Todd Seamons and Tom Quinn University of Washington School of Aquatic and Fishery Sciences

1. Individual lifetime reproductive success of repeat spawners vs. one-time spawners Todd Seamons and Tom Quinn University of Washington School of Aquatic and Fishery Sciences

2. Hypotheses • Repeat spawners will have more offspring than one-time spawners • In terms of lifetime reproductive success

3. Hypotheses • Repeat spawners will have more offspring than one-time spawners • In terms of lifetime reproductive success • But repeat spawning fish don’t just age between brood years, they also grow

4. Reproductive success Males Dominance Female choice Longevity Body Size Hypothesized size advantages for repeat spawners

5. Reproductive success Females Fecundity Egg Size Redd Quality Body Size Hypothesized size advantages for repeat spawners

6. Other advantages? • Prior knowledge/experience? • Females • Best redd sites • Males • Spawning territories?

7. Hypotheses • Repeat spawners will have more offspring than one-time spawners • Repeat spawners will produce more than twice the average number of offspring of one-time spawners

8. Hypotheses • Repeat spawners will have more offspring than one-time spawners • Repeat spawners will produce more than twice the average number of offspring of one-time spawners • Repeat spawners will produce more offspring the second time they spawn than the first time

9. ~5 km Study site: Snow Creek Strait of Juan De Fuca Photo: Thom Johnson Port Townsend Discovery Bay Oncorhynchus mykiss Barrier waterfall Snow Creek

10. ~5 km Strait of Juan De Fuca Port Townsend Discovery Bay Permanent weir - WDFW Snow Creek

11. ~5 km Strait of Juan De Fuca Port Townsend Discovery Bay No hatchery* Snow Creek

12. ~5 km Strait of Juan De Fuca Port Townsend Discovery Bay Snow Creek

13. ~5 km Strait of Juan De Fuca Port Townsend Discovery Bay No fishing! Snow Creek

14. Sampling Adults trapped and sampled at the weir • Date • Sex • Fin clip (DNA) • Fork Length (mm) • Scales (DNA, age – Jon Sneva, WDFW)

15. Total number of adults returning to Snow Creek in 19 brood years N (M+F) Brood Year

16. Directly enumerate number of adult offspring returning to spawn Adult offspring sample year Parental brood year 1987 1989 1986 1988 2004 1982 1983 1984 19 parental brood years N (parents + adult offspring) = 1094 2000

17. Directly enumerate number of adult offspring returning to spawn Adult offspring sample year Parental brood year 1987 1989 1986 1988 2004 1982 • Scales • Fin Clip 1983 1984 19 parental brood years N (parents + adult offspring) = 1094 2000

18. Directly enumerate number of adult offspring returning to spawn Adult offspring sample year Parental brood year 1987 1989 1986 1988 2004 1982 1983 1984 Genetically match parents to returning adult offspring 2000

19. How were repeat spawners identified? • Healed opercle scar

20. How were repeat spawners identified? • Healed opercle scar • Scales • Spawn check Spawn check Photo: Michael Dauer

21. How were repeat spawners identified? • Healed opercle scar • Scales • Spawn check Spawn check Photo: Michael Dauer

22. How were repeat spawners identified? Female - 1988 • Healed opercle scar • Scales • Spawn check • DNA Female - 1989

23. More females survive to kelt than males 64% overall survival to kelt (11 years of data) 74% Range: 56-91% 54% Range: 31-84% Average proportion

24. Snow Creek repeat spawner growth • Growth • Female average = 42 mm (n = 16) • Male average = 71 mm (n = 3) • Fecundity • +350 – 450 eggs • A little over 10% increase in fecundity

25. Hypotheses • Repeat spawners will have more adult offspring than one-time spawners • Repeat spawners will produce more than twice the average number of adult offspring of one-time spawners

26. Repeat spawning females have only twice the number of adult offspring as single-time spawners 1.8 offspring / female t-test, p=0.001 ± 1 SE 0.9 offspring / female Average # offspring N=380 N=54 Spawner type

