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Reintroduction program above Cougar Dam: Assessment of genetic diversity and searching for adfluvial Chinook Nick Sard, Dave Jacobson, Michael Hogansen, Kathleen O’Malley, Marc Johnson, Michael Banks Bob Heims, U.S. Army Corps of Engineers
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Tissue sampling Trap and haul facility operational History of Chinook reintroduction above Cougar Dam
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Adult cohorts were assigned to age-3 to -6 NOR adult returns 2007200820092010201120122013 Offspring – NOR Chinook captured at trap and haul facility 3456345
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Population is not meeting demographic replacement CRR = Number of offspring / Number of parents *Females only Sard et al. In prep.
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Most NOR Chinook retuning later in the spawning season were migrants Migrants September 1 st Sard et al. In prep.
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Genetics: Definitions and examples 5’…gatcggacatacatacatagtatta...3’ A2 Allele 1 – copy from Mom Allele 2 – copy from Dad Locus – specific location in the genome Allele – character state at a locus Genotype – alleles an individual has at a given locus Locus Alleles FishLocus 1 #1A1A2 Genotype A1
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Assessment of genetic variation Heterozygosity Proportion of individuals that have different alleles at a given locus Number of alleles FishLocus 1 #1A1A2 #2A1 #3A1A2 #4A2 Heterozygosity: 2/4 = 0.5 Alleles = 2 Our study: 8 loci Expectation: Reduction in alleles Variance in fitness, low CRR No change in heterozygosity Low power
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2007200820092010201120122013 First approach: Parent to offspring Offspring – NOR Chinook captured at trap and haul facility 3456345
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Alleles were lost Paired t-test: 95 CIs
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No change in heterozygosity *Low power to detect changePaired t-test: 95 CIs
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2007200820092010201120122013 Second approach: One return cohort Offspring – NOR Chinook captured at trap and haul facility Accounts for overlapping generations X * * Assumes no LSDR method
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Alleles were lost Paired t-test: 95 CIs
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No change in heterozygosity Paired t-test: 95 CIs*Low power to detect change
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Do NOR migrants restore or contribute new genetic variation? Migrants September 1 st
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Migrants restored lost and contributed new genetic variation Error bars: SE * *No LSDR *
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We found similar results in reintroduction program above Foster Dam Performed identical analyses Reduction in number of alleles No change in heterozygosity CRR ≈ 1 U.S. Army Corps of Engineers
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Conclusions Genetic variation is being lost Dam and river passage, ocean survival, etc. Migrants may offer a potential solution May not be productive in the long run They may impede adaptation Loss to their own source population(s) Our ongoing studies provide data Inform managers Monitor strategies to evaluate effectiveness LSDR
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Searching for adfluvial Chinook
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http://www.nwp.usace.army.mil/Locations/WillametteValley.aspx ? Is there genetic evidence for adfluvial Chinook above Cougar Dam?
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20082009201020112012 Adults were assigned to juveniles outmigrating the following year Offspring – juveniles captured in screw trap Sard et al. Submitted. CJFAS
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Juveniles are sampled above the dam Screw trap Genotyped 2,000 / year
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Some offspring are missing at least one parent
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Three hypotheses to explain missing parents: 1.Genotyping error and assignment criteria 2.Incorrect sex identification of adults 3.Unsampled adfluvial Chinook reside above the dam
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Some offspring remain unexplained after testing hypotheses 1 & 2 Mean values for each hypothesis
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Known grandparent pairs can be used to identify missing parents ? Grandparent pair Parent Grandoffspring (Juveniles) Grandparent pair – grandoffspring trio Our study: 11 loci 35 alleles/locus
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We calculated the number of observed trios expected by chance …
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Preliminary evidence suggests adfluvial Chinook may reside above Cougar Dam Searched for age-1 to -4 missing adults 15 comparisons 13 of 15: Observed trios > expected by chance Two more adult-juvenile pedigrees to assemble Increase age-1 to -4 comparisons Add new age-5 and -6 comparisons
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Adfluvial parents may account ~7% of offspring missing a parent Generalized One year - 2011 Anadromous parents Anadromous x Adfluvial? Adfluvial x Adfluvial? No > Age-4 comparisons
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Key points Part 1: Assessment of genetic variation Genetic variation is being lost Migrants boost and restore diversity Part 2: Searching for adfluvial Chinook Two more adult-juvenile pedigrees to assemble Test all putative grandparent-grandoffspring trios Genotype at 5 more loci
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Acknowledgements ODFW Mark Wade Nik Zymonas Lisa Borgerson Kanani Bowden Ben Clemens Oregon State University Carl Schreck Jen Britt Sana Banks Miles Naughton USACE Greg Taylor Doug Garletts Chad Helms David Griffith
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Some alleles lost are likely due to genetic drift HighLow
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Exp. 1 : Genotyping error does not explain all missing parents Simulated data 800 parents, 2000 offspring, 2% genotyping error rate
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Exp. 2: Background on assignments ? Lowest probability of being false? 0.001 0.01
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? Lowest probability of being false? 0.001 0.01 Exp. 2: Background on assignments
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OffspringMotherFather Kid_001Mom_001Dad_001 Kid_002UnknownDad_001 Kid_003Mom_002Unknown ……… Male Female? Female Male? Locus 1 Locus 2 101102201202 Exp. 2: Background on assignments
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OffspringMotherFather Kid_001Mom_001Dad_001 Kid_002UnknownDad_001 Kid_003Mom_002Unknown ……… Male Female? Female Male? Locus 1 Locus 2 101102201202 101103202204 Male? Exp. 2: Background on assignments
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Incorrect sex identification does not explain all missing parents
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Grandparentage analysis approach TypeGP Year Missing Parent Year 200820092010201120122013 Missing Father 2007123456Age 2008123451 200912342 20101233 2011124 201215 Missing Mother 200734566 2008345 200935 20103 2011
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Preliminary evidence suggests adfluvial Chinook reside above Cougar Dam TypeGP Year Missing Parent Year 200820092010201120122013 Missing Father 2007123456Age 2008123451 200912342 20101233 2011124 201215 Missing Mother 200734566 2008345 200935Obs. > Exp. 20103Yes 2011No
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