LOWER COLUMBIA RIVER ESTUARY

The Goal of this project, funded by the Army Corps of Engineers, is to assess Biocontrol Agent populations at 15 release sites made in 2005 in the Columbia River Estuary (RM 18-52).

• Lythrum salicaria occurs throughout the CR estuary
• We have shown that Lythrum salicaria has the potential to affect both the structure and function of important tidal wetlands
• Consequently, there is an interest in controlling Lythrum.
• Several groups have released biocontrol agents at multiple sites in the CR estuary.

Chris helping out with a transect, hiding in the jungle.

Quadrats arranged along four transects at a release site. Circles represent buffered distances from release site to evaluate spread of biocontrol agents.

We have found adult Galerucella at 13 of the 15 USACE release sites during 2006 and 2007. This strongly suggests that these biocontrol agent populations are becoming established (organisms need to be recovered for three years before populations are considered to be established).

We are now beginning to look at environmental factors that may favor biocontrol agent populations at some site and not others.

Reports and Publications

Dr. Fritzi Grevstad
Spartina Biocontrol Program
University of Washington
Olympic Natural Resources Center
2907 Pioneer Road
Long Beach, WA 98631

Release Summaries:

1. 1. Devils Elbow
2. 2. Dry Dock
3. 3. Eureka Bar DS
4. 4. Eureka Bar US
5. 5. Fitzpatrick IS
6. 6. Karlson IS
7. 7. Marsh IS
8. 8. Miller Sands DS
9. 9. Miller Sands US
10. 10. Mott IS
11. 11. Pillar IS DS
12. 12. Pillar IS US
13. 13. Svensen IS
14. 14. Tenasillahe IS
15. 15. Wallace IS