Transcript Aquatic Plant Management Options for Caddo Lake

Aquatic Plant Management
Options for Caddo Lake
Timothy J. Bister
Texas Parks and Wildlife Department
Inland Fisheries District 3A
Marshall, Texas
Plan Objectives
• Establish long-term management of
nuisance aquatic plants in Caddo Lake
• Maintain a healthy lake ecosystem
• Protect native aquatic habitat
• Maintain access for users
Problematic Species
• Waterhyacinth
• Hydrilla
• Giant salvinia
Mechanical Harvesters
• Limited to water >2 feet deep with few
stumps
• Past experience has proven ineffective
and cost prohibitive
Triploid Grass Carp
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Effective for control of hydrilla
Not effective for waterhyacinth
Not considered a viable control for giant salvinia
Will eat native species
Would require emigration barrier
Would require agreement between TX & LA
Recommendations
• Giant salvinia
– Conduct herbicide treatments
• Glyphosate/Diquat mixture
– Physical removal/disposal by
trained/permitted volunteers
– Increase public awareness through signs,
flyers, and news releases
– Release giant salvinia weevils in areas that
become uncontrollable with herbicide
– Conduct annual aquatic vegetation surveys
to monitor giant salvinia coverage
Recommendations
• Waterhyacinth
– Continue herbicide treatments
• 2,4-D
• WMA, boat ramps, other access
• Supplemental efforts from other entities fully
supported
– Conduct annual surveys (Aug/Sep) to
monitor coverage of waterhyacinth
Recommendations
• Hydrilla
– Maintain critical boat lanes restricted by
hydrilla with herbicide
– Not most critical problem at this time
– Assess hydrilla coverage during annual
aquatic vegetation surveys
Recommendations
• Create on-site vegetation control crew
– May to October
– Hire private herbicide applicator
• Pursue additional funding
– Support spray crew
– Purchase herbicide
• Develop long-term plan