Generating scenarios of salmon recovery: what are the mechanisms linking climate variability to marine survival?

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Generating scenarios of salmon recovery what are
the mechanisms linking climate variability to
marine survival?

• E. Logerwell1, N. Mantua2, P. Lawson3,
• R. Francis4 and V. Agostini4

1Alaska Fisheries Science Center 2 Univ.
Washington School of Marine Affairs/Joint
Institute for the Study of the Atmosphere and
Ocean 3 Northwest Fisheries Science Center 4
Univ. Washington School of Aquatic and Fisheries
Science
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Salmon and Climate
Pacific Decadal Oscillation Index
Mantua, et al. 1997
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Oregon Production Index (OPI) Coho Salmon
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OPI Coho Survival
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Previous studies link coho survival to ...

• Upwelling (Nickelson, 1986)
• Sea surface temperature (Cole, 2000)
• Spring transition (Ryding Skalski, 1999)
• Spring and winter ocean conditions (Koslow, et
  al. in press)

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Our study of coho survival

• Select variables that represent local nearshore
  conditions
• GAM to understand effects of ocean processes on
  survival
• Examine linkages between model variables and
  climate indices

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Conceptual model
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Winter (Jan-Mar) before smolt migration
Spring (April-June)
Winter (Jan-Mar) after smolt migration
Transition
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GAM Results
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Climate linkages

• Indices
• NPI (Aleutian Low)
• PDO
• ENSO
• 1948-1997
• October-March

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NPI (Aleutian Low)
Spring upwelling
Winter SST (after)
Spring transition
Winter SST (before)
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PDO
Winter SST (after)
Spring upwelling
Spring transition
Winter SST (before)
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ENSO
Winter SST (after)
Spring upwelling
Spring transition
Winter SST (before)
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How might recovery scenarios affect salmon?

• Life stage?
• marine survival
• Habitat characteristics?
• winter SST, spring transition, spring upwelling
• Forecasts?
• climate linkages between NPI, PDO and pre-smolt
  winter SST

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Uncertainty?

• Biological dimension of ocean habitat
• Predators?
• Prey?
• Climate forecasts
• Natural variability (El Niño, PDO, other)
• Anthropogenic change

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Alternative scenarios?
Can we make a similar forecast for ocean
variables (such as SST) or climate variables
(such as NPI)?
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Beth Sinclair and Tonya Zepplin http//nmml.afsc.n
oaa.gov/AlaskaEcosystems/sslhome/Program20Review
20Presentations/Program20Review.htm
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