1. The Influence of Salmon
Recolonization on Riparian
Communities in the Cedar River,
Washington.
Jessie Moravek
Northwestern University 2016
Environmental Science/Biology
1
Healthy Oceans
Northwest Fisheries Science Center
Dr. Peter Kiffney
Photo: H.Clipp 1

2. Outline
• Background
• Objective
• Methods
• Results
• Conclusion
• Future Studies
• Acknowledgements
2
Photo: J.Hall

3. Seattle
3

4. Coho Fry
Stonefly
Larvae
Mayfly
Larvae
Caddisfly
Larvae
Nutrients Food
Salmon CarcassAlgaeTerrestrial Inputs 4
Photos:J.Hall,H.Clipp,G.Rawley

5. Spider
Riparian Vegetation
Spider
Prey
Falling
Input
Nutrients
Emergence
Bear
Osprey
Aquatic Ecosystem 5Photos: H. Clipp, R.Barth, F.Vollrath

6. Objective:
Investigate the effects of salmon
re-colonization on the riparian community
in the Cedar River
6
Photo: J.Hall 6

7. Hypothesis
Higher
Salmon
Inputs
Increased
aquatic insect
diversity and
density
Increased prey
diversity and
density
Increased spider
diversity and
density
7Photos: J.Hall, F.Vollrath

8. Field Methods
1. Salmon: Estimated salmon
carcasses per m2 of river
habitat
2. Aquatic Insects: Surveyed
aquatic insects in 0.1 m2
quadrats (4 per reach)
3. Prey: Collected and
identified prey in spider
webs within ten meter
transects (2-4 replicates
per reach)
4. Spiders: Surveyed and
identified spiders and
webs within one meter of
water along ten-meter
transect (2-4 per reach)
8Photos: H.Clipp

9. 9
Data Analysis
• Aquatic insects, prey, and spiders:
• Shannon Wiener diversity
• Taxa richness
• Density
• Regression analysis
• p < 0.05
9Photos: H.Clipp

10. Results
Higher
Salmon
Inputs
Increased
aquatic insect
density
Increased prey
density
Increased spider
diversity
Distance from the dam (km)
0 5 10 15 20
Salmonbiomassinput(kg/m
2
)
0.000
0.005
0.010
0.015
0.020
0.025
0.030
y = 0.03 - 0.004*km +
0.001*km2
R2
= 0.86
10Photos: J.Hall, F.Vollrath

11. 11

12. Results
Higher
Salmon
Inputs
Increased
aquatic insect
density
Increased prey
density
Increased spider
diversity
12Photos: J.Hall, F.Vollrath

13. 13

14. Results
Higher
Salmon
Inputs
Increased
aquatic insect
density
Increased prey
density
Increased spider
diversity
14Photos: J.Hall, F.Vollrath

15. Results
Higher
Salmon
Inputs
Increased
aquatic insect
density
Increased prey
density
Increased spider
diversity
15Photos: J.Hall, F.Vollrath

16. Results
Higher
Salmon
Inputs
Increased
aquatic insect
density
Increased prey
density
Increased spider
diversity
?
18Photos: J.Hall, F.Vollrath

17. 19

18. Summary
Higher
Salmon
Inputs
Increased
aquatic insect
density
Increased prey
density
Decreased spider
diversity
20Photos: J.Hall, F.Vollrath

19. 19
Conclusions
• Significant relationships exist between salmon
inputs, aquatic invertebrates, spider diversity, and
spider prey.
• Indicate connections between aquatic and riparian
ecosystems on the Cedar River
• Important for understanding widespread
implications of salmon re-colonization and
management.
Photo: H.Clipp 21

20. Future Studies
Experimentally clarify relationships
between salmon, aquatic
invertebrates, and spiders
20
22

21. Peter Kiffney
Tom Good
Hannah Clipp
21
Acknowledgements
Photo: T.Good 23

22. Citations
• Kiffney, P.M., et al. Changes in fish communities following recolonization
of the Cedar River, WA, USA by Pacific salmon after 103 years of local
extirpation. River Research and Applications 2009. 25: 438-452.
• Kiffney, P.M., et al. Linking resource availability and habitat structure to
stream organisms: an experimental and observational assessment.
Ecosphere 2014. 5(4):39.
• Pess, G.R, et al. "The Influences of Body Size, Habitat Quality, and
Competition on the Movement and Survival of Juvenile Coho salmon
During the Early Stages of Stream Recolonization." Transactions of the
American Fisheries Society 2011. 140:4, 883-897.
• R Core Team (2014). R: A language and environment for statistical
computing. R Foundation for Statistical Computing, Vienna, Austria. URL
http://www.R-project.org/.
24

23. Questions
23
Photo: T.Good 24