Overview

Modeling to date:– Distribution of mortality– Achieving improvements with specific actions

Building scenarios Dealing with uncertainty – some ideas

Snake River Spring/Summer Chinook Life Cycle

2 spawners 4,000-5,000 eggs

120-151 1-year-oldsto Lower Granite Dam

95-119 Migrants Below Bonneville Dam (77%

transported, 23% in River)

4-5 Youngsters To 2nd Birthday (Estuary & Ocean)

2-3 Adults return tomouth of Columbia

1-1.4 Migrants return to spawning grounds

0.50

0.60

0.70

0.80

0.90

1.00

1.10

Lower C

olum

bia

Upper C

olum

bia S

pr

Snake

River

Spr/S

um

Snake

River

Fal

l

Upper W

illam

ette

Colum

bia R

iver

Chum

Lower C

olum

bia

Mid

dle C

olum

bia

Upper C

olum

bia

Snake

River

Upper W

illam

ette

Po

pu

lati

on

Gro

wth

Rat

e

Hatchery fish reproductive success = 1

Hatchery fish reproductive success = 0

Rate of population change – Accounting for hatchery fish

Chinook Steelhead

How can we give fish what they need to survive and

recover?

Hydropower

Improvements to hydropower system

Past – passage improvements Future options

– Passage improvements» Flow and spill measures

– Dam breaching

Past vs. current passage survival

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Current High harvest,improved hydro

Low harvest,unimproved

hydro

High harvest,unimproved

hydro

An

nu

al p

op

ula

tio

n g

row

th r

ate

Snake River spr/sum chinook

Option 1 – anticipated changes with passage improvement

Snake River Fall Chinook High Needed Change

0.8

1.0

1.2

1.4

1.6

1.8

0.00 0.05 0.10 0.15 0.20

Direct and Indirect (D=.24) Hydrosystem Survival (Juvenile * Adult)

Pro

po

rtio

na

l Ch

an

ge

In O

the

r L

ife

Sta

ge

Su

rviv

al

100% Extinction Risk in 100 Yrs and 0% in 24 Yrs 5% Extinction Risk In 100 Yrs

50% Recovery in 48 Years 50% Recovery in 100 Years

Base (1980-96 Returns) Current

Hydro RPA

Harvest – maximum benefits

0.500 0.600 0.700 0.800 0.900 1.000 1.100 1.200 1.300 1.400

L. Columbia ChinookU. Columbia Spr Chinook

Snake R. Spr/Sum ChinookSnake R. Fall ChinookU. Willamette Chinook

L. Columbia Winter SteelheadMid Columbia Steelhead

U. Columbia SteelheadSnake R. Steelhead

U. Willamette Steelhead

Population Growth Rate

Maximum Population Growth Rate (Zero Harvest) Current PopulationGrowth Rate

Are there life stages at which management actions might be most

fruitfully aimed?

Sensitivity Test – Standard reductions in mortality

0

0.1

0.2

0.3

0.4

0.5

freshwater proportiontransported

downstreamsurvival

estuary/earlyocean

adult ocean upstreammigration

harvest

% c

han

ge

in l

amb

da

Snake River Spring/Summer Chinook Life Cycle

2 spawners 4,000-5,000 eggs

120-151 1-year-oldsto Lower Granite Dam

95-119 Migrants Below Bonneville Dam (77%

transported, 23% in River)

4-5 Youngsters To 2nd Birthday (Estuary & Ocean)

2-3 Adults return tomouth of Columbia

1-1.4 Migrants return to spawning grounds

Survival vs. sedimentation

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60

Percentage Fine Sediments

Em

bry

o S

urv

ival

(%

)

Steelhead

Chinook

Hatchery – Genetic concerns

Inadvertent selection due to hatchery practices reduces fitness of hatchery fish. Interbreeding of hatchery and wild fish may affect fitness of wild fish as well.– Domestication – seen in as little as a single

generation– Stock transfers

Hatchery – Ecological concerns

10 20 30 40 5010 20 30 40 50-3

-2

-1

0

1

2

Per

cent

sur

viva

l wild

chi

nook

(lo

g)

Number of hatchery spring chinook released (millions)

r2 = 0.06 r2 = 0.73

Average Ocean Productivity Poor Ocean Productivity

Building scenarios

Combinations of actions – when one isn’t enough

Interactions between actions Continuing degradation in habitat/other

environmental factors

Major areas of uncertainty

Hatchery fish masking – what is the TRUE population status?

Interactions between life stages – does survival/growth/experience in one stage affect survival/fitness in another?

Impacts of particular actions

Snake River Spring/Summer Chinook Life Cycle

2 spawners 4,000-5,000 eggs

120-151 1-year-oldsto Lower Granite Dam

95-119 Migrants Below Bonneville Dam (77%

transported, 23% in River)

4-5 Youngsters To 2nd Birthday (Estuary & Ocean)

2-3 Adults return tomouth of Columbia

1-1.4 Migrants return to spawning grounds

Some possible approaches

Different questions –– What actions (or areas) are important

REGARDLESS of the potential future?– Are there easy actions that might be useful for

bet-hedging against an unlikely future?– Which pieces of information would be most

important to have (would help us reduce our uncertainty)?