Yakima O. mykiss Modeling Workshop Ian Courter Casey Justice Steve Cramer

Introductions What interests you most about the topic of anadromy and residency in O. mykiss? What would it take to make this a successful meeting for you?

Project Objective Quantify the influence of life-history diversity and environment on steelhead sustainability in the Yakima Basin.

Deliverables Excel-based O.mykiss life-cycle model Peer reviewed publication Updated BA Steelhead Effects Analysis

Roles and Responsibilities “Clarifying roles up front is like writing a job description – without it, you have no idea who can do what to whom.” Steve Cramer Project Advisor Yakima Joint Board / Bureau of Reclamation Project Sponsor Ian Courter Project Lead Casey Justice Lead Analyst Advisors

Choosing the Right Approach

Advisor Comments and Contributions Comments will be addressed on an individual basis. Participants who to make substantive contributions will be given coauthorship on publications.

Proposed Modeling Approach to Evaluating Drivers of Anadromous and Resident O. mykiss Abundance in the Yakima Basin

Project Background and Purpose

ICTRT Extinction Risk Analysis

Atlas of Pacific Salmon (2005)

“…abandon the typological thinking (‘steelhead’ and ‘rainbow trout’ as biologically independent units) that has pervaded the biology and management of this species...” McPhee et al. 2007

Ecotype Abundance Drivers Carrying Capacity –Size-dependent, flow-dependent Growth –Temperature dependent Survival –Smolt to adult Fecundity –Size and life-history dependent

Habitat Characteristics Favoring Residency or Anadromy High summer rearing temperatures Low summer flows Variable growth conditions Reduced capacity for adult fish High migration survival Low summer rearing temperatures High summer flows Consistent growth conditions Year-round capacity for adult fish Low migration survival AnadromyResidency

Resident Recruits Resident Spawners Genetics Environment Mature Adults NRNR Anadromous Spawners Anadromous Recruits NANA Mature Adults Genetics Environment

Juvenile Life-history Response genotype + environment = AnadromyNon-anadromy phenotype Life-History Response

“The capability to balance life-history options fits understandings of anadromy as ‘…a suite of life history traits… expressed as points along continua for each species and population.’ (Quinn & Myers 2005) as ‘…a function of variation in costs and benefits…’ (Hendry et al. 2004)…” McPhee et al. 2007

Key Concepts Resident trout produce anadromous offspring Anadromous O. mykiss produce resident offspring Resident trout and anadromous steelhead in the upper Yakima, though phenotypically different, are genetically indistinguishable

Phenotypic state is determined by a combination of environment and genotype Phenotypic state determines juvenile life- history response (anadromy or non- anadromy) “State-dependent” or “conditional” strategies allow individuals within a population to maximize their fitness Key Concepts

To appropriately model Yakima steelhead abundance drivers, exchange between life- history forms in the population needs to be accounted for.

Quantitative O. mykiss Population Assessment Abundance (1) Stochastic Population Model Productivity Diversity Spatial Structure (2) Mechanistic Model Genetic & Env Controls Survival Fecundity Juvenile Capacity Modeling Phase -Viability analysis tool -Restoration planning tool Resident Contribution

Conceptual Modeling Approach

Carrying Capacity Juvenile Life- History Response Growth (bioenergetics)Genetics Survival and Fecundity Key Model Components

FlowTemperature Territory Size (competition) Growth (bioenergetics) Food supply Capacity AbundanceBody Size Conditions:Habitat Fish Metrics: (survival) WUA (PHabSim)

* Influenced by body size Reproductive Success Fecundity* Marine Survival* ResidentAnadromous Life-history decision* Juvenile Abundance Freshwater Survival* Reproductive Success Fecundity

Recalibrated data from Hardin and Davis (1990) How do we model effects of flow on capacity?

From Grant and Kramer (1990) Rearing capacity = WUA (m 2 ) / Territory size (m 2 )

From Rand et al. (1993) and Mangel and Sattherthwaite (2008). Modeling Growth in Freshwater Growth = anabolic gains – catabolic losses Factors influencing growth: 1)Temperature 2)Food availability 3)Fish density (competition) 4)Fish size

Data from Hydromet : Satus and Toppenish temperature data?

Age-0 Age-1 Age-2 Predicted growth in the Upper Yakima

Δ Length (Observed – Expected) = mm Age-1 Juvenile Growth How does fish growth influence life-history variability?

Δ Length (Observed – Expected) = -7.8 mm Age-1 Juvenile Growth

Survival Tradeoffs Marine (smolt to adult survival) Freshwater (juvenile to adult survival) Resident Anadromous Both? Neither? Reproductive Success (population status)

Data from Ward and Slaney (1989)

Fecundity vs Body Size

Genetics Modeling Thrower et al –Heritabilities: probability of smolting and maturing Falconer 1989 –Response to selection

Communication Platforms Project website: Webinar meetings and conference calls Personal and phone correspondence

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Sashin Creek Rearing Studies 1996 Brood Weight (g) Age-2 life-historyJun-97Oct-97Jun-98 Resident43067 Mature54371 Smolt54189 Frank Thrower, pers. comm.