1. “Salvinia molesta. Infestation in the Lower Colorado River.” Presents: Oscar H. Torres U. University of Arizona Department of Soil, Water and Environmental Science. Aquatic Plants Course, SWES 525.

2. Antecedents. Mitchell (Giant salvinia). Mitchell (Giant salvinia). Brazilian native, free floating aquatic fern. Brazilian native, free floating aquatic fern. Reproduces by vegetative fragmentation. Reproduces by vegetative fragmentation.

3. History 1999 USFWS discovered S. molesta within the Cibola National Wildlife Refuge. 1999 USFWS discovered S. molesta within the Cibola National Wildlife Refuge. Other reports as South as Yuma, AZ. Other reports as South as Yuma, AZ. Origin: Irrigation outfall drain (Palo Verde Irrigation District, [PVID]). Origin: Irrigation outfall drain (Palo Verde Irrigation District, [PVID]).

4. Adverse effects Blocks water system’s intakes and outlets. Blocks water system’s intakes and outlets. Ecology & Economy: Ecology & Economy: Limiting free water space (Recreation). Usurping in situ vegetation. Increasing anoxic conditions (Fishery).

5. Infested Sites

6. Lower Colorado River Giant Salvinia Task Force Bureau of Reclamation. Bureau of Reclamation. Bureau of Land Management. Bureau of Land Management. Fish and Wildlife Service. Fish and Wildlife Service. Department of Agriculture. Department of Agriculture. PVID. PVID. Other local, State, and Mexican Agencies. Other local, State, and Mexican Agencies.

7. Objective Eradicating or controlling S. molesta along PVID and Lower Colorado River (LCR). Eradicating or controlling S. molesta along PVID and Lower Colorado River (LCR). Integral Action Plan Physical control. Chemical spray applications. Biological control. Public information.

8. Physical Removal (PR). -Nets. -Nets. -Excavation. -Excavation. -Booms. -Booms. -Skimmer. -Skimmer.

9. PR Advantages: Advantages: Non polluting. Non polluting. Disadvantages: Disadvantages: Expensive and effort consuming. Expensive and effort consuming. Complete removal was not usually achieved (native flora). Complete removal was not usually achieved (native flora).

10. Chemical applications (CA). Chelated Copper 10% to 15% Solution. (Clearigate, Komeem). Chelated Copper 10% to 15% Solution. (Clearigate, Komeem). Diquat-Glyphosate Mixture 15% diquat-5% glyphosate Solution, and Surfactant. Diquat-Glyphosate Mixture 15% diquat-5% glyphosate Solution, and Surfactant. Diquat alone. Diquat alone.

11. CA. Fluridone. Fluridone. Diquat dibromide and Surfactant. Diquat dibromide and Surfactant. Glyphosate and Surfactant. Glyphosate and Surfactant.

12. CA

13. CA Advantages Advantages Effective on eradicating plants. Effective on eradicating plants.

14. CA (Disadvantages) Could copper levels. Could copper levels. Glyphosate and diquat have { } use in waters with sediments. Glyphosate and diquat have { } use in waters with sediments. Copper based, { } where fauna resides, & where = CO 3 > 50 ppm. Copper based, { } where fauna resides, & where = CO 3 > 50 ppm. Non substrate specific. Non substrate specific. Polluting. Polluting. Expensive & Effort consuming. Expensive & Effort consuming.

15. Biological Control (BC). Cyrtobagous salviniae weevils. Cyrtobagous salviniae weevils. 2001 USDA approved tests on biocontrol. 2001 USDA approved tests on biocontrol. 2003 USDA approved release at LCR. 2003 USDA approved release at LCR.

16. BC. From 2003 to 2005 weevils controlled salvinia population where applied. From 2003 to 2005 weevils controlled salvinia population where applied. Weevils need + time. Weevils need + time. + investigation to conclude if weevils are successful in long spans. + investigation to conclude if weevils are successful in long spans.

19. BC Advantages Advantages Species specific. Species specific. + Effective in stagnant waters. + Effective in stagnant waters. Inexpensive. Inexpensive.

20. BC Disadvantages Disadvantages - Ineffective during winter (~5° C). - Ineffective during winter (~5° C). - Ineffective on waters. - Ineffective on waters.

21. Public Education and Outreach

22. Throughout 2006 August: Biocontrol monitoring continues along LCR: 3000 weevils/m 2. August: Biocontrol monitoring continues along LCR: 3000 weevils/m 2. October: Diquat & glyphosate application: October: Diquat & glyphosate application: @ Estes & Browns drain (salvinia present). Spraying as salvinia disappeared. Spraying as salvinia disappeared.

23. Conclusions & propositions The integrated approach solution has reached the results. The integrated approach solution has reached the results.

24. Conclusions & propositions BC: research on larvae. 3 years of continual evaluation. BC: research on larvae. 3 years of continual evaluation. Reclamation procedures: successful in stagnant waters Reclamation procedures: successful in stagnant waters

25. Conclusions and proposals Perhaps curbed salvinia: natural conditions Perhaps curbed salvinia: natural conditions limited nutrients turbulencetemperature Removal of 90-95% @ PVID. Removal of 90-95% @ PVID. Removal on river: total (natural conditions?) Removal on river: total (natural conditions?)