Presented at the TWCA Fall Conference 2014 www.twca.org

1. Aquatic Vegetation
Management in Texas
EEaarrll WW.. CChhiillttoonn IIII,, PPhh..DD..

2. AAqquuaattiicc IInnvvaassiivvee PPllaannttss CCaann CCaauussee
SSiiggnniiffiiccaanntt PPrroobblleemmss
Water hyacinth Hydrilla
Giant salvinia
Giant Reed

3. Approximately 110
public water bodies
(Dots denote infested public
reservoirs)
45,000 – 80,000 acres
Hydrilla
Matted
Hydrilla Hydrilla Tubers

4. Lake Austin hydrilla
- Clogs intakes
- Interrupted power generation, July/August 2002
- Currently has virtually no hydrilla

5. Water hyacinth
Approximately 35 public
water bodies
(Dots denote infested public
reservoirs)
6,000 - 14,000 acres
Mouth of the Rio
Grande
Main Channel of the
Rio Grande

6. Giant salvinia
Salvinia molesta
6,000-18,000 acres
Toledo Bend
Spread from 1-23
water bodies in 15
years
Caddo Lake
Mature giant
salvinia

7. Giant Salvinia Growth
Lake Kariba, Africa – Giant salvinia expanded to
cover 250,000 acres in three years

8. Giant Salvinia Growth
Sepik River (Papua, New Guinea) - Grew to cover 96
square miles in eight years (1972-1980)

9. Giant Salvinia Growth
Doubling time:
Greenhouse 2.2 days
Sterile culture lab 3.4 days
Lake Kariba 8.1 days
Optimum temperature 30 °C (86 °F)
Temperature range 10°C (50 °F) –
40 °C (104 °F)

10. Giant ssaallvviinniiaa aanndd TToolleeddoo BBeenndd
RReesseerrvvooiirr

15. GGiiaanntt ssaallvviinniiaa aanndd CCaaddddoo LLaakkee

17. Management Options
Biological
Control
Giant salvinia
weevil
Booms
Yes1
Herbicide
Bispyribac,
Diquat,
Flumioxazin
Fluridone,
Glyphosate
Penoxsulam
Water level
manipulation
Yes
Cyrtobagous salviniae
Richard Chan

18. Toledo Bend & Caddo Lake
• Estimated Combined Acreage of 13,000 to
15,000 acres of giant salvinia
• Herbicide Treatment Costs: $65-100 per acre

19. $ Mil

20. Yellow Floating Heart
Nymphoides peltata

21. Yellow Floating Heart
Lake Moss

22. Thank
You!