1. Freshwater Mussels of the Chehalis
Basin
F. Teal Waterstrat
USFWS

2. What is a Freshwater Mussel?
A Bivalve in the Order UNIONOIDA with a
• Complex and fascinating life history
• “Long” and sessile (stationary) adult life
• Filter feeding passion
• Highest species diversity in North America
• Great life in the Chehalis River

3. North America has ~300 of the ~850
species in the Order Unionioda

4. Typical Life Cycle
Nedeau, E. J., A. K. Smith, and J. Stone. 2009. Field Guide to the Freshwater Mussels of the
Pacific Northwest. Fish and Wildlife Service.

5. • Mussels attracting fish videos
Looks like a good snack to
a big fish!
http://www.youtube.com/
watch?v=I0YTBj0WHkU&f
eature=related

6. Salmon and Mussels
• Mussels only go where the fish go
• Everyone cares about salmon and restoring
their habitat

7. Freshwater Mussel Species in
the Chehalis Basin and PNW
Western Pearlshell Margaritifera falcata
Western Ridged Mussel
Gonidea angulata
Floaters Anodonta sp(p)

8. Western Pearlshell
Margaritifera falcata
Photo Roger Tabor USFWS

9. Photo Lee Cain Astoria High School
Juvenile Western Pearlshell Margaritifera falcata
with byssal thread

10. Photo Kevin Aitkin USFWS
Chehalis River near the Wakefield Road
Bridge near Elma, WA

11. Western Ridged Mussel
Gonidea angulata
Photo Kevin Aitkin USFWS

12. Photo Kevin Aitkin USFWS
Chehalis River near the Wakefield Road
Bridge near Elma, WA

13. Floaters
Anodonta spp.
Photo Roger Tabor USFWS

14. Photo Roger Tabor USFWSLake Quinault, WA

15. Where in the Chehalis are the Mussels?

16. • Insert Chehalis Watershed map with mussels
• Add circles to thesis sites

18. Study objectives
• Identify relative abundance, summer
distribution, and fish assemblages in the
mainstem and Upper Chehalis sub-basin
• Document presence of all species observed
(including freshwater mussels) in study area

19. Riverscape
Methods
Habitat Characteristics
• Maximum depth
• Average depth
• Wetted/bankfull width
• Substrate type
• Pool count
• Offchannel area count
• Tributary/water inputs
• Channel type

20. Non-detection

21. What Ecological Services do
Mussels Provide?
• Cleaning the Water
• Concentrating Nutrients
• System Sentinels
– Record keepers
– Bioaccumulation
– Reproduction
• Food Source

22. The Chehalis River bed just south of Elma
is covered in over 100,000 Pearlshell and a
Smattering of Ridged Mussels
Watch as mussels improve water quality…
Cleaning the Water

23. Mussels filter water
24 hours a day!

24. Old-growth of the Rivers
www.rmtrr.org
www.utmsi.utexas.edu
Concentrate Nutrients!
Record
keepers!

25. • ~300 species in North
America
• Most endangered faunal
group in North America
– 70% of the species are
imperiled or extinct
Freshwater Mussel Status
Photo by USFWS

26. Vanishing in the Northwest

27. • !
1993
2000
2012

28. Why are They Vanishing in the
Northwest?
• Urbanization
• Dams
• Host Fish
• Water Quality
• Habitat
• Invasive Species
• Restoration Projects!

29. Ohop Creek Restoration

30. What needs to be done for mussels
• Map their distribution
• Monitor the populations
• Inform the conservation agencies
• Look before you restore-de-water

31. Non Native Mussel Species

32. Zebra Mussel
(Dreissena polymorpha)
• Native to Caspian Sea and Ural River in
Asia
• 700,000 per meter2 in Great Lakes
• Cut water flow that power companies
draw from the Great Lakes
• Does not occur in Washington

33. Quagga Mussel
Dreissena rostriformis bugensis
• Native to Dneiper River drainage of Ukraine and Ponto-
Caspian Sea in Asia
• Up to 4cm in length
• First found west of Mississippi at Lake Mead in January
2007
• Found at depths up to 130 meters
• Does not occur in Washington

34. Compare:
Zebra Mussel to Quagga Mussel

35. Zebra Mussel
Invasion

36. Zebra and Quagga Mussel –
Present Distribution

37. Asian Clam
Corbicula fluminea
Photo USFWS

39. Photo Roger Tabor USFWSLake Washington, WA

40. Any Questions Before We talk about
What to Wear?