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

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. • 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. Redorbit.com!BRANDON COLE / WWW.BRANDONCOLE.COM!
Forage fish provide multiple ecosystem services globally

4. The mysterious decline of "
Puget Sound herring"

6. Forage fish support iconic Puget Sound species

7. 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

8. Puget Sound herring are tightly
linked to the shoreline
Paul Hanson, NOAA

9. Map: Blake Feist, NOAA NWFSC
Puget
Sound
Shoreline
Armoring

10. Shoreline armoring is
increasing.
Does population diversity
increase stability of Puget Sound herring?

11. Mid/small cap stocks
Large cap stocks
Balanced fund
Cash
The Portfolio Effect: Diversity increases stability

12. 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

13. Herring subpopulations can contribute 2-5x the average in good years.

14. Puget Sound herring subpopulations are not highly synchronous

15. The Puget Sound herring population is less variable than
the individual subpopulations
Biomass(standardized)
1980 2010

16. 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

17. 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

18. Are Puget Sound herring habitat limited?

19. 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

20. Thanks!
tessa@uw.edu
@tessafrancis