320 likes | 436 Views
Effects of Domestication on Hatchery and Wild Spring Chinook Phenotypic and Demographic Traits: What Have We Observed So Far?. Curtis M. Knudsen 1 , Steve L. Schroder 2 , Mark V. Johnston 3 , Todd N. Pearsons 2 , C. A. Busack 2 , William J. Bosch 3 , and David E. Fast 3
E N D
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 Consulting 2 Washington Department of Fish and Wildlife 3 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
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
Hatchery Control vs SH Comparisons • 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
Hypothetical Trends NO 900 SH 850 800 HC Phenotypic trait 750 700 650 600 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Return year
HC SH NO 63 61 POHP length (cm) 59 57 2006 2007 2008 2009 Return year Age 4 POHP length * * *
HC 48 SH NO 46 44 POHP length (cm) 42 40 38 2005 2006 2007 2008 2009 Return year Age 3 POHP length * * *
SH 270 NO HC 265 Median spawn date 260 255 2006 2007 2008 2009 Return year Median Spawning Date CESRF * * * *
SH Jacks HC jacks 40% NOR Jacks 30% Proportion age 3 jacks 20% 10% 0% 2002 2003 2004 2005 Brood year Proportion Jacks Produced by Broodyear
SH 0.23 NO HC 0.21 Gonadosomatic Index 0.19 0.17 2006 2007 2008 2009 Return year Gonadosomatic Index *
900 850 800 SH Gamete mass (g) 750 NO HC 700 650 600 2005 2006 2007 2008 2009 2010 Return year Total Female Gamete Mass
2007 ANCOVA: Equal slopes p=0.014 7.2 7.0 6.8 loge(Gamete mass) Origin 6.6 HC SH 6.4 6.2 6.0 3.9 4.0 4.1 4.2 4.3 loge(POHP)
7.5 7.0 Loge(Gamete Wt) 6.5 Origin HC 6.0 SH 5.5 3.7 3.8 3.9 4.0 4.1 4.2 4.3 Loge(POHP) 2008 ANCOVA: Equal slopes p=0.442
2009 Adult Male Gonadosomatic Index ANOVA HC>SH=NO p<0.01 0.15 0.10 HC Adult Male GSI SH 0.05 NO 0.00 1 2 3 4 5 Body Wt (kg)
SH NO HC Fecundity 5000 4500 Fecundity 4000 3500 3000 2006 2007 2008 2009 Return year
HC♀’shave 7% greater fecundity ANCOVA equal means p=0.054 9.0 HC SH 8.5 loge(Fecundity) 8.0 7.5 3.8 3.9 4.0 4.1 4.2 4.3 loge(POHP) Fecundity vs POHP length 2008
SH 0.21 NO HC 0.20 0.19 Mean Egg mass (g) 0.18 0.17 0.16 2006 2007 2008 2009 Return year Mean Egg Mass * *
2008 Results: SH eggs are 9% larger than HC eggs ANCOVA equality of means p=0.037 -1.3 SH HC -1.5 loge(Eggwt) -1.7 -1.9 1.0 1.5 2.0 loge(♀ Body weight)
Origin HC SH NO Fry Length at ponding BY08 ANCOVA equal slopes p<0.001 NO SH 6.1 6.0 HC 5.9 5.8 loge(Fry Body wt) 5.7 5.6 5.5 5.4 3.50 3.55 3.60 3.65 loge(Fork length)
HC SH NO Mean Survival to Eyed-egg Stage (+1 se) 95% 90% 85% Survival eyed egg stage (%) 80% ANOVA 2-way Origin x Broodyear: HC significantly higher survival than SH p=0.046 75% 70% 2007 2008 2009 Return year
Female Male b b a a b a b a b a a a a Change in Body Wt At CESRFAdjusted for Holding Time and Initial Body Weight 0.8 0.7 0.6 0.5 Delta Body Mass (kg) 0.4 0.3 HC SH NO HC SH NO HC SH NO HC SH NO 2009 returns 2008 returns
SH - 1 gen domestication HC - 2 gen domestication Mini-jack/Precocious Male Production 60% 50% * * 40% * Pre-Release Mini-Jack Percentage 30% * 20% 10% 0% BY 2002 BY 2003 BY 2004 BY 2005 BY 2006 BY 2007 Figure modified from Neeley, D. 2009. HxH vs NxN Comparison Draft Summary for Juvenile Traits.
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
Domestication • Domestication - Any genetic changes that result directly or indirectly from human efforts to control the environment experienced by a population. • Domesticationselection - “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.