

0.4

0.5

0.6

0.7

0.8

HC SH NO HC SH NO HC SH NO HC SH NO

Delta Body Mass (kg)

Male

Female

a

a bb

aa

b

a

a

ba

a

b

Mini-jack/Precocious Male Production

0%

10%

20%

30%

40%

50%

60%

BY 2002 BY 2003 BY 2004 BY 2005 BY 2006

Pre

-Rel

ease

Min

i-Ja

ck P

erce

ntag

e

BY 2007

Figure modified from Neeley, D. 2009. HxH vs NxN Comparison Draft Summary for Juvenile Traits.

SH - 1 gen domestication

HC - 2 gen domestication

*

**

*

Observations Phase 2

• Age 4 SH and HC fish have increased their growth rates more rapidly over time than NO fish and in 2009 were approximately equal in size to NO fish.

• Spawn timing of SH fish at CESRF was significantly earlier than NO fish, HC earlier than NO but too few data points at this time

• The more generations of domestication the less body mass lost during holding at CESRF

Observations – cont’d

• In a few return years gametic trait means were significantly affected by an additional generation of domestication

• Within certain years gametic traits exhibited significant differences such as:– The rate of gamete biomass production (kg eggs per cm

change in body length)

– The rate of egg production (# eggs per kg body growth)

– Milt production (GSI)

Observations – cont’d

• Survival to the eyed egg stage within the hatchery is greater for HC than SH fish

• The proportion of males maturing as precocious males was significantly reduced by an additional generation of domestication selecting against that life history type

• The proportion of males maturing as age 3 jacks was not different between HC and SH, but was greater than NO fish

Acknowledgements

• Yakama Nation Roza Adult Monitoring Facility Crew

• Cle Elum Supplementation Research Facility Crew

• WDFW Ecological Interactions Crew

• Bonneville Power Administration for providing funding

Questions?

Domestication• Domestication - Any genetic changes that result directly or indirectly

from human efforts to control the environment experienced by a population.

• Domestication selection - “any change in the selection regime of a cultured population relative to that experienced by the natural population”– Broodstock selection and holding– Mating practices– Incubation– Juvenile Rearing– Release

Waples, R. S. 1999. Dispelling some myths about hatcheries. Fisheries 24(2):12-21.