Where are all of the missing parents? Grandparentage analysis identifies reproductively successful residualized hatchery fish Mark Christie, Melanie Marine Michael Blouin

Additional gene flow from hatchery to wild Unknown trout population 60% missing parents Introduction J. McMillan

Complete sample of anadromous fish Hood River, winter run Study system

S = Steelhead N = Non-anadromous R = Residual hatchery N 1,3 S 5,6 1,61,6 S S R 1,2 S 3,4 1,3 S ? Wild Steelhead

? S 5,6 1,61,6 S Parentage

Parentage procedure 1.Correctly identify 1 true parent 2.Ensure 2nd parent is truly missing Incorporated error rates Double check that missing parent was not incorrectly sexed

Missing parents

BroodyearN Total N No Father N No Mother Missing parents H o : N No Father = N No Mother p < 0.001

S = Steelhead N = Non-anadromous R = Residual hatchery N 1,3 S 5,6 1,61,6 S S R 1,2 S 3,4 ? Broodstock

Grandparentage results

Offspring with missing fathers (N=753): 5.2 to Percent assigned to hatchery broodstock Offspring with missing mothers (N=150): 12.0 to Total (N=903): 6.3 to Expected number false matches = 0.003

Reproductive Success HatcheryWild Hatchery Trout (Wild) Anadromous Resident G-test of independence : (14) (454)(257) (25) p < 0.03

Reproductive Success HatcheryWild Hatchery 612 Trout (Wild) 5791 Anadromous Resident G-test of independence : p = 0.667

% 77% 20% Age at spawning Year broodstock grandparents spawned = Year hatchery residualized fish born Broodyear of grandoffspring = Year hatchery residualized fish spawned

Age at spawning Mann-Whitney : P < 0.001

Conclusions Grandparentage is an effective tool Residualized hatchery fish do reproduce Trout populations are very important Hatchery residualized males and females 28 % Wild Steelhead have 1 trout and 1 anadromous parent

Acknowledgements Hitoshi Araki, William Ardren, Kaitlin Bonner, Becky Cooper, Lyle Curtis, Rod French, John McMillan, Ivan Phillipsen, Catherine Searle, Jeff Stephenson, Oregon State Center for Genome Research and Biotechnology, ODFW staff, and Bonneville Power Administration.

BroodyearN Putative Lower% AssignedFpairsPr(G)Upper% Assigned Total BroodyearN Putative Lower% AssignedFpairsPr(G)Upper% Assigned E E E E E E Total E Both Sexes Total Grandparentage results

BroodyearN Total N Mother FpairsPr(φ)N No Father BroodyearN total N Father FpairsPr(φ)N No Mother Missing parents H o : N = N p < 0.001

Identification of hatchery residualized fish Hood River, winter run Study system

Grandparentage methods 1 Parent, + Broodstock Matrix No Parents, + Broodstock Matrix No Parents or Broodstock Matrix

BroodyearN Total N Mother FpairsPr(φ)N No Father BroodyearN Total N Father FpairsPr(φ)N No Mother

Grandparentage methods Broodyear of SteelheadExpected #Actual # w/ missing fathersfalse trios All years7.357 Broodyear of SteelheadExpected #Actual # w/ missing mothersfalse trios All years0.861