COMPARATIVE SURVIVAL STUDY Chapter 3: Annual SAR by study category and ratios of SARs Comparisons of SARs Transport to In-River By hatchery group Hatchery to Wild Sp/Su Chinook to Steelhead Evaluate effectiveness of smolt transportation relative to other passage routes through dams and reservoirs

Snake River spring/summer Chinook and steelhead Wild Chinook Aggregate Snake (above LGR) Hatchery Chinook DWOR RAPH MCCA IMNA CATH - AP Wild Steelhead Aggregate Snake Hatchery Steelhead Aggregate Snake

Definitions SAR = LGR adults / LGR smolts TIR = SAR transport / SAR inriver T 0 = category of smolts transported from LGR, LGS or LMN, number of smolts expressed in LGR equivalents C 0 = category of smolts migrating through the hydrosystem that were not collected at transport projects LGR, LGS or LMN, in LGR equivalents C 1 = category of smolts migrating through the hydrosystem that were collected and bypassed at one or more of transport projects

–SARs: Wild Chinook showed no benefit from transportation (on average) Exception in extreme drought year 2001 SAR = LGR adults/LGR smolts

–SARs: Wild steelhead benefited from transportation (on average) Benefit is relative In-river conditions less than optimal (e.g., before court-ordered spill) Wide CI before 2003

In-river SARs: Wild Chinook > Hatchery Chinook Transport SARs: Some Hatchery SARs > Wild SARs In-river SARTransport SAR

SAR ratios: SAR(Transport) / SAR(In-river) = TIR Hatchery Chinook - relatively more benefit from transportation than wild –TIR generally positive for hatchery populations (MCCA > RAPH > DWOR) –TIR slightly negative for wild populations (except 2001) Transport beneficial Transport detrimental

Adult upstream migration survival (BON – LGR) is also affected by the juvenile migration experience. ~10% lower adult migration success for LGR transport compared to LGS/LMN transport or in-river migration Implication for straying of transported fish into other populations transport Hatchery ChinookWild Chinook

Conclusions: Annual SAR by study category and ratios of SARs Wild Chinook – no benefit from transportation (on average) Hatchery Chinook - relatively more benefit from transportation than wild; varied among hatcheries Wild and hatchery steelhead – relative benefit from transportation; wide CI Relative transport benefit greater in extreme drought year (2001) with poor in-river conditions Transported wild and hatchery Chinook and steelhead smolts died at greater rate in estuary and ocean than in-river migrants (D < 1) Process of collection/bypass compromised SARs: C 1 < C 0 in wild and hatchery Chinook and steelhead Transportation from LGR reduced adult upstream migration success (straying/mortality)

COMPARATIVE SURVIVAL STUDY Chapter 5: Evaluation and Comparison of Overall SARs Comparisons of SARs NPCC 2% - 6% SAR goal Snake vs. John Day wild Snake vs. Carson Hatchery Multiple regression analyses Do SARs meet regional goals? Are Snake River SARs similar to downriver SARs? What management and environmental factors influence SARs?

Overall SARs of wild Chinook and steelhead fell short of the NPCC 2-6% SAR objectives: – NPCC: 2% minimum, 4% average for recovery –Wild Chinook average = 0.8% –Wild steelhead average = 1.6%

Good precision - hatchery Chinook SARs Poor precision – aggregate hatchery steelhead SARs

Upriver / Downriver SAR comparisons

Snake River life-cycle survival rates declined with FCRPS Recent survival of Snake River Chinook ~ 1/3 to ¼ that of downriver Chinook Snake R. John Day R. Schaller et al. 1999; Deriso et al. 2001; Schaller and Petrosky 2007 CSS: Do we see similar magnitude of differential mortality in SARs? Can life history differences explain the differential shift in mortality?

Snake River wild SARs ~¼ of John Day SARs –8 dams vs. 3 dams –SAR data consistent with spawner-recruit analyses

Life history characteristics: Snake vs. John Day wild No consistent, systematic differences in smolt size (FL) Emigration timing from tributaries within a similar time frame (with greater variation for Snake) Rate of emigration similar (1 st to 3 rd dam), a function of water velocity Snake smolts estuary arrival timing ~ 7-10 days later than John Day smolts (a function of FCRPS) When arrive to estuary at same time, Snake SARs are < John Day SARs A “natural experiment”; weight of evidence

Multiple Regression Analysis: Historic Snake River Chinook SARs vs. smolt migration and ocean/climatic indices

Coastal Upwelling Process Pacific Decadal Oscillation Interdecadal climate variability in the North Pacific – (Sea Surface Temperature) Coastal Upwelling Index based upon Ekman's theory of mass transport due to wind stress - 45 o N – (productivity) “Good Ocean” Cool phase PDO April Upwelling Oct Nov Downwelling

Water Travel Time: Lewiston to Bonneville Dam WTT influences smolt travel time & reach survival pre-dam ~2 days; current ~ 19 days (10-40 days) 1938 (BON), 1953 (MCN), 1957 (TDD), 1961 (IHR), 1968 (JDA), 1969 (LMN), 1970 (LGS), 1975 (LGR)

Expected change in SARs vs. WTT, PDO & Upwelling WTT significant variable in all best-fit models i.e., Snake River SARs not just due to ocean condition Analysis does not use downriver populations Response to WTT - similar to results using upriver/downriver populations Best fit (adj. R 2 =0.64), best 3 parameter model Current WTT Pre-dam WTT

Do PIT tag SARs represent SARs of the run at large? Run reconstruction (RunRec) SARs slightly larger than point estimate PIT SARs RunRec SARs fell within the 90% CIs of for 5 of 8 years Unresolved issues with wild adult accounting for RunRec SARs: assessing bias is difficult For analyses using ratios of SARs, issue is of little concern (e.g., upriver/downriver, transport/in-river)

CSS – New Analytical Tools Bootstrap CI methods for SARs, ratios of SARs (Ch. 3) Method to estimate central tendency of SARs, & ratios of SARs accounting for large inter-annual variation and variable sample sizes (Ch. 4) –Within year differences of TIR – i.e., when is it best to transport? –Potential for looking at SAR differences between groups over multiple years with small or variable sample sizes Simulation model to investigate potential bias in CJS survival estimates due to assumption violations (Ch. 7) –CJS parameter estimates are robust in the presence of within- season changes in survival or detection probabilities

Conclusions Different responses of wild Chinook and wild steelhead to transportation: –maximization of survival of both species cannot be accomplished by transportation as currently implemented. Improvements in in-river survival: –can be achieved through management actions that reduce the water travel time or increase the average percent spilled. –the effectiveness of these actions varies over the migration season. Higher SARs of Snake River wild yearling Chinook were associated with: –faster water travel times during juvenile migration through the FCRPS, –cool broad-scale ocean conditions, –and near-shore downwelling during the fall of the first year of ocean residence.

Other management uses of CSS PIT-tag groups: Idaho in-season Chinook harvest management: run size run timing upstream conversion rates Survival - release to LGR SARs from LGR smolt to LGR adult McCall, Rapid River, Dworshak Imnaha and Catherine Cr. hatcheries only LSRCP programmatic and management needs for other Chinook hatcheries LSRCP tagging initiated 2007, expanded 2008 in coordination with CSS LSRCP steelhead tagging program LSRCP tagging intiated 2008 in coordination with CSS