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77 Cards in this Set

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What roles to plants play in a healthy aquatic ecosystem?
- Produce oxygen for other life forms in the lake
- Prevent shoreline erosion
- Stabilize the lake bottom
- Provide food, habitat for fish, waterfowl, and other aquatic animals
How can excessive plant growth adversely affect the ecology and use of a body of water?
- Curtail / prevent recreational use (swimming, boating, fishing)
- Impart taste or odor to drinking water
- Hamper water treatment
- Adversely affect aesthetics, resort trade, or property value
- Produce toxins
What is an emergent aquatic plant? How does it grow?
Rooted in shallow water, so that most of their growth extends above the water line. Esp. on wetlands, shorelines, and water saturated soil.
What is a submergent aquatic plant? How does it grow?
A plant that grows primarily under the water surface.
What is a floating-leaved aquatic plant? How does it grow?
These occur on the water surface. Free-floating ones have short roots not attached to the bottom, rooted ones have large floating leaves.
What is algae? How does it grow?
Primitive, simple plants without stems, leaves, or a vascular system.

Free floating float.
Filamentous grow on rocks, weeds, piers, etc. It can also break loose and float.
Rooted attach to the bottom (despite the name, they don't have roots).
What is the means of dispersal of emergent aquatic plants?
Underground root system
What is the means of dispersal of submergent aquatic plants?
Pondweeds: Vegetatively (roots, runners) or by seeds
Whorled leaf plants: being uprooted, then floating
Water celery: the book doesn't say :S
What is the means of dispersal of floating-leaved aquatic plants?
Free-floating: wind, causing accumulation on shorelines
Rooted: the book doesn't say :S
What is the means of dispersal of algae?
Free-floating: floating
Filamentous: breaking loose and floating away
Rooted: doesn't say :S
Give some examples of emergent aquatic plants.
Cattails, arrowhead, bulrushes, purple loosestrife
Give some examples of submergent aquatic plants.
Pondweeds: curlyleaf, sago
Whorled leaf plants: water milfoil
Water celery: tapegrass, eelgrass
Give some examples of floating-leaved aquatic plants.
Free-floating: lesser duckweed
Rooted: water lilies, spatterdock, American lotus, watershield
Give some examples of algae.
Free-floating: blue green
Rooted: Chara, Nitella
What are the problems emergent aquatic plants can cause?
Stopping recreational uses
What are the problems submergent aquatic plants can cause?
Motorboats cutting and spreading whorled leaf plants, restricting boating and fishing by how thick it is, reducing fish and waterfowl habitat
What are the problems floating-leaved aquatic plants can cause?
Doesn't really say.
Free-floating accumulate on shores and in emergent plants, often in thick layers that are difficult to control.
Rooted are beneficial.
What are the problems free-floating algae can cause?
When large amounts die, they rot, and the decay bacteria use up the oxygen in the water, causing fish kills. The dead algae may also release toxic chemicals into the water.
Which emergent aquatic plant is the most likely to be a pest (hint: it is an exotic)
Purple loosestrife
Which submergent aquatic plants are the most likely to be a pest (hint: exotics)
Curlyleaf pondweed, Eurasian water milfoil
Which algae are the most likely to be a pest
Blue green, a type of free-floating or planktonic
List the advantages of chemical control of aquatic plants.
- longer lasting control than mechanical methods
- less physical labor
- may cost less
- can only target pest species
List the disadvantages of chemical control of aquatic plants.
- restrictions on water use
- oxygen depletion from killing too many plants at once, leading to fish kills
- sudden release of nutrients from killing many plants at once can cause algae growth
- inherent risk to people and non targets associated with any pesticide use
What is the beneficial role of fish in WI?
- balance ecosystems by eating plants, insects, other fish, and being a food source
- people like to fish
- fish farms and hatcheries raise fish for food, feed, fertilizer, bait, and release into state waters
Why should we control fish? Hint: there are five situations.
1. Eliminating undesirable or competing fish from fish rearing.
2. Removing exotics or undesirables from a body of water.
3. Ruining stunted fish to bring a population into balance.
4. Eliminating fish from a hatchery water supply to prevent a reservoir of disease causing organisms.
5. Treating spawning sites to prevent overpopulation of an individual species.
Who gives approval for conducting chemical treatments for fish control?
WI Bureau of Fisheries Management
Why is post treatment management important in the long term success of chemical fish control?
Because populations can grow rapidly to refill the void left by the dead fish, often in three years time. Also, there may be unauthorized restocking of fish. Finally, the toxicant can move downstream and cause fish kills.
