John Day River Major tributary to mid-Columbia River No large dams (but downstream in Columbia)

1. A life history framework to understand production of juvenile steelhead in freshwater applied to the John Day River, Oregon Jason Dunham, USGS Forest and Rangeland Ecosystem Science Center John McMillan, Department of Fisheries and Wildlife, OSU - MS Justin Mills, Department of Fisheries and Wildlife, OSU - MS Matt Sloat, Department of Fisheries and Wildlife, OSU – Ph.D. (new) Gordie Reeves, US Forest Service Pacific Northwest Research Station Chris Jordan, National Marine Fisheries Service, Northwest Fisheries Science Center

2. John Day River • Major tributary to mid-Columbia River • No large dams (but downstream in Columbia) • No hatcheries (but hatchery “strays” present) • Mix of listed “steelhead” and non-listed “rainbow trout” present • Broad-scale environmental variability

3. Major reasons for listing steelhead as a threatened species in the Mid-Columbia • Declines in abundance of wild populations • Present abundance <<< historical • Hatchery influences + uncertainty • Habitat alteration • Lack of information regarding interactions between resident rainbow trout and anadromous steelhead • Busby et al. 1996; NMFS 1999

4. Three Questions • Why “steelhead” and “rainbow” trout? • How do we tell them apart? • What do we do about it?

5. Why “steelhead” and “rainbow” trout? • Variation in migration behavior • Growth and survival tradeoffs • How to make it to maturity? Jonsson and Jonsson 1993; Hendry et al. 2004

6. Why “steelhead” and “rainbow” trout? • Variation in migration behavior • Growth and survival tradeoffs • How to make it to maturity? • Influence of sex • Once mature how to maximize fitness? • Different sexes = different problems • Males – mate with females • Females – fecundity Jonsson and Jonsson 1993; Hendry et al. 2004

7. Sex and mating tactics (e.g., Gross 1991) Mating tactic Habitat use Habitat use

8. Common mating patterns Mating tactic Habitat use Habitat use

9. Why do we care about “rainbows?” Long-term viability and life history diversity • Interbreeding of “steelhead” and “rainbows” • Increased Ne of O. mykiss

10. Why do we care about “rainbows?” Long-term viability and life history diversity • Interbreeding of “steelhead” and “rainbows” • Increased Ne of O. mykiss • Flexible expression of life history possible • Spreading risk across habitats • Buffer periods of low survival in FW or marine

11. How do we tell them apart? 1. Use of neutral genetic markers • Genetic differences among different life histories within the same basin are generally less than differences among basins (McPhee et al. 2007).

12. How do we tell them apart? 1. Use of neutral genetic markers • Genetic differences among different life histories within the same basin are generally less than differences among basins (McPhee et al. 2007). • Difficult to isolate “life history” from other confounded factors that lead to genetic isolation • Isolation by distance or habitat type • Isolation by timing of reproduction • Episodic gene flow

13. How do we tell them apart? 1. Use of neutral genetic markers • Genetic differences among different life histories within the same basin are generally less than differences among basins (McPhee et al. 2007). • Difficult to isolate “life history” from other confounded factors that lead to genetic isolation • Isolation by distance or habitat type • Isolation by timing of reproduction • Episodic gene flow • Difficult to ID what a “rainbow trout” or “steelhead” is in your sample (esp. males)

14. How do we tell them apart? 2. Direct observation • Mating behavior in the field • Spatial and temporal isolation • Zimmerman and Reeves, McMillan 2007

15. How do we tell them apart? 2. Direct observation • Mating behavior in the field • Spatial and temporal isolation • Zimmerman and Reeves, McMillan 2007 • Otolith microchemistry • Sr/Ca ratios (higher in seawater) • Zimmerman et al.

16. How do we tell them apart? 2. Direct observation • Mating behavior in the field • Spatial and temporal isolation • Zimmerman and Reeves, McMillan 2007 • Otolith microchemistry • Sr/Ca ratios (higher in seawater) • Zimmerman et al. • Examination of maturity • Mature female in freshwater ≠ steelhead • Mature male in freshwater…?

