A Climate Angle on Uncertainty in Salmon Recovery Scenarios

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A Climate Angle on Uncertainty in Salmon Recovery
Scenarios

• Nate Mantua Ph D
• Joint Institute for the Study of the Atmosphere
  and Oceans
• University of Washington

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Key Points

• Spatial variability
• Complex topography in PS region yields complex
  spatial patterns of hydro-climate
• Temporal variability
• Climate and weather variations cause habitat
  variations at time scales from days to decades
• Salmon in the future?
• Dont buy into long-term climate predictions!
• Careful considerations of climate uncertainty
  will help paint more realistic pictures of the
  true uncertainty in recovery scenarios

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The predictable part seasonal rhythms
Puget Sound Precip
Insolation
Oct Feb Jun
Upwelling winds at 48N
Oct Feb Jun
Jan May Sep
Amphitrite Pt SST
Oct Feb Jun
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The predictable part seasonal rhythms
Puget Sound Precip
Skagit
Oct Feb Jun
Oct Feb Jun
Puyallup
Oct Feb Jun
Skokomish
Oct Feb Jun
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Why is climate important?

• salmon have successfully colonized and occupied
  each stream type (snow-melt, runoff, and
  everything in-between)
• Different stocks employ distinct life history
  behaviors tuned to the predictable seasonal
  rhythms
• stability and variability of seasonal climate
  and environmental changes have obviously played a
  role in shaping salmon behavior at the stock level

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Variations on the seasonal rhythms
Monthly Puget Sound Precip
Skagit
70 75 80 85 90 95
00
70 75 80 85 90 95 00
Puyallup
Daily Upwelling winds
70 75 80 85 90 95
00
70 75 80 85 90 95 00
Skokomish
Monthly Amphitrite Pt SST
70 75 80 85 90 95 00
70 75 80 85 90 95
00
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Upwelling impacts (August 2000)
Chlorophyll
temperature
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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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Alaska and PNW salmon production are out of
phase (Hare et al 1999, Fisheries)
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future climate?

• TWO STREAMS OF UNCERTAINTY
• Natural Variability (El Niño, PDO, other)
• Anthropogenic change
• Future emissions and greenhouse gas
  concentrations
• Climate system response to increased
  concentrations of greenhouse gases
• future climate change is now assessed with a
  range of models and scenarios

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Uncertainty in future climate Part 1 GG
Emissions and concentrations
IPCC Summary for Policymakers 2001
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Uncertainty in future climate Part 2 Climate
Sensitivity
Temperature Change (C)
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What might climate change look like in the
Northwest?

• We looked at 7 scenarios of future climate from
  climate models
• Averages of 7 scenarios, compared to 20th
  century
• 2F warmer by 2020s
• 4F warmer by 2050s
• slightly wetter
• Winters wetter
• Summers ???

20th century average
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Impacts of hydrologic changes

• Less snow, earlier melt means less water in
  summer
• irrigation
• urban uses
• fisheries protection
• energy production
• More water in winter
• energy production
• flooding

Natural Columbia River flow at the Dalles, OR.
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recommendations

• Consider climate as a source of habitat
  uncertainty
• develop recovery scenarios based on past climate
  records and/or future scenarios, perhaps bounded
  by best and worst cases
• Consider potential roles for stock diversity
• explore a range of functional relationships
  between habitat state and survival
• examine the importance of straying between
  different population segments

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OPI (hatchery) coho marine survival
Question WHY?
leading hypothesis changes in ocean conditions
impact the entire marine food-web
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Ocean Conditions Model hindcasts for 1948-1968
Ocean conditions appear to be an important piece
of the OPI hatchery coho story they may or may
not explain an important part of 48-68 coho
landings.
Washington-Oregon-California coho landings
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Catch in millions of coho
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OPI survival rate ()
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4
4
2
2
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The Doomsday Clock 2001
Their approach amounts to a persistence
forecast based on expectations for continued
non-replacement productivity observed in the
1985-1994 period
Wild Spawners
Brood year
1999
2020
Oosterhout and Mundy, 2001
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Hatcheries a fish is a fish
Ex smolt migration timing in wild and hatchery
coho
Spring transition date
Wild coho smolt migration
Hatchery coho releases
Mar Apr May June July
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ocean temperature deviations from
normalFebruary-April 2002