Population diversity in Puget Sound herring:
Is there a “portfolio effect”?
Tessa Francis, University of Washington Tacoma...
•  Pacific herring in Puget Sound are declining, causes unknown.
•  21 different sub-populations, associated with shorelin...
Redorbit.com!BRANDON COLE / WWW.BRANDONCOLE.COM!
Forage fish provide multiple ecosystem services globally
The mysterious decline of "
Puget Sound herring"
Forage fish support iconic Puget Sound species
Puget Sound herring have declined in recent decades
0
3,000
6,000
9,000
12,000
15,000
18,000
1973 1978 1983 1988 1993 1998...
Puget Sound herring are tightly
linked to the shoreline
Paul Hanson, NOAA
Map: Blake Feist, NOAA NWFSC
Puget
Sound
Shoreline
Armoring
Shoreline armoring is
increasing.
Does population diversity
increase stability of Puget Sound herring?	
  
Mid/small cap stocks
Large cap stocks
Balanced fund
Cash
The Portfolio Effect: Diversity increases stability
1	
  
2	
  
3	
  
Age	
  diversity	
  
0.01
0.1
1
10
1
Major	
  rivers	
  
0.01
0.1
1
10
1
Streams	
  
0.01
0.1
1
10
1
All...
Herring subpopulations can contribute 2-5x the average in good years.
Puget Sound herring subpopulations are not highly synchronous
The Puget Sound herring population is less variable than
the individual subpopulations
Biomass(standardized)
1980 2010
Log(Variance)
Log(Mean)
z = 2.1
expected
observed
The Puget Sound herring population is two times more reliable than
the i...
No	
  change	
  
Decrease	
  
Increase	
  
Eelgrass	
  bed	
  trends	
  (2004-­‐2009)	
  	
  
33%	
  of	
  	
  
shoreline	...
Are Puget Sound herring habitat limited?
Marc Mangel Tim Essington
Alec MacCall Doug Hay
Paul Hershberger Dayv Lowry
Ole Shelton Tessa Francis
Study Panel on Ecosy...
Thanks!
tessa@uw.edu
@tessafrancis
Portfolio Effect in Puget Sound Herring: ESA 2013 Minneapolis
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Portfolio Effect in Puget Sound Herring: ESA 2013 Minneapolis

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Stability of Pacific herring in Puget Sound is 2x what it would be without habitat and population diversity.

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Portfolio Effect in Puget Sound Herring: ESA 2013 Minneapolis

  1. 1. Population diversity in Puget Sound herring: Is there a “portfolio effect”? Tessa Francis, University of Washington Tacoma Megsie Siple, University of Washington Daniel Schindler, University of Washington Washington Department of Fish and Wildlife
  2. 2. •  Pacific herring in Puget Sound are declining, causes unknown. •  21 different sub-populations, associated with shoreline sections. •  Shoreline armoring is increasing. •  Do we increase stability of the population by keeping all sub-populations? YES THERE IS A PORTFOLIO EFFECT ✔
  3. 3. Redorbit.com!BRANDON COLE / WWW.BRANDONCOLE.COM! Forage fish provide multiple ecosystem services globally
  4. 4. The mysterious decline of " Puget Sound herring"
  5. 5. Forage fish support iconic Puget Sound species
  6. 6. Puget Sound herring have declined in recent decades 0 3,000 6,000 9,000 12,000 15,000 18,000 1973 1978 1983 1988 1993 1998 2003 2008 2013 2018 TONS YEAR Cherry Pt. Squaxin Adult spawner biomass Based on egg deposition surveys Source: WA Department of Fish and Wildlife
  7. 7. Puget Sound herring are tightly linked to the shoreline Paul Hanson, NOAA
  8. 8. Map: Blake Feist, NOAA NWFSC Puget Sound Shoreline Armoring
  9. 9. Shoreline armoring is increasing. Does population diversity increase stability of Puget Sound herring?  
  10. 10. Mid/small cap stocks Large cap stocks Balanced fund Cash The Portfolio Effect: Diversity increases stability
  11. 11. 1   2   3   Age  diversity   0.01 0.1 1 10 1 Major  rivers   0.01 0.1 1 10 1 Streams   0.01 0.1 1 10 1 All  the  same  age   0.01 0.1 1 10 1 year   Total  return  (rela;ve)   Bristol  Bay   1960                                        2010  
  12. 12. Herring subpopulations can contribute 2-5x the average in good years.
  13. 13. Puget Sound herring subpopulations are not highly synchronous
  14. 14. The Puget Sound herring population is less variable than the individual subpopulations Biomass(standardized) 1980 2010
  15. 15. Log(Variance) Log(Mean) z = 2.1 expected observed The Puget Sound herring population is two times more reliable than the individual components of the portfolio Anderson et al. Methods Ecol. Evol. In Press
  16. 16. No  change   Decrease   Increase   Eelgrass  bed  trends  (2004-­‐2009)     33%  of     shoreline   altered   25%  of     shoreline   armored   2005-­‐2010   Rate  of  new   armoring:   1.8  km/yr  
  17. 17. Are Puget Sound herring habitat limited?
  18. 18. Marc Mangel Tim Essington Alec MacCall Doug Hay Paul Hershberger Dayv Lowry Ole Shelton Tessa Francis Study Panel on Ecosystem Based Management of Puget Sound Forage Fish 1.  Status and trends 2.  Key Vulnerabilities 3.  Ecosystem Needs
  19. 19. Thanks! tessa@uw.edu @tessafrancis

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