Life-cycle models for the diverse and plastic Oncorhynchus mykiss: challenges and opportunities Neala Kendall*§, Rich Zabel§, and Tom Cooney§ *Washington Department of Fish and Wildlife §NOAA Fisheries, Northwest Fisheries Science Oncorhynchus mykiss life history tactics and population dynamics • Life history strategies influenced by environmental and anthropogenic factors • Life-cycle models used to better understand strategies, evaluate population dynamics spatially and temporally Jonny Armstrong John McMillan Purpose of a life-cycle model • Questions to answer using the model: – Is anadromy expected to persist into the future? – Under what environmental conditions will O. mykiss be resident or anadromous? – What life history stages represent population “bottlenecks?” – What patterns of anadromy and residency will we see given different freshwater habitat mitigation actions? O. mykiss life cycle models Freshwater Ocean Migration Decision to smolt to ocean as Mortality steelhead Immature trout Growth fish Growth Mature Maturing fish fish Maturing fish Mature Maturation fish Immature fish Maturation Mature fish Immature Spawning Mature Fishing fish Mature fish migration fish and Decision to natural return & spawn Spawning mortality Natural Natural mortality mortality Ocean Natural mortality migration Modified from Theriault et al. 2008 Existing models to help 1. Yakima River, WA anadromous/resident O. mykiss abundance and reproductive success life- cycle models (I. Courter & C. Frederiksen et al.) 2. Anadromy/residency and smolt age decision for O. mykiss (originally developed for CA populations; Satterthwaite et al. 2009, 2010) 3. Chinook and O. mykiss life-cycle matrix models for Interior Columbia River basin (but only anadromous component; ICTRT and Zabel 2007) Yakima River O. mykiss Fry Environmental Conditions life-cycle models Food Supply Temperature Flow Growth (bioenergetics) • Use freshwater food Body Size Territory Size Abundance Habitat Area (competition) (PHABSIM & 2D modeling) supply, flow, and Capacity temperature to predict Survival fish growth, survival, Cross-Ecotype capacity, and reproductive Exchange success by life history Marine Survival Freshwater Survival tactic Fecundity Anadromous Reproductive Resident Spawners Success Spawners Courter et al. 2009 Model predictions Anadromous Resident Courter et al. 2009 Anadromy/residency life-cycle model for O. mykiss • Based on fish emergence date, freshwater growth, survival, fecundity, and overall fitness • Predict maturation/residency and smolt age decision Satterthwaite Maturation decision smolting et al. 2009, 2010 decision Model predictions Maturity of age-0 females mature • Predict maturation/ residency and smolt age decision wait, smolt at age 0 mature Growth rate (mm/day) Growthrate wait, smolt at age 1 Satterthwaite et al. 2009, 2010 Emergence date O. mykiss matrix models for Interior Columbia River basin • Steelhead-only life-cycle model • Beverton-Holt functions to include density-dependent survival in freshwater • Components (adjusted in different “scenarios”): – Downstream survival (based on hydropower corridor passage) – Estuary and early marine survival (based on climate conditions) – Later marine survival – Harvest, upstream survival – Overwinter survival in fw ICTRT and Zabel 2007, Zabel et al. 2013 Interior Columbia River basin populations • Rapid River (Little Salmon River) • Potlatch River • Catherine Creek • Umatilla River • Toppenish Creek • Naches River • Satus Creek • Upper Yakima River Photo: John McMillan Example model run—Umatilla River 6000 5000 4000 3000 2000 spawners.raw[, , 3] , spawners.raw[, 1000 Population abundance Population 0 50 fish 20 40 60 80 100 Years into the future Model predictions (under baseline scenarios) • Abundance decreased over time for Yakima River basin and Umatilla River populations • Abundance increased over time for Potlatch River, Catherine Creek, & Rapid River populations Model predictions (under varying scenarios) • Changes in habitat, upriver survival, and estuary/early ocean conditions resulted in largest spawner abundance changes • Changes in habitat resulted in greatest changes in quasi-extinction probability • Changes in harvest rates resulted in smaller abundance and extinction probability changes Population-specific model predictions under various scenarios—Umatilla River Estuary and early Survival through the marine survival hydropower corridor after 100 100 years after Population abundance abundance Population Survival through the Habitat (overwinter/ hydropower corridor prespawning survival) Population-specific model predictions under various scenarios—Umatilla River Estuary and early Estuary and early marine survival marine survival after 100 100 years after Population abundance abundance Population Later marine survival Harvest rate Future work • Combine ICTRT and Zabel matrix model with Courter & Frederiksen et al. freshwater habitat conditions determinants and Satterthwaite et al. model of anadromy/residency decision Photos: John McMillan Habitat considerations need to be incorporated • First establish fish-specific side of the life-cycle model • Then incorporate freshwater habitat considerations into model • Understand how habitat changes (climate change and human modifications including restoration) may affect abundance and viability Incorporating habitat restoration into the models • Develop landscape-to-habitat functional relationships • Develop habitat-to-fish relationships • Model habitat quality (e.g., flow and temperature) and quantity using land- use and geomorphic characteristics to estimate fish capacity and survival Bartz et al. 2006, Scheuerell et al. 2006, Beechie et al. 2006 Acknowledgements • National Research Council Postdoctoral Fellowship Program • Interior Columbia TRT life-cycle modeling group • Ian Courter (Mt. Hood Consulting), Chris Frederiksen (Yakama Nation), Ethan Crawford (WDFW), ODFW La Grande office, Brett Bowersox (IDFG), and others who supplied data • NOAA Northwest Fisheries Science Center • WDFW, especially Erik Neatherlin, Jeremy Cram, Andrew Murdoch, and Thomas Buehrens Photo: John McMillan Questions? Oncorhynchus mykiss: one (two?) cool fish Photo: John McMillan Oncorhynchus mykiss: one (two?) cool fish • Very diverse life history including migration tactics (“partial migration”) • Valuable recreational and commercial fisheries • Many natural populations have declined in abundance and life history diversity over the past century, are ESA listed Photos: Jonny Armstrong Population-specific model predictions under various scenarios—Umatilla River Estuary and early Later marine marine survival survival Population abundance Population Habitat (overwinter/prespawning survival) .