Hydrilla
Quick Facts |
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Scientific name | Hydrilla verticillata |
Origin | Southeast Asia |
Introduction | Early 1950s, aquarium trade |
Aquatic community | Submersed, surface mats |
Habitat | Inches to 35 feet deep |
Distribution | Statewide |
Management effort | Eradicate new infestations Maintenance control of established plants |
2017 public waters / plant acres | 172 (37%) / 22,166 |
2017 Waters / acres controlled | 105 / 26,502 |
Management Options |
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Biological | Sterile grass carp stocked in about 100 public lakes; 4 host-specific insect species released with few successes; FWC is not currently funding overseas exploration for additional host-specific insects |
Chemical | Large-scale: potassium endothall, diquat, bispyribac, fluridone, penoxsulam; topramezone – small-scale: copper, diquat – research is focusing on combinations of herbicides, especially contact type herbicides with systemics |
Mechanical | Harvest from spring runs and boat trails in deep water, harvest or shred mats lodged against structures (bridges, dams) |
Physical | Hand pull / diver dredge new infestations, or in fast-flowing water |
Environmental and Economic Concerns
- Stems can elongate as much as 6-8 inches per day in Florida’s peak growing season
- Can cover entire water body surface 1-2 years after introduction
- 80% of plant mass is in the upper two feet of water column
- blocks sunlight and shades out native plants
- blocks air exchange and consumes oxygen, leading to fish kills
- blocks access, navigation, and recreation
- breaks loose and jams against bridges and dams
- Reduces recreation-based incomes and property values
- Doubles sedimentation rate from senescing leaves and stems
- Disperses by fragments, buds, and runners (does not produce seeds)
- Resists long-term control via underground propagules (tubers)
- millions produced per acre
- no effective tuber control method
- viable tubers lie dormant for as long as seven years
DOWNLOAD
FWC Hydrilla Management Position (PDF)
FWC Hydrilla Management Position Background Information (PDF)
Florida Fish & Wildlife Conservation Commission, Status of the Aquatic Plant Maintenance Program in Florida Public Waters, Annual Report – Fiscal Year 2016-2017.