What are the two main reasons why mosquito control might be warranted?
Nuisance and disease
What are the structural features of mosquito eggs?
1/25 inch, light colored at first, but darkening within 24 hours, lateral extensions which allow floating or spines to trap air underneath and allow floating, or built as a raft to allowing floating
What are the structural features of mosquito larvae?
Mouthparts consist of a bristle to filter food, most have an air tube on the penultimate (8th) abdominal segment
What are the structural features of mosquito pupae or wigglers?
Only two body segments, trumpets (respiratory structures) on the thorax, and paddles on the abdomen
What do you need to know about a mosquito species before embarking on a control program?
- types and locations of breeding sites
- number of generations per year
- host preference
- seasonal population levels, and how rainfall effects populations
- flight range
- common resting areas
- if they serve as vectors
Describe the habits of Aedes triseriatus.
Tree-hole, attracted to lay eggs in any small containers. Eggs laid above the water line. Day feeders, do not disperse far from breeding areas.
Describe the habits of Aedes vexans.
Most common pest mosquito in WI. Floodwater, breeds roadside puddles, river bottoms, and the like. Eggs can remain dormant for five years. Migrate 15-20 miles, feed at dusk and after dark.
Describe the habits of Culex pipiens.
Breed in permanent or temporary pools of water that a high in organic material, including ditches, sewage lagoons. Eggs laid in rafts.
Name the three main mosquito borne diseases in Wisconsin and the vector for each.
La Crosse Encephalitis: Ae. triseriatus.
West Nile: C. pipiens.
Dog heartworm: Ae. vexans
What events are necessary for an herbicide to kill a plant?
- it must be absorbed into a plant.
- if necessary, it must be moved to the sensitive part of the plant
- it must block an important process in the plant
What is the use of contact herbicides?
Most effective on actively growing seedlings.
What is the limitation of contact herbicides?
Normally do not proved residual control.
What is the use of systemic herbicides?
Can kill plants even if all the leaves are not treated.
What actives are found in algicides?
Copper sulfate, copper chelate. Can also kill other plant life than algae.
What types of piscides are commonly used?
Botanicals, such as rotenone, and lampricides such as TFM and Bayluscide
List some precautions with adjuvants.
Over application can lead to injury of desirable plants, compatibility problems, reduced pest control.
What formulations are more likely to cause phytotoxicity?
Submergent plants, algae, and mosquito larvae are often best treated with what formulation?
G (also pellets and briquets)
When do you need a permit from the DNR to control aquatic pests?
When applying pesticides to Wisconsin waters. (I assume this means ALWAYS?)
What does the DNR consider before granting a permit for aquatic pest control?
- potential human and environmental hazards
- whether the proposed treatment will provide relief from the pest
- whether there will be unreasonable restrictions on existing water uses
These permits are for one treatment season only.
What are the certification requirements for someone applying pesticides to waters of the state?
Certification in 5.0 whenever...
- The applicator is for hire.
- The treated area is bigger than 1/4 acre.
- The product is restricted use.
- Liquid chemicals are going to be used.
After the DNR has granted a permit for application to waters, they can limit of stop your use. When will this happen?
- if it determines the treatment will be ineffective
- if it decides it will cause unreasonable restrictions on use of that water
- or it will produce unnecessary adverse side effects on non targets
What regulations are about the control of fish?
Permits are only issued for landlocked waters. Permit must be obtained from the DNR area fish manager. Application must be done under the supervision of a DNR employee.
Explain some details about a hydraulic sprayer.
Commonly used for herbicide application from boat and mosquito larvicide application from truck. Sometimes a direct-metering unit is used for treating large areas of water, which does not use a spray tank. (Are these like typical powersprayers? Unclear.)
A handgun is normally used for herbicide and piscicide applications, and its nozzle should provide a ____ flow rate, ____ stream, and _____ droplet size.
High flow rate, straight stream, large droplet size
What is used to apply herbicides just below the water surface?
Short hoses, spaced at approximately 2 foot intervals, on a short bow- or stern-mounted boom.
What is used to apply herbicides in deep water?
Nozzles located at the ends of long, weighted hoses that trail from a boom on the bow of the boat.
What is used to apply granular herbicides to water?
A bow-mounted centrifugal or blower-type spreader. Blowers create less dust than centrifugal.
When in a plant's life cycle is chemical control best performed?
Young, growing plants.
How do you prevent oxygen depletion when using aquatic herbicides?
By treating young plants (i.e. in spring and summer)
What can affect the performance of aquatic herbicides?
