Climate insurance for NW steelhead fisheries: thoughts on incorporating the influence of variable oc

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Climate insurance for NW steelhead fisheries
thoughts on incorporating the influence of
variable ocean conditions in steelhead management

• Nate Mantua
• Climate Impacts Group
• University of Washington

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Environmental variability is large
Sept 1997 El Niño
Sept 1998 La Niña
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OPI (hatchery) coho marine survival
Why? Leading hypothesis changes in ocean
conditions impact the entire marine food-web
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upwelling food webs in our coastal ocean the
California Current
Cool water, weak stratification high nutrients, a
productive subarctic food-chain with abundant
forage fish and few warm water predators
Warm stratified ocean, few nutrients, low
productivity subtropical food web, a lack of
forage fish and abundant predators
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Upwelling impacts August 2000
temperature
Chlorophyll
Columbia River mouth
For the NW coastal ocean, spring/summer upwelling
is a key and highly variable process that
structures the coastal ocean food web
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coastal ocean impacts on coho marine survival
(Logerwell et al. 2003, Fish. Oceanogr.)

• key factors?
• Stratification
• spring transition date
• spring winds, upwelling and transport

• key factors?
• Stratification
• winter winds, downwelling and transport

?
?
1st spring at sea
1st winter at sea
A few to 100 adults in 2nd summer
10s to 100s post-smolts early summer
1000 smolts
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4 index Ocean Conditions Model hindcasts for
OPI coho marine survival, 1969-1998
Logerwell et al. 2003, Fish. Oc.
R2 .75
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Observed coherence scales in stock specific
salmon productivity
n37

• Stock by stock R/S residuals have 50
  decorrelation scales 500 to 1000km
• Similar scales of coherence come from stock by
  stock marine survival estimates based on CWTs
• (figure taken from Mueter et al., 2002, Fish.
  Oceanogr.)

n43
n40
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Scales of coherence in the coastal ocean
2500 km

• Coastal SST and upwelling wind decorrelation
  scales are largest in winter, smallest in summer
• Decorrelation scales for salmon productivity are
  similar to those for summertime SST and upwelling
  winds
• (Mueter et al., 2002, Fish. Oceanogr.)

1000 km
500 km
J F M A M J J A S O N D
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Commercial Sockeye Salmon Catches Since
1883 Bristol Bay, Alaska
Commercial catch (millions)
Composition
Hilborn et al. 2003, PNAS
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Recruits-per-spawner for Bristol Bay sockeye (by
major river system)
Year
Hilborn et al. 2003, PNAS
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Life in uncertain environments

• Risk spreading characteristics, at the
  metapopulation level, one evolutionary response
• diversity of time-space habitat use provides a
  buffer for stocks, metapopulations, and species
• a variety of sensitivities for different streams
  (e.g. Hymer WDFW, Hilborn et al. )
• different ocean sensitivities (e.g. Waples, NMFS,
  Hilborn et al.) for different stocks

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So what?(what Ive learned)

• Sustaining fish and sustaining a fishery are
  not the same things
• expectations and actions for these two goals are
  often at odds with each other
• right now, fishery managers generally failing to
  deal with climate
• true for year-to-year and decade-to-decade
  variations

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What are we managing, and why? (McEvoy 1996)

• What is a fishery?
• (1) an ecosystem (2) a group of people working,
  and (3) a system of social control

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Sustainability?

• Saving the fish
• eliminate harvests
• Restore diversity, abundance, and distribution
• restore and protect habitat
• remove barriers to fish passage (breach dams)
• accept variability
• acknowledge a lack of predictability

• Saving the fishery
• Maximize harvests
• focus on productivity, biomass/numbers
• tweak the status quo
• fish passage, hatcheries
• eliminate variability
• use hatcheries, divorce fish production from
  habitat
• emphasize prediction

ECOLOGY
POLITICS-ECONOMICS-ECOLOGY
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Where predictability matters(Holling 1993
Ecological Applications)

• 1st stream science
• system is predictable, science of parts
• ex the population, maximum sustained yield
• Experimental, seeks explanation and prediction
• implies we need certainty before taking action
• Command and Control Management
• Problem is perceived, a solution for its control
  is developed (e.g. low salmon production, build a
  hatchery)
• Reduce variability to make the system more
  predictable

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Where Predictability doesnt matter

• 2nd stream science
• Unpredictable, science of integration
• ex the ecosystem
• Comparative, seeks understanding, accepts
  inherent unknowability and unpredictability
• The Golden Rule
• Resource management should strive to retain
  critical types and ranges of variations in
  ecosystems (Holling and Meffe 1996)

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The problem?

• We cant solve 2nd stream problems with 1st
  stream approaches

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Summary and Conclusions

• A large and growing body of evidence for climate
  impacts on salmonids
• climate information may aid in improving
  management
• short term help through monitoringbiophys models
• At time frames gt 1 year into the future,
  predictability is severely limited
• environmental prediction issues now a source of
  conflict between managing fish and fisheries
• scientists must own up to the fact that we cannot
  predict the future

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What to do?

• Acknowledge and embrace uncertainty
• wild salmonids have evolved characteristics that
  cope with environmental uncertainty
• choose Monitoring over Prediction
• restore natural climate insurance for salmon
• Diversity, abundance, and distribution
• restoring lost diversity of life history
  behaviors this diversity is directly linked to
  availability of healthy, complex freshwater
  habitat
• Save the Fishery

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Saving the Fishery

• Save the Fish
• Rethink/revise goals of fishery management
• Industrial fishery model (MSY) fails to account
  for environmental uncertainty and highly limited
  predictability of populations and their food
  webs, and it fails to value the role of
  variability in the ecology of populations

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Managing for sustainability
Fish economy/interests
Legal system
nature
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• Note that this talk borrows
• heavily from
• Mantua, NJ, and RC Francis (in press) Natural
  climate insurance for Pacific northwest salmon
  and salmon fisheries finding our way through the
  entangled bank. To appear in E.E. Knudsen and D.
  MacDonald (editors). Fish in our Future?
  Perspectives on Fisheries Sustainability. A
  special publication of the American Fisheries
  Society.

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A climate scientist in the field
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Coastal Oregon regional indices and large-scale
Oct-Mar Aleutian Low variability
AL Index
AL Index
AL Index
AL Index
Spring Uwp
DJF SST0
Spring Trans
DJF SST1
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Ocean Conditions Model predictions
Predictions RY 2000 4-6 RY 2001 3-5 RY 2002
4-8 RY 2003
Washington-Oregon-California coho landings
10
6
Catch in millions of coho
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OPI survival rate ()
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4
4
2
2
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WDFW coho marine survival recordscourtesy Dave
Seiler WDFW
5 wild stocks
7 hatchery stocks