17. Two studies in the John Day River • Spatial distribution of anadromous females (Justin Mills, MS) • Indirectly inferred from juveniles (0+, 1+) • Chemistry of otolith primordium • Spatial distribution of mature individuals (John McMillan, MS) • Males • Females

18. Two studies in the John Day River • Spatial distribution of anadromous females (Justin Mills, MS) • Samples @ ODFW EMAP sites • Spatial patterns • Landscape influences • Water temperature • Water chemistry • Network position • Channel morphology • Flow regime/discharge • Barriers

19. Two studies in the John Day River • Spatial distribution of mature individuals (John McMillan, MS) • Maturation of age 1+ males • Individual condition • Body size • Prior year growth • Lipid % • Individual condition • Water temperature • Population density of O. mykiss • Alkalinity/conductivity

20. What do we do about it? • Life history expression • A “filter” for production of anadromous O. mykiss • Filter can be applied in two ways: • Manage by location (=static processes) • Manage processes that influence life history expression (=dynamic processes)

21. Natural Processes Human Influences Natural Processes Human Influences Bio-physical Environment Bio-physical Environment Abundance Productivity Abundance Productivity Processes influencing life histories Freshwater resident production Locations with different proportions of anadromy Steelhead juvenile production Steelhead juvenile production

22. Assumptions • Location: Panad = Constant (static processes) • Genetic (e.g., high heritability of anadromy) • Related to “immutable” environmental influences • Management constrained to locations with potential

23. Assumptions • Location: Panad = Constant (static processes) • Genetic (e.g., high heritability of anadromy) • Related to “immutable” environmental influences • Management constrained to locations with potential • Process: Panad = Variable processes • Flexible expression – phenotypic plasticity • Variability in males > females • Related to variable environmental influences • Some of above can be influenced by management

24. Examples • Location • Intrinsic potential (Burnett et al. 2007) • Influence of groundwater (Zimmerman and Reeves)

25. Examples • Location • Intrinsic potential (Burnett et al. 2007) • Influence of groundwater (Zimmerman and Reeves) • Process • Barriers: anadromous  resident • Emergence of anadromy from residents • Short term changes in life history related to changes in temperature (Dunham et al. unpubl)

26. 106 53 57 19 8 8 UB BR BD UB BR BD Age 1+ Age 2+ Immature Mature male Mature female 30 36 72 100% 80% 60% Occurrence 40% 20% 0% Cool Warm UB BR BD Age 0+

27. Modeling approach • Deal explicitly with life history expression in O. mykiss • Be spatially explicit • Provide multi-scale context (site versus stream network) • Integrate physical and biological processes

28. Modeling approach • Deal explicitly with life history expression in O. mykiss • Be spatially explicit • Provide multi-scale context (site versus stream network) • Integrate physical and biological processes • Inform on-the-ground decisions • Relate to specific management actions • Be easily manipulated to evaluate alternative scenarios

29. Modeling approach • Inform on-the-ground decisions • Relate to specific management actions • Be easily manipulated to evaluate alternative scenarios • Be flexible in using different sources of information • Deal explicitly with uncertainty • Easy to understand with transparent assumptions

30. Expected outcomes • A better understanding of complex relationships influencing production of juvenile steelhead in freshwater. • Identify major uncertainties. • Testable hypotheses about management alternatives  monitoring and evaluation. • A straightforward management framework and tool that can be applied to inland steelhead in general.

31. Timelines • Model of anadromy – 2008/09 • Freshwater maturation - 2008/09 • Model of freshwater productivity – 2011 • Ph.D. dissertation - 2012

32. Questions - Discussion North Fork John Day River 2006: John McMillan photo

34. Migration behavior: habitat use, dispersal, “straying” DISPERSAL RESIDENT FISH RESIDENT FISH MIGRATION HOMING HOMING “STRAY” “STRAY”