Displaying items by tag: Science camp
Greetings Environmental Educator!
I'm writing with great news for the environmental education community!
Representative Taylor (Monona) and Senator Larson (Milwaukee) have secured over 32 co-sponsors from both legislative houses for the Wisconsin Children's Outdoor Bill of Rights.
Next steps and how you can help:
On January 5th, Representatives Taylor and Larson will publicly announce the bill and ask for the joint assembly to schedule a vote. With a great show of support from the EE community, we can ensure this bill's success. Here's what you can do:
1. Sign on to support! - show your support of the Children's Outdoor Bill of Rights and keep up to date on the bill's progress.
2. Get out your art smocks - encourage children's groups to create artwork that expresses how and why spending time outdoors is of value.
3. Come to the January 5th press conference at the state capitol - registration details to be announced.
To find out more about this initiative, including the official language in the bill, if your legislator is a co-sponsor, or who fellow supporters are, visit the EEinWisconsin.org website.
Please pass along this exciting news to colleagues!
For questions or comments, please contact:
Betsy Parker
Wisconsin Association for Environmental Education - Networking & Advocacy Chair
(608) 209-2909This email address is being protected from spambots. You need JavaScript enabled to view it.
Jennifer Giegerich
Wisconsin League of Conservation Voters - Legislative Director
(608) 661-0845This email address is being protected from spambots. You need JavaScript enabled to view it.
permalink=”http://www.swiftnaturecamp.com/blog”>
Eurasian Water Milfoil
Eurasian milfoil first arrived in Wisconsin in the 1960's. During the 1980's, it began to move from southern Wisconsin to lakes and waterways in the northern half of the state. This migration took place mainly by boaters not removing fragments from their boats as they went from lake to lake. In Minong Wisconsin. the milfoil increase has happened over the last 10 years or so. Today, many lakes in the region are trying many ways to eliminate this nonnative invasive species.
Eurasian Water Milfoil (Myriophyllum spicatum)
DESCRIPTION:
|
DISTRIBUTION AND HABITAT:
Eurasian milfoil first arrived in Wisconsin in the 1960's. During the 1980's, it began to move from several counties in southern Wisconsin to lakes and waterways in the northern half of the state. As of 1993, Eurasian milfoil was common in 39 Wisconsin counties (54%) and at least 75 of its lakes, including shallow bays in Lakes Michigan and Superior and Mississippi River pools.
Eurasian water milfoil grows best in fertile, fine-textured, inorganic sediments. In less productive lakes, it is restricted to areas of nutrient-rich sediments. It has a history of becoming dominant in eutrophic, nutrient-rich lakes, although this pattern is not universal. It is an opportunistic species that prefers highly disturbed lake beds, lakes receiving nitrogen and phosphorous-laden runoff, and heavily used lakes. Optimal growth occurs in alkaline systems with a high concentration of dissolved inorganic carbon. High water temperatures promote multiple periods of flowering and fragmentation.
LIFE HISTORY AND EFFECTS OF INVASION:
Unlike many other plants, Eurasian water milfoil does not rely on seed for reproduction. Its seeds germinate poorly under natural conditions. It reproduces vegetatively by fragmentation, allowing it to disperse over long distances. The plant produces fragments after fruiting once or twice during the summer. These shoots may then be carried downstream by water currents or inadvertently picked up by boaters. Milfoil is readily dispersed by boats, motors, trailers, bilges, live wells, or bait buckets, and can stay alive for weeks if kept moist.
Once established in an aquatic community, milfoil reproduces from shoot fragments and stolons (runners that creep along the lake bed). As an opportunistic species, Eurasian water milfoil is adapted for rapid growth early in spring. Stolons, lower stems, and roots persist over winter and store the carbohydrates that help milfoil claim the water column early in spring, photosynthesize, divide, and form a dense leaf canopy that shades out native aquatic plants. Its ability to spread rapidly by fragmentation and effectively block out sunlight needed for native plant growth often results in monotypic stands. Monotypic stands of Eurasian milfoil provide only a single habitat, and threaten the integrity of aquatic communities in a number of ways; for example, dense stands disrupt predator-prey relationships by fencing out larger fish, and reducing the number of nutrient-rich native plants available for waterfowl.
