Download Chemical Treatment of Ponds and Lakes

Chemical Treatment of Ponds and Lakes
Integrated Lakes Management
Rich Daly & Sarah Denny
A peak in the pond management “tool box”
• Chemical applications
• Bacteria and Enzyme applications
• Alum applications
• Pond dye applications
• Aeration installation
• Sediment removal
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Shoreline restoration
Native plantings
Wildlife control
Manual removal
Community education
The Good and The Bad
Why Chemical Applications are good:
1. Control invasive species
2. Cost effective
3. Quick results
Why Chemical Applications are bad:
1. Overused and misused
2. Leads to unrealistic expectations
3. Can be environmentally harmful
Chemical Treatment
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Problem and Solution Identification
Plant ID
Chemical Selection
Application
Monitoring
Step #1
What is the problem?
What is the solution?
• Chemical treatment?
– Only if other options don’t work or aren’t practical
– Only in conjunction with other management techniques
– only when appropriate to solve the problem
• Nutrient reduction?
• Light limitation? • EDUCATION
Step #3
Plant Identification
• THE MOST IMPORTANT STEP
• Hundreds of algal species
– Several of which are copper‐resistant
• Dozens of common aquatic plants
– Several different morphological characteristics
• (Rhizomes, tubers, spores, etc)
Algal Growth
Hydrodictyon (Net Algae)
Pithophora
Horse‐hair algae, very course, not slimy
COPPER RESISTANT
Spirogyra
Mostly found in the spring
Oscillatoria
Planktonic Algae
Cladophera
• Slimier than Pithophera, easier to control
Step #4
• Chemical Selection
• Two types of chemicals
– Systemic
• Pros‐ “preventative treatment”, multiple targets
• Cons‐ non‐target damage, costly, precise measurements, monitoring for target concentration, slow acting
• Ex. Flouridone and 2,4‐D
– Contact
• Pros‐ minimal non‐target damage (if applied appropriately), less costly, spot treatments
• Cons‐ will not kill root systems, will not prevent re‐growth
• Ex. Diquat and Endothal
Resources
• http://aquaplant.tamu.edu/index.htm
• http://www.mapms.org/plant_reference.pdf
• http://plants.ifas.ufl.edu/
How to Decide?
• Target plant
• Desired results
• Treatment Area
– Water volume, and size and shape of water body
• Irrigation and Water Use Restrictions
• Water Movement
Non‐Pesticide Applications
• Pond Dye
• Alum
• B&E
Step #5 Application
• READ THE LABEL
– Safety requirements
– Method of application
– Restrictions
– Storage and clean‐up
• Test the water before treatment
– DO
– Alkalinity
– pH
Fish Kills
• The vast majority of fish kills resulting from chemical applications are a results in a drop in DO, not chemical toxicity
– Decaying plant matter consumes oxygen
– Less material available to photosynthesis
• All copper compounds can be toxic to fish if used above labeled rates and can be toxic in soft or acidic waters even at label rates
How to prevent a drop in DO
• Apply early in AM
• If heavy growth, only treat ½ or 1/3 of water at a time
• Do not treat if water is less than 5mg/l DO
• Keep aeration on during the night
Monitoring
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Photo Document
Watch for non‐target damage
Listen to stake holders
Determine what is a “successful” treatment