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Aquatic Pesticide Monitoring Program. Non-Chemical Aquatic Plant Control A New Research Program Nicole David Ben K. Greenfield Geoff Siemering. Aquatic Pesticide Monitoring Program Background Increased permitting requirements for chemical pesticide application after Talent decision
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Aquatic Pesticide Monitoring Program Non-Chemical Aquatic Plant Control A New Research Program Nicole David Ben K. Greenfield Geoff Siemering
Aquatic Pesticide Monitoring Program • Background • Increased permitting requirements for chemical pesticide application after Talent decision • Increased costs for pesticide permitting: reevaluate control methods • Specified in SWRCB/Waterkeepers legal settlement • Chemical monitoring program • Non-chemical alternatives program
Chemical Program Objectives • Gather basic sampling data for SWRCB • Refine sampling, analytical, and toxicity • protocols • Identify and fill gaps in pesticide knowledge • base • Develop monitoring plan handbook
Pesticide User Groups 1. Irrigation supply systems 2. Drinking water reservoirs 3. Exotic weed control (canals and coastal) 4. Mosquito abatement 5. Flood and storm water control 6. Recreational impoundments (golf courses, parks, etc)
Target Aquatic Pesticides Selected by Science Advisory Committee based on toxicity and extent used. • Copper sulphate • Acrolein • Glyphosate • Fluridone • Methoprene • Diquat dibromide • Malathion • 2,4-D • Triclopyr
Monitoring Techniques • Chemical Monitoring • Water • Sediment • Porewater • Tissue • Toxicity Testing • Water: EPA 3 species • Sediment: H. azteca • Tox TIE (by tox labs) • Water Quality Parameters • Conductivity, pH, Temp., TSS, Alkalinity, [Ca], [Mg], [Na], DOC, DO, Hardness • Sediment Quality Parameters • Grain size, Nitrate, % solids, TN, TOC, SEM-AVS (for Cu sites)
Non-Chemical Alternatives Program Objectives 1. Conduct thorough cost-effectiveness evaluations of non-chemical aquatic plant control options 2. Identify additional non-chemical methods for CA waters 3. Produce guidebook to help managers determine best control options
Identify additional non-chemical approaches • for California waters • Interviews with weed-control experts nationwide to make sure CA isn't missing out on effective methods • Demonstration Projects with potentially promising methods for specific water body types
Available Methods • Biological methods • Insects • Grass Carp • Physical methods • Mechanical Harvesting and Cutting • Rotovation • Weed Rollers • Suction Dredging • Bottom Barriers • Manual Removal • Water Drawdown • Sediment Excavation/Chaining
Biological Control • Sterile Grass Carp • Feeds on aquatic plants • Non-selective • Works best in small ponds • Insects • Reduce plant growth and seed production • Establishment might be difficult • Plant specific
Mechanical Control • Mechanical Harvesting/ Mechanical Cutting • Cuts plants several feet below water surface • Immediate but short-term results • Impact on fish and invertebrates • Risk of spreading invasive plants
Rotovation • Barge-mounted rototilling machine • Dislodges plant root crowns Weed Rollers • Metal cylinder attached to dock • Rolls in 270 degree arc • Compresses plants and soil • Disturb bottom dwelling organisms • and fish
Suction Dredging • Diver-operated pump system • Suction plants and roots from sediment • Plant material is collected on the boat • Slit curtain can be used to control • turbidity Bottom Barriers • Semi-permanent materials laid over plant bed • Eliminate sunlight • Loss of habitat for benthic organisms
Manual Removal • Removes entire root crown • Labor intensive • Water Level Drawdown • Dewatering water body by releasing water via • dam or weir or pump • Requires water level control structures • Excavation • Removes plants and surface sediment • Viable for storm water and irrigation canals • Increased turbidity downstream
Preliminary Interview results • Results from interviews with experts from 11 states in draft Technical Memo • California is in the loop. Most available approaches and technologies have been attempted in California waters • Method improvements have mostly been restricted by a lack of funding.
Mechanical Shredding Demonstration Projects Mechanical shredding without removal • Comparing to chemical treatment at similar location and control site • Cost effectiveness comparison • Invertebrate community bioassessment • Impact on water chemistry • Possibility of trace metal analysis
Demonstration Projects • Preliminary plan - Mechanical shredding of water hyacinth (Eichhornia crassipes) in Delta sloughs.
Demonstration Projects • Fish Study Objectives • Direct measurements of water chemistry before • and after mechanical harvesting operations. • Quantification of removed fish and fish species.
Deliverables • First Year’s Summary Report already available. • Phase 2data analysis and report for chemical project: • Beginning of 2004 • Data analysis and report for non-chemical • demonstration projects • Mechanical Shredding: Mid 2004 • Fish Study: Beginning of 2004 • Conclusion • In many weed management situations a mix of • techniques, possibly including non-chemical and • chemical methods will be the most appropriate approach.