Dense stands of Eurasian water milfoil also inhibit recreational uses like swimming, boating, and fishing. Some stands have been dense enough to obstruct industrial and power generation water intakes. The visual impact that greets the lake user on milfoil-dominated lakes is the flat yellow-green of matted vegetation, often prompting the perception that the lake is "infested" or "dead". Cycling of nutrients from sediments to the water column by Eurasian water milfoil may lead to deteriorating water quality and algae blooms of infested lakes.
CONTROLLING EURASIAN WATER MILFOIL:
Preventing a milfoil invasion involves various efforts. Public awareness of the necessity to remove weed fragments at boat landings, a commitment to protect native plant beds from speed boaters and indiscriminate plant control that disturbs these beds, and a watershed management program to keep nutrients from reaching lakes and stimulating milfoil colonies--all are necessary to prevent the spread of milfoil.
Monitoring and prevention are the most important steps for keeping Eurasian water milfoil under control. A sound precautionary measure is to check all equipment used in infested waters and remove all aquatic vegetation upon leaving the lake or river. All equipment, including boats, motors, trailers, and fishing/diving equipment, should be free of aquatic plants.
Lake managers and lakeshore owners should check for new colonies and control them before they spread. The plants can be hand pulled or raked. It is imperative that all fragments be removed from the water and the shore. Plant fragments can be used in upland areas as a garden mulch.
DNR permits are required for chemical treatments, bottom screening, buoy/barrier placement, and mechanized removal.
Mechanical Control:
Mechanical cutters and harvesters are a common method for controlling Eurasian water milfoil in Wisconsin. While harvesting may clear out beaches and boat landings by breaking up the milfoil canopy, the method is not selective, removing beneficial aquatic vegetation as well. These machines also create shoot fragments, which contributes to milfoil dispersal. Harvesting should be used only after colonies have become widespread, and harvesters should be used offshore where they have room to turn around. Hand cutters work best inshore, where they complement hand pulling and bottom screening. A diver-operated suction dredge can be used to vacuum up weeds, but the technique can destroy nearby native plants and temporarily raise water turbidity.
Hand pulling is the preferred control method for colonies of under 0.75 acres or fewer than 100 plants. The process can be highly effective at selectively removing Eurasian water milfoil if done carefully; special care must be taken to collect all roots and plant fragments during removal. Hand pulling is a time-consuming process.
Bottom screening can be used for small-scale and localized infestations on sites with little boat traffic, but will kill native vegetation as well. The bottom screens are anchored firmly against the lake bed to kill grown shoots and prevent new sprouts, but screens must be removed each fall to clean off sediment that encourages rooting. Buoys can mark identified colonies and warn boaters to stay away. Bottom screens may exacerbate a milfoil population once removed, because Eurasian water milfoil will readily re-colonize the bare sediment.
Whenever possible, milfoil control sites should become customized management zones. For example, milfoil removal by harvesting can be followed by planting native plants to stabilize sediments against wave action, build nurseries for fry, attract waterfowl, and compete against new milfoil invasions.
Chemical Control:
Herbicide treatments are commonly used to control Eurasian water milfoil. While no herbicide treatment is completely selective for milfoil, timing treatment early in the spring as soon as water warms helps limit unintentional harm to native plants. Herbicide treatments are most effective combined with vigilant post-treatment monitoring and non-chemical controls such as hand-pulling milfoil as it returns. When used carelessly, chemical treatments can be disruptive to aquatic ecosystems, not selective in the vegetation affected, and can cause more harm than good.
Biological Control:
Eurhychiopsis lecontei, an herbivorous weevil native to North America, has been found to feed on Eurasian water milfoil. Adult weevils feed on the stems and leaves, and females lay their eggs on the apical meristem (top-growing tip); larvae bore into stems and cause extensive damage to plant tissue before pupating and emerging from the stem. Three generations of weevils hatch each summer, with females laying up to two eggs per day. It is believed that these insects are causing substantial decline in some milfoil populations. Because this weevil prefers Eurasian water milfoil, other native aquatic plant species, including northern water milfoil, are not at risk from the weevil's introduction. Twelve Wisconsin lakes are currently part of a two-year DNR project studying the weevil's effectiveness in curbing Eurasian water milfoil populations. The fungus Mycoleptidiscus terrestris is also under extensive research.
Swift Nature Camp was pleased in the summer of 2011 to take on this project in part supported by the local lake association and theWisconsin Department of Natural Resources. “ This is REAL hands on Science” said Emily the Director at Swift in-charge of the little critters. Our goal was to start with a local population and create an even lager population to release back into the water. During the summer we had 10 tubs of 50 gallons each. These were home to our beginning brood of weevils. Every few weeks we fed them and hoped that they were reproducing franticly....
Please pardon the amazing delay in getting you your weevil project results. I have some preliminary results, and will send you a copy of the complete report to be filed with the DNR when that is finished (February).
I have attached the counts from the subsamples I collected from some of the tubs during our release day. The results were below what we expected to raise, with tubs producing only 40-200 weevils each, rather than 670 each, but please do not be disappointed. The temperature records Emily kept gave me a lot of good information to look at. Your temperatures in the tanks averaged 71F, which is cooler than what we planned on (77F), probably due to the shadiness of the site. What this tells me is that your weevils' development was probably happening much slower than what we expected. My observations of the samples also found that the stems were in poor condition, possibly also an effect of the shadiness of the site.
But, hey, in spite of those unexpected problems (and the problem of having to hunt and search for milfoil stems!) we still released 1248 weevils to the lake, and that's nothing to sneeze at! So thanks again for all your hard work and being part of this pilot study. We will continue to work out the kinks in this protocol to make it truly achievable to the lake groups who need it.
Thanks!
Amy Thorstenson
Executive Director/Regional AIS Coordinator
Weevil_counts_Minong_Rearing_Tubs_Aug2011
Hi Swift Nature Camp
I asked Amy how the other groups did in their weevil rearing project for 2011. None of the three groups had great success rates. You saw her report on ours, Holcombe got their tanks too hot and Amy thinks the weevils developed faster than they could feed them, so they starved. Goose Lake ended up not collected the right species of milfoil, again causing their weevils to starve. So I guess we all learned something.
Amy is exploring the possibility of applying for another DNR research grant to fund another program in 2012.
So that begs the question. Do you want to try and raise weevils again? This means having to collect (and bundle) more EWM in 2012. EWM that we are not even sure we will have. Plus with the potential drawdown occurring sometime this year (hopefully late fall) that may have a negative impact on the weevils. If the drawdown occurs in stages beginning in September or October we would likely be fine. Plus we are planning a smaller EWM treatment this year so should be able to find EWM more easily.
We have the equipment, but do we have the desire? I would again help to support it, but would want to include some money in the new grant application to do so. Most of the money added would go to my summer technician so the costs would be much less than if I charged all my time. He could then help collect EWM, even help bundle if necessary.
Please let me know your opinions as soon as possible. No need to mess with it in the grant stuff, if there is no desire to try it again. Personally, I think we should, but I am just one in a bunch that need to make that decision.
Dave Blumer | Lake Scientist
DAVE
AS YOU KNOW SWIFT NATURE CAMP IS ALWAYS WILLING TO HELP.
PLUS, IT IS A WONDERFUL LEARNING EXPERIENCE FOR OUR CAMPERS.
Jeff Lorenz
Simply because they are active only at night and difficult to observe and understand, bats rank among our planet’s most misunderstood and intensely persecuted mammals. Those that eat insects are primary predators of the vast numbers that fly at night, including ones that cost farmers and foresters billions of dollars in losses annually. As such bats decline, demands for dangerous pesticides grow, as does the cost of growing crops like rice, corn and cotton.
Fruit and nectar-eating bats are equally important in maintaining whole ecosystems of plant life. In fact, their seed dispersal and pollination services are crucial to the regeneration of rain forests which are the lungs and rain makers of our planet.
Many of the plants which depend on such bats are additionally of great economic value, their products ranging from timber and tequila to fruits, spices, nuts and even natural pesticides.
Scary media stories notwithstanding, bats are remarkably safe allies. Where I live, in Austin, Texas, 1.5 million bats live in crevices beneath a single downtown bridge. When they began moving in, public health officials warned that they were diseased and dangerous--potential attackers of humans. Yet, through Bat Conservation International, we educated people to simply not handle them, and 30 years later, not a single person has been attacked or contracted a disease. Fear has been replaced by love as these bats catch 15 metric tons of insects nightly and attract 12 million tourist dollars each summer.
It is now well demonstrated that people and bats can share even our cities at great mutual benefit. As we will show through varied Year of the Bat activities, bats are much more than essential. They’re incredibly fascinating, delightfully likeable masters of our night skies.
Statement by Dr. Merlin Tuttle
Honorary Ambassador
As we near Earth Day 2012 it is important that
we all realize that the planting of 1 tree can make a difference.
Read more about How trees change our life
The information provided is in reference to urban forests, but these benefits and values also apply to rural forests.
Canopy, or tree canopy, is a term used to describe the leaves and branches of a tree or group of trees. In an urban forest, tree canopy is important to the potential benefits the forest may provide. In general, the more area it covers and the denser the canopy, the more benefits the trees can provide. Although one tree is better than none, 100 are better still. Whether the benefits are from one tree or many trees, they are all still real and most can be quantified in some way. Often, forest benefits are divided into three categories: social, economic, and ecologic. It is difficult to divide the benefits that the urban forest canopy provides into these categories because so many benefits fall into more than one.
Social Benefits
Just as with a rural forest, an urban forest provides many benefits. Numerous studies have been done about the social
and psychological benefits of “green” in urban environments. The findings of the studies make a strong case for the
importance of urban forests. Urban public housing residents who lived in buildings without trees and grass nearby were
asked about how they cope with major life issues. They reported more procrastination and assessed their issues as more
severe than residents with green nearby.
A study done with children with Attention Deficit Disorder (ADD) found that children with ADD were better able to focus
and concentrate after playing in natural, green settings, than in settings where concrete was predominant.
Apartment buildings with high levels of greenery have been shown to have approximately half the number of crimes
than those with little or no greenery. The results proved true for both property crimes and violent crimes. A similar study
found that residents living in areas without nearby nature reported more aggression and violence than those living with
nearby green. In addition to these specific studies, access to nature also provides humans with other social benefits.
Parks and other green spaces provide a space for people to play, walk, jog, birdwatch, or just sit quietly. These activities
are good for our physical health in a society that is increasingly sedentary. It is also good for our mental health by
providing a place to unwind. Trees also reduce noise levels.
Economic Benefits
The economic benefits of urban forests are increasingly being documented. Economics often becomes the language
used when it comes to urban forest management. Budgets of municipalities must cover an array of services, and the
benefits of an urban ecosystem must often be proven to secure funding. In a study that considered the costs and
benefits of municipal forests in five U.S. cities, the researchers found that for every dollar spent on trees, the benefits
returned were worth from $1.37 to $3.09. A little math tells us this is clearly a good investment.
Trees save money through reduced energy costs. Cities create what is referred to as a heat island. The concrete, asphalt,
buildings, and other surfaces absorb and hold heat from the sun. During hot summer days, cities can be five to nine
degrees warmer than surrounding areas. Shading, evapotranspiration, and wind speed reduction provided by trees help
conserve energy in buildings. A study conducted in Minneapolis, Minnesota, showed that trees placed in the proper
location can reduce total heating and cooling costs by eight percent.
Homeowners not only reduce costs of heating and cooling their homes, but increase the value of their property by
planting trees. Research suggests that property value can increase three to seven percent when trees are present. Trees
also make homes and neighborhoods more desirable places to live. One economic benefit that urban trees can provide,
but often don’t, is one based on products. Municipalities and tree services across the country have come up with ways
to use the wood that is cut from an urban forest. Products range from specialty furniture, to musical instruments, to
lumber for park shelters, to artwork. The income from selling products from the wood of trees being removed could be used to defray the cost associated with the removal, making trees an even better investment.
Trees and Climate Change
The information about how trees impact climate change is taken from the National Arbor Day website
http://www.arborday.org/globalwarming/treesHelp.cfm, and the American Forest Foundation website
www.americanforests.org/resources/climatechange/
Deciduous trees, planted on the west, east and south sides, will keep your house cool in the summer and let the sun
warm your home in the winter, reducing energy use.
Just three trees, properly placed around a house, can save up to 30% of energy use.
Trees or shrubs planted to shade air conditioners help cool a building more efficiently, using less electricity. A unit
operating in the shade uses as much as 10% less electricity than the same one operating in the sun.
Neighborhoods with well-shaded streets can be up to 6–10° F cooler than neighborhoods without street trees, reducing
the heat-island effect, and reducing energy needs.
Shaded parking lots keep automobiles cooler, reducing emissions from fuel tanks and engines, and helping reduce the
heat-island effect in communities.
Trees absorb carbon dioxide (CO2), the primary gas causing global climate change. Trees retain the carbon (C) from the
CO2 molecule and release oxygen (O2) into the atmosphere. The retained carbon makes up half the dry weight of a tree.
Forests are the world's second largest carbon reservoirs (oceans are the largest). Unlike oceans, however, we can grow
new forests. One acre of forestland will sequester between 150 - 200 tons of CO2 in its first 40 years.
permalink=”http://www.swiftnaturecamp.com/blog”>
Unlike other environment-related programs impacting schools, the Green Ribbon award will acknowledge high levels of achievement under three areas, rather than one:
1) environmental impact and energy efficiency;
2) healthy environment; and
3) environmental literacy.
Congressman Sarbanes, sponsor of the No Child Left Inside Act, praised the new program. "Robust environmental education will prepare students to be 21st Century innovators – developing technologies that are crucial to the future health of the environment and the American economy," Sarbanes added. “I am thrilled that the Department of Education has brought this new focus to environmental education.” To read the Congressman’s full press release, click here.
Don Baugh, Executive Director of the No Child Left Inside Coalition also lauded the program as a step in the right direction. “Recognizing schools for their environmental education achievements is an important part of the effort to advance the environmental literacy of our youth,” said Baugh. “Equally important is ensuring that the Elementary and Secondary Education Act provides support for schools to provide the high quality environmental education needed to prepare our students for college and the jobs of the future. We commend Secretary Duncan and Congressman Sarbanes for their leadership on this critical issue.”
With 2011 almost over did you know that it was the year of the Turtle?
If you did...What have you done about it.
If not there is still time to save nearly 40% of the turtles that are threatened .
permalink=”http://www.swiftnaturecamp.com/blog”>
Why Turtles, and Why Now?
Throughout the year, we will be raising awareness of the issues surrounding turtles through press releases, newsletters, photo contests, and related events. We believe that citizens, natural resource managers, scientists, and the pet and food and related industries can work together to address issues and to help ensure long-term survival of turtle species and populations.
Threats to US Turtles
- habitat loss and degradation
- overharvest of wild turtles for food, traditional medicines, and pets
- mortality from roads, agricultural machinery, fishing bycatch, and predators
- invasive exotic species and diseases
- loss of unique genetic makeup due to hybridization
- climate change
This email address is being protected from spambots. You need JavaScript enabled to view it. for our monthly newsletters, containing:
- A downloadable turtle photo calendar for each month, including a photo contest – your photo could be in the calendar!
- Information about turtle conservation efforts and groups, and how you can help
- Interviews with turtle experts, and answers to selected questions that YOU send us!
- Information on how you can help spread the word about turtles
- Educational materials
- Turtle art, poetry, and cultural information
- ... and much, MUCH, more!
- At Swift Nature Camp you can learn more with hands on studies with turtles.
Greetings Environmental Educator!
I'm writing with great news for the environmental education community!
Representative Taylor (Monona) and Senator Larson (Milwaukee) have secured over 32 co-sponsors from both legislative houses for the Wisconsin Children's Outdoor Bill of Rights.
Next steps and how you can help:
On January 5th, Representatives Taylor and Larson will publicly announce the bill and ask for the joint assembly to schedule a vote. With a great show of support from the EE community, we can ensure this bill's success. Here's what you can do:
1. Sign on to support! - show your support of the Children's Outdoor Bill of Rights and keep up to date on the bill's progress.
2. Get out your art smocks - encourage children's groups to create artwork that expresses how and why spending time outdoors is of value.
3. Come to the January 5th press conference at the state capitol - registration details to be announced.
To find out more about this initiative, including the official language in the bill, if your legislator is a co-sponsor, or who fellow supporters are, visit the EEinWisconsin.org website.
Please pass along this exciting news to colleagues!
For questions or comments, please contact:
Betsy Parker
Wisconsin Association for Environmental Education - Networking & Advocacy Chair
(608) 209-2909This email address is being protected from spambots. You need JavaScript enabled to view it.
Jennifer Giegerich
Wisconsin League of Conservation Voters - Legislative Director
(608) 661-0845This email address is being protected from spambots. You need JavaScript enabled to view it.
permalink=”http://www.swiftnaturecamp.com/blog”>
Eurasian Water Milfoil
Eurasian Water Milfoil (Myriophyllum spicatum)
DESCRIPTION:
|
DISTRIBUTION AND HABITAT:
Eurasian milfoil first arrived in Wisconsin in the 1960's. During the 1980's, it began to move from several counties in southern Wisconsin to lakes and waterways in the northern half of the state. As of 1993, Eurasian milfoil was common