27. Repeat spawning males have a little more than twice the number of adult offspring as single-time spawners 1.2 offspring / male ± 1 SE t-test, p=0.05 0.5 offspring / male Average # offspring N=383 N=19 Spawner type

28. Hypotheses • Repeat spawners will have more adult offspring than one-time spawners • Repeat spawners will produce more than twice the average number of adult offspring of one-time spawners • Repeat spawners will produce more adult offspring the second time they spawn than the first time

29. Repeat spawning females produced slightly more adult offspring their second spawning 0.9 offspring / female 0.8 offspring / female ± 1 SE Average # offspring N=54 N=54 Spawning Year Not significantly different

30. Repeat spawning males produced all of their adult offspring their second spawning 1.2 offspring / male ± 1 SE Average # offspring 0 offspring / male N=19 N=19 Spawning Year

31. Summary - males • Repeat spawning male LRS = x2.4 one-time spawners • First time spawning males produce no adult offspring • Life-history trade off for males? • sacrifice present reproduction for future

32. Summary - females • Repeat spawning female LRS = x2 one-time spawners • In any one year, a repeat spawning female is only as good as a one-time spawning female • No obvious trade-off for females

33. Repeat spawners @ 2nd time spawning All adults Not all repeat spawners are big Proportion Length (mm)

34. Bigger is better for males (but not much) P < 0.01 r2 = 0.01 Relative reproductive success smaller bigger Relative length

35. Bigger is better for females (but not much) P < 0.01 r2 = 0.01 Relative reproductive success smaller bigger Relative length

36. Consistent repeat spawning rates • across Washington rivers Source: Busby et al. 1996

37. Snow Creek rates are about the same • but much smaller population Source: Busby et al. 1996

38. Is it important to keep repeat spawners in the population? • Would removal = fewer in the future? Probably NOT • Genetic component of repeat spawning ≈ 0 • Repeat spawning = almost all environmental • Spawning conditions • Flow at outmigration • Migration distance • Ocean conditions upon arrival • Ocean conditions for the next year

39. Is it important to keep repeat spawners in the population? • Repeat spawning = Overlapping generations • Slow the rate of loss of genetic diversity • Important for population recovery • Increased rate of recovery for small populations

40. Many many many many thanks… • Thom Johnson WDFW • Randy Cooper WDFW • Cheri Scalf WDFW • Jon Sneva WDFW • Many volunteers

41. In the field Jen McLean Caryn Abrey Ray Timm Josh Latterell Greg Mackey Ian Stewart Erin McClelland Chris Boatright Et al. Funding National Science Foundation H. Mason Keeler Endowment Many Thanks… • MMBL • Sofia • Jen McLean • Mike Canino • Tatiana Rynearson • Patrick O’Reilly • Rolf Ream • Pam Jensen • Brent Vadopalas • Ingrid Spies • Sara Feser • Jennifer Cabbarus • Anny Soon • Ann Riddle • Willy Eldridge • Erin McClelland • Et al. • Data Analysis • Kevin Brinck • Stephanie Carlson • The Quinn Group • Jen McLean • Caryn Abrey • Bobette Dickerson • Stephanie Carlson • Richie Rich • Et al.

42. 3:1 2.5:1 2:1 1.5:1 1:1 1:1.5 1:2 1:2.5 Total number and sex ratio of adults returning to Snow Creek in 19 brood years Sex ratio +F+M N (M+F) Brood Year

43. Uneven distribution of adult offspring among parents average =0.91 σ2 / μ2 = 2.67 average =0.52 σ2 / μ2 = 4.59 Proportion # adult offspring per parent 19 brood years

44. Smolts Adults Ocean Mature male parr Freshwater Juveniles Embryos

45. 0.70 0.70 0.60 0.60 0.50 0.50 0.40 0.40 0.30 0.30 0.20 0.20 0.10 0.10 0 0 3 brood years More mothers assigned than fathers ~30% Proportion Mothers Fathers ~30% Proportion mature male parr Mothers Fathers 19 brood years