- water temperature at time of treatment (normally over 60 F required)
- amount of sunlight before and after treatment (must be enough to allow active growth, so they can uptake the herbicide)
Why is one herbicide application often not enough?
- most herbicides have limited residual
- they won't prevent seeds from sprouting or vegetative reproduction in perennials
- sometimes the treatment opens the way for different weeds to come in, which then must be treated
- different plants become pests at different times of year, and must have a treatment targeted for the right season
Describe rotenone's characteristics.
- restricted use
- comes in a powder and liquid formulation, but only the liquid is allowed in WI
- warmer water results in a faster fish kill
- fish will try to avoid the toxicant
- it is absorbed by aquatic plants and suspended solids, reducing effectiveness
- natural breakdown: 2-8 weeks in summer, 3-4 mo. in winter
- alkaline, turbid, well lit, high oxygen speed up breakdown
What are the factors to consider for determining the best time to treat for fish?
- lowest water levels usually are in midsummer or winter
- thorough dispersion of chemicals in easiest during turnover periods (what the heck does that mean?)
- many fish have predictable behavior during certain seasons or certain conditions (water level, temperature)
- low water temperature = longer toxicity
- dense vegetation can slow down a product's spread and can cause high pH which reduces period of toxicity (may require a higher concentration of product)
- thick ice can reduce the amount of water to be treated, but can hamper effective observation
- public use is less in the fall, dead fish may potentially be left in place
What limitations are there on a body of water after fish treatment?
- livestock should not drink the water
- should not be used for stock watering or crop irrigation
- no swimming
- don't eat the poisoned fish
How would you apply psicicide to a lake?
small to moderate lakes - from a boat using a boat bailer or a pump, although a weighted hose may be needed to treat deep water
- place live cages of fish at various points to make the product reached all levels
How would you apply psicicide to a stream?
- liquids are normally used in drip barrels (a 30 or 55 gal drum calibrated to discharge the product over 8 hours)
- take stream flows in cubic feet per second, learn the length of time it takes for water to move between drip stations (use a dye)
- drip stations should be 6 hours apart
- the end should be a drained pond
How would you apply psicicide to inaccessible areas?
With a backpack sprayer.
Explain detox techniques for pisicicides.
Potassium permanganate (KMnO4) or chlorine bleach will detox rotenone. Best done with a drip barrel. Dilute prior to application. Only need to detox in stream treatments and lake outlets.
When and where is adult mosquito control performed?
- recreational areas
- around known harborage areas
- residential areas when populations or disease potential is high
- to supplement larviciding by keeping adults from entering from neighboring areas
What is the timing and persistence of adulticide applications for mosquitoes?
aerosols - normally works for a very short period of time, normally must contact adults directly, so applied when they are seen
ULV - area-wide, normally when they are most active like dusk or dawn
- water-diluted sprays normally work for 10-14 days, applied during the day
When is mosquito larviciding important?
- where disease carrying mosquitoes are common
- when nuisance species are a yearly problem
What factors should be considered when choosing a mosquito larvicide?
- target pest, habitat
- size and type of area to be treated
- water quality
- other animals and pests present
- domestic uses, ecological functions of site
___% of the breeding is taking place in ____% of the water (mosquitoes)
95%, 10%
Inspect mosquito breeding sites every ___ days.
List the three factors you need to determine to calculate the amount of pesticide to apply to standing water.
1. The area or volume to be treated.
2. The dosage of pesticide required to control the pest.
3. The amount of formulated material required to give the proper dosage.
List the three factors you need to determine to calculate the amount of pesticide to apply from a moving boat.
1. Amount of spray solution delivered per unit time
2. The speed of the boat
3. The effective swath width
Describe how to calculate how much pesticide to use in flowing water.
1. Determine discharge rate of the water, that is, the CFS (cubic feet per second). width x depth x velocity x 0.9
2. Determine amount of pesticide in ml need for rate in ppm. ml / minute = discharge rate (CFS) x ppm desired x 1.7
ml of pesticide = ml of pesticide per minute x ECT (in min)
3. Determine the pumping rate of sprayer in gal per min.
4. Determine output of spray tank in ml of output. ml of output = ECT (effective contact time in min) x pumping rate (GPM) x 3,785
5. Determine amount of water to add to the spray tank. ml of water = total solution in sprayer (step 4) - amount of pesticide (step 2)
How many feet are in an acre?
43,560 square feet
(standing water application) lbs of product needed = ?
2.7 lbs x ppm desired x acre-ft