Salmon and society: Lessons from the Pacific Northwest

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Salmon and societyLessons from the Pacific
Northwest

• Robin Waples
• Northwest Fisheries Science Center
• National Marine Fisheries Service
• N.O.A.A
• Seattle, WA USA

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SubtextTell us how you _at_ed it updown there
so we will feel better and, perhaps,can avoid
the same problems
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Pacific salmon stocks at risk Nehlsen et al.
1991

• Number
• of stocks
• Special Concern 54
• Moderate Extinction Risk 58
• High Extinction Risk 101
• Extinct

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Coho salmon landings
ocean troll sport fisheries
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Status review scorecard
Not Species E T C Listed Chinook 2
7 1 7 Chum - 2 - 2 Coho - 3 2
1 Cutthroat - (1) 1 4 Pink - - -
2 Sockeye 1 1 - 5 Steelhead 2 8 2
3 Totals 5 22 6 24
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Why is salmon conservation important?

• Cultural, economic, spiritual reasons
• Loss of population diversity limits evolutionary
  potential of the species
• Life history diversity
• Promotes efficient use of natural resources
• Buffers productivity
• Keystone species in terrestrial (and marine)
  ecosystems

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Upstream National Research Council 1996

• General conclusion
• The long-term survival of salmon depends
  crucially on a diverse and rich store of genetic
  variation.

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Common counterarguments
There are plenty of salmon in Alaska
Salmon are colonizing species
Salmon have plastic life-history features
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Stock transfers of Pacific salmon

• "singularly unsuccessful in producing new
  anadromous stocks

Withler 1982
Stock transfers of O. nerka
Percent successful Kokanee 90 Sockeye

Wood 1995
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Risk/recovery factors for Pacific salmon

• Habitat
• Harvest
• Hatcheries
• Hydropower
• Misc (e.g., invasive species natural variability)

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214 Pacific salmon stocks at risk Nehlsen et al.
1991

• Primary factors for decline
• Habitat loss/degradation 92
• Overharvest 49
• Hatchery interactions 49

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Habitat requirements for Pacific salmon

• Ample, high quality water
• Aerated spawning gravels
• Juvenile rearing areas
• Unimpeded migration routes

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Skagit River Basin
Historical habitat
Percent change
Habitat type
-45 -64 -15 -23 -100 -100 -7 404
Sloughs Side channel Distributary Tributarie
s Hydromodified Nonhydromodified Above
culverts Above dams Main stem Lakes
860,100 m2 431,200 m2 283,500 m2 463,600
m2 124,200 m2 43,400 m2 632.4 km 735 ha
Beechie et al. 1994
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Historical changes in habitat of Puget Sound
estuaries
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Biotic integrity Coho/Cutthroat Ratio
Horner and May 1998
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4
Biotic Integrity
2
0
60
30
20
10
40
50
Watershed urbanization (TIA)
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Mean number of years between 5-year flood events

• Pristine 5
• Urbanized 1.1

Booth 1991
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Human Population Growth in Pierce, King, and
Snohomish Counties, 1860-1990
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Some dam impacts
are obvious
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Others only appear to be obvious
Snake River spring/summer chinook salmon redds
Snake River Dam construction
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Ocean conditions (PDO) have shifted
Good
Poor
Hydropower system completed
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Other impacts are less clear
Snake River spring/summer chinook smolts
1.0
0.8
Williams et al. 2001
from Raymond 1988
0.6
Juvenile Survival in Hydrosystem
0.4

• No data
• Fish passage improvements

0.2
0.0
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
Outmigration Year
24
Columbia River Salmon harvest
60
50
1935 Fishwheels prohibited
40
1988 Last sockeye season
Salmon landings (millions of pounds)
30
1965 Last Summer season
1977 Last spring season
20
10
1950 Seines, traps, set nets prohibited
0
1870
1880
1890
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
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Replacement
MSY
Recruits
Spawners
Spawners
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Snake River Steelhead
150,000
Total
Natural
100,000
Adult Run Size
50,000
0
1960
1970
1980
1990
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Why is it important to conserve wild
salmonids--what about hatcheries?

• Long-term sustainability unproven
• Catastrophic failure
• Political and funding uncertainties
• Erosion of ecological/genetic/life history
  diversity
• Loss of fitness and productivity
• Hatcheries dont promote functioning natural
  ecosystems

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Hatchery vs. wild environments

• Similarities
• Water

Differences Food Substrate Density
Temperature Flow regime Competitors
Predators
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Oregon steelhead
2.00
Local Non-Local Expected
1.60
1.20
From Chilcote 1998
0.80
Productivity
0.40
0.00
-0.40
0
25
50
75
100
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Percent hatchery
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Average Ocean Productivity
Poor Ocean Productivity
r2 0.06
r2 0.73
Survival wild chinook (log)
10
20
30
40
50
Number of hatchery spring chinook released
(millions)
Levin et al. 2001
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Risks
Benefits
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Types of benefits to be considered
Conservation
General

• Natural pops
• Harvest
• Mitigation
• Treaty obligations
• Public education

• Natural pops

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Supplementation review
Waples et al. in press

• Was it met?
• Objective Y N ?
• Broodstock collection (representative)
• Age 11 3 8
• Run timing 10 2 10
• Integrity 17 5 -
• Hatchery survival
• Prespawning (90) 12 6 4
• Egg-smolt (70) 19 2 1
• Adult-adult (2x) 12 4 6
• Population increase (20) 8 11 3
• Natural spawning (comparable) 1 2 19
• Sustainable - 2 20

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How insulated are wilderness areas from external
impacts?
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A by-product of the life cycle

• Most biomass of salmon is acquired at sea
• Results in a transfer of marine nutrients to
  terrestrial systems

Directly consumed by cohort of 2000
Adult spawners
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Brook Trout Salvelinus fontinalis
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Achord et al. 2003
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Gustafson et al. in prep
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Lawson 1993
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Oregon coast coho
Smolt-adult survival ()
Year
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Vertical slides here
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Gustafson et al. in prep
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Listed ESUs
Domain
1) Puget Sound 3 2)
Willamette/LCR 5 3) Interior Columbia
7 4) Oregon Coast
1 5) S. Oregon/N. CA 1 6)
North-central CA 3 7) South-central
CA 2 8) Central Valley 3
Total 25
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A
B
C
X
X
X
X
X
X
X
X
X
X
Which ESUs are viable?
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Risk
Diversity
High Medium Low
Total 3 5 11 North 2 3
7 South 1 2 4 Summer 2 2
0 Winter 1 3 11 Wild 3
3 2 Hatchery 0 2 9

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Conclusions

• Causes of salmon declines can be complex
• FW habitat most pervasive threat
• Habitat problems are caused by people
• Habitat that appears pristine may not be
• Salmon populations generally are not replaceable
  on ecological time scales
• Long-term effects of hatcheries on natural
  populations are uncertain but may be profound
• In PNW much has been lost, but much remains.
  Region is at a pivotal point
• Fluctuating ocean cycles declining FW
  productivity trouble for salmon