# Presentation: 357488

## Developing quantitative tools to forecast to forecast the effects of climate variability on the population dynamics of Pacific salmon

**Developing quantitative tools to forecast to forecast the effects of climate variability on the population dynamics of Pacific salmon**

**Rich Zabel & Mark Scheuerell**
**Northwest Fisheries Science Center**
**Nate Mantua**
**University of Washington**

## Forecasting climate impacts on salmon

- Atmosphere

- Smolts

- Adults

- Smolts

- Adults

- Eggs

- Parr

- Ocean

- Freshwater

**Notes:**
In order to generate better predictions about the potential impacts of climate change on Pacific salmon, we are collaborating with the UW Climate Impacts Group to develop a model framework whereby we use future greenhouse gas scenarios and global circulation models to drive changes in atmospheric processes and alter both the marine and freshwater environments (e.g., SST, upwelling, streamflows), with subsequent effects on various stages of the salmon life cycle. 

## West Coast Upwelling Index Trends

- There are large positive trends from 1946-2004 in the regionally averaged upwelling index for the S CCS in spring and the S CCS and N CCS in summer.
- From Mantua and Mitchell, in prep.

***St. devs/100 years***

**Notes:**
There are large positive trends in the regionally averaged upwelling index for the S CCS in spring and the S CCS and N CCS in summer. 
There are weaker negative trends from SEAK/BC to the S. Cal Bight in winter, and weak positive trends in fall at all locations. 

## A 100+ year perspective on spring upwelling

- A 107 year springtime upwelling index for 42-48N shows strong interannual to interdecadal variability, without a large linear trend
- (Correlation with the PDO index is -0.56)
- Mantua and Mitchell, in prep.

**Notes:**

Correlations between the April-May-June upwelling index and April-May-June average climate indices -- UI is the averaged Bakun index for 42-48N; SLP_UI is a sea level pressure based upwelling index for 42-48N; 
          SLP_UI   UI   Nino   NOI  PDO  EP-NP  PNA   SST
SLP_UI   100      77   -33     52     -56     5         -61     -47

## Spring/Summer Chinook Salmon

- “Stream type” life history

- Adults return to spawn & die in April-July (year *t*)

- Parr emerge and rear in creeks & rivers (year *t*+1)

- Smolts emigrate in April-June (year *t*+2)

- Adults at sea
- (years *t*+3 to *t*+6)

- freshwater

- ocean

**Notes:**
Spring/summer Chinook salmon from the Snake River basin have a unique life history that makes them susceptible to a variety of natural and human impacts, but also allows us to study them in some detail.  Describe the life history...

## Columbia R.

- Snake R.

- OR

- ID

- NE Pacific

- WA

- BC

**Notes:**
The story I’m going to tell you about today revolves around salmon from the Columbia River basin located right here in our backyard.  In particular, I’m going to concentrate on a stock of chinook salmon from the Snake River basin located in eastern WA, OR, and ID.

In the Pacific Northwest, a large number of salmon population have been faced a whole suite of anthropogenic insults.

## An ocean-climate effect?

- SAR (%)

- Regime
- shift

- Regime
- shift

## Time series of the CUI

- m3 seawater / 100 m shoreline / sec

- April

- October

**Notes:**
Two representative times series of the coastal upwelling index (CUI) for the spring (April, top) and fall (October, bottom) transition periods.

## Forecasts of climate-related survival

- Scheuerell, M. D., J. G. Williams. 2005. Forecasting climate-induced changes
- in the survival of Snake River spring/summer Chinook salmon.
- Fisheries Oceanography, 14(6):448-457.

## Responses to Climate Change 

- Climate effects multiple life stages
- Need to consider changes in context of entire life cycle

## Slide 11

## Another point: terrestrial and marine ecosystems will have much different responses

- Marine – slower rate of warming, very complex response
- Terrestrial – faster rate of warming, potentially much more predictable

## General approach for predicting effects of climate change

- Examine response of life stage-specific survival rates to current climate variability
- Develop predictive models of how climate conditions will change in future
- Predict how life stage-specific survival will change with climate change
- Incorporate predictions into Population Viability Model to predict changes in population viability in response to climate change

## General approach for predicting effects of climate change

- Examine response of life stage-specific survival rates to current climate variability
- Develop predictive models of how climate conditions will change in future
- Predict how life stage-specific survival will change with climate change
- Incorporate predictions into Population Viability Model to predict changes in population viability in response to climate change

## General approach for predicting effects of climate change

- Examine response of life stage-specific survival rates to current climate variability
- Develop predictive models of how climate conditions will change in future
- Predict how life stage-specific survival will change with climate change
- Incorporate predictions into Population Viability Model to predict changes in population viability in response to climate change

## General approach for predicting effects of climate change

- Examine response of life stage-specific survival rates to current climate variability
- Develop predictive models of how climate conditions will change in future
- Predict how life stage-specific survival will change with climate change
- Incorporate predictions into Population Viability Model to predict changes in population viability in response to climate change

## Ocean Conditions

**Ocean Conditions**

## Spawners

**Spawners**

**Parr**

**Smolts**

**Estuary**

**Early ocean**

**Ocean**

**Climate**

**Density**
**Dependence**

- Zabel, Scheuerell, Mclure and Williams. 2006.
- Conservation Biology 20: 190-200.

- Stochastic life-cycle
- model for Snake River
- Sp/Su Chinook salmon

## Third-year (ocean) survival strongly related to the 

- Third-year (ocean) survival strongly related to the
- Pacific Decadal Oscillation (PDO)

## Effects of Ocean Conditions

- _Effects of Ocean Conditions_

**Predicted**

## Effects of Ocean Conditions

- _Effects of Ocean Conditions_

- “Historic”
- conditions
- 1900-2000

**Predicted**

## Effects of Ocean Conditions

- _Effects of Ocean Conditions_

- “Bad”
- conditions
- 1977-1997

**Predicted**

## Effects of Ocean Conditions

- _Effects of Ocean Conditions_

- Historic Ocean
- Bad Ocean

## Effects of Ocean Conditions

- _Effects of Ocean Conditions_

- Historic Ocean
- Bad Ocean

- Prob [falling below 3100 spawners]:
- Historic Ocean: 0.496
- Bad Ocean: 0.880

## Effects of Ocean Conditions

- _Effects of Ocean Conditions_

- Historic Ocean
- Bad Ocean

- Mean Spawners:
- Historic Ocean: 61,500
- Bad Ocean: 19,500

## Conclusions

- Ocean conditions have huge effects on salmon population dynamics
- Must consider uncertainty in future ocean climate in viability analyses

## Freshwater Climate

**Freshwater Climate**

## Freshwater Climate Questions:

- 1) Is juvenile survival related to freshwater climate indicators?
- 2) What is the spatial scale of the climate response?
- Crozier and Zabel.  2006.  Climate impacts at multiple scales: evidence for differential population responses in juvenile Chinook salmon.  Journal of Animal Ecology 75: 1100-1109

## Salmon River basin Chinook salmon: 15 streams, 12 years

## Estimating parr-to-smolt survival

- Fish tagged
- as parr ...

- ... and then
- detected as
- migratory smolts

## C3

**C3**

**C4**

**C1**

**C2**

- distance

## Survival

- Summer air temperature (oC)

- Flow (m3/hr)

- Summer stream temperature (oC)

- Flow (m3/hr)

**C1**

**C2**

**C4**

**C3**

## CAPE HORN CREEK

## CAPE HORN CREEK

**C2**

- Flow (m3/hr)

- Survival

## BIG CREEK (LOWER)

## BIG CREEK (LOWER)

- Survival

- Summer stream temperature (oC)

## Conclusions

- Differential response of populations to freshwater climate
- Response mediated by habitat conditions

## Changes in Salmon River basin  climate

- Changes in snowpack one of the most predictable climate indicator in response to climate change

## Snowpack has a strong effect on the hydrograph

- Flow

- JAN

- DEC

- Snowfall dominated
- system

## Snowpack has a strong effect on the hydrograph

- Flow

- JAN

- DEC

- Less snow and
- More rain

## Effects of freshwater climate change on population viability of Salmon River basin Chinook

- Crozier, Zabel, and Hamlet (UW CIG). *In Press*. Predicting differential effects of climate change at the population level with life-cycle models of spring Chinook salmon. *Global Change Biology*.

## Global models must be downscaled for regional studies

- CIG is undertaking a new effort to downscale IPCC climate change scenarios for the PNW region at 1/16 degree resolution.
-  temperature
-  precipitation
-  streamflow
- In a related effort, they are using global and regional sea level pressure fields to evaluate projected climate change impacts on coastal upwelling.

**Notes:**
Global climate models are designed to simulate the large-scale patterns of climate, and they do so quite well (globe, the surface air temperature simulated by the German ECHAM5 model for January 1999).  The ECHAM5 model in this simulation had a resolution of approximately 2°longitude by 2°latitude. For smaller-scale studies, however, the graininess of the models is evident (top right) and important features are missing like the east-west contrast across the Cascades.  The process of translating these large-scale fields to the fine-scale topography (0.125° by 0.125° in the example shown) is called “downscaling”.  The next slide describes the two primary approaches to downscaling.

## Mean October flow (cms)

## Mean June Temperature (oC)

- Mean June Temperature (oC)

## Climate scenario

**Temp. (****o****C)**

**Flow (cms)**

**Climate scenario**

**Climate scenario**

## Slide 46

## Climate scenario

- (Loon, Big, Marsh Creeks)

- Mean spawner abundance (SFSR)

## Slide 48

## Conclusions

- Potentially very strong response of Salmon River Basin salmon populations to climate change

## Conclusions

- But, among population diversity in response to climate may act as a buffer against the impacts of climate change

## Future Directions

- Ocean/Freshwater climate interactions
- Expand geographic scale of freshwater climate-change impacts
- Freshwater climate indicators