COMPARATIVE SURVIVAL STUDY Chapter 3: Annual SAR by study category

and ratios of SARs

Comparisons of SARsTransport to In-RiverBy hatchery groupHatchery to WildSp/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 = SARtransport / SARinriver

• T0 = category of smolts transported from LGR, LGS or LMN, number of smolts expressed in LGR equivalents

• C0 = category of smolts migrating through the hydrosystem that were not collected at transport projects LGR, LGS or LMN, in LGR equivalents

• C1 = 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

Wild Spring/Summer Chinook

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

Migration Year

SA

R E

sti

mate

sarT0

sarC0

– 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

Wild Steelhead

0.00

0.01

0.02

0.03

0.04

0.05

1997 1998 1999 2000 2001 2002 2003Migration Year

SA

R E

sti

mate

sarT0

sarC0

• In-river SARs: Wild Chinook > Hatchery Chinook• Transport SARs: Some Hatchery SARs > Wild SARs

In-river SAR Transport 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)

Hatchery & Wild Chinook

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

ln(T

IR)

WildDWORRAPHMCCAIMNHCATH

Transport beneficial

Transport detrimental

Adult upstream migration survival (BON – LGR) is also affected by the juvenile migration experience.

50

60

70

80

90

100

LGR

LGSdownInrive

r

Su

cce

ssfu

l (%

)

50

60

70

80

90

100

LGR

LGSdownInrive

rS

ucc

ess

ful (

%)

•~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

tran

spor

t

tran

spor

t

tran

spor

t

tran

spor

t

Hatchery Chinook Wild 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: C1 < C0 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%

Wild Snake River spring/summer Chinook

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

1994 1996 1998 2000 2002 2004Migration year

SA

R

90% ULBootstrap average90% LL2% NPCC Objective6% NPCC Objective

Snake River wild Steelhead

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

1997 1998 1999 2000 2001 2002 2003

Migration year

SA

R

90% UL

Bootstrap average

90% LL

2% NPCC Objective

6% NPCC Objective

McCall hatchery Chinook

0.0%

1.0%

2.0%

3.0%

4.0%

1997 1998 1999 2000 2001 2002 2003 2004

Migration year

SA

R

90% UL

Bootstrap average

90% LL

2% minimum

Dworshak hatchery Chinook

0.0%

1.0%

2.0%

3.0%

4.0%

1997 1998 1999 2000 2001 2002 2003 2004

Migration year

SA

R

90% UL

Bootstrap average

90% LL

2% minimum

Imnaha hatchery Chinook

0.0%

1.0%

2.0%

3.0%

4.0%

1997 1998 1999 2000 2001 2002 2003 2004

Migration year

SA

R

90% UL

Bootstrap average

90% LL

2% minimum

Good precision - hatchery Chinook SARs

Poor precision – aggregate hatchery steelhead SARs

Snake River hatchery Steelhead

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

1997 1998 1999 2000 2001 2002 2003

Migration year

SA

R

90% UL

Bootstrap average

90% LL

2% minimum

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

Ricker residuals

-5

-4

-3

-2

-1

0

1

2

1950 1960 1970 1980 1990 2000

Brood year

Res

idu

als

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

Snake vs. John Day wild stream-type Chinook (PIT tags)

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

1999 2000 2001 2002 2003 2004 2005

Migration year

SA

R (

1st

dam

to

BO

N)

Snake

John Day

NPCC 2-6% SAR

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 (1st to 3rd 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

Snake River spring/summer Chinook Smolt-to-Adult Return Rates (SAR)

0%

1%

2%

3%

4%

5%

6%

7%

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Migration year

Pre

ha

rve

st

SA

R

run reconstruction adult recruits

CSS

NPCC objective 2%

NPCC objective 6%

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 - 45oN – (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)

0

5

10

15

20

25

30

35

40

45

1929 1939 1949 1959 1969 1979 1989 1999

Wat

er T

rave

l Tim

e (d

ays)

Expected change in SARsvs. 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

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0 5 10 15 20 25 30 35 40

Water Travel Time

SA

R

average PDO & Upwell

good ocean SepPDO = -1; NovUp = -116

poor ocean SepPDO = 1; NovUp = -33

Best fit (adj. R2=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)

SARs: Run reconstruction vs. CSS PIT tag

0%

1%

2%

3%

4%

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

Migration year

SAR

(LGR

-LGR

)

SAR run reconstruction

90% LL

SAR CSS PIT

90% UL

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