1. Aquatic Plant Management Options for Caddo Lake Timothy J. Bister Texas Parks and Wildlife Department Inland Fisheries District 3A Marshall, Texas

2. 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

3. Problematic Species Waterhyacinth Hydrilla Giant salvinia

4. Mechanical Harvesters Limited to water >2 feet deep with few stumps Past experience has proven ineffective and cost prohibitive

5. Triploid Grass Carp 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

6. 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

7. 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

8. 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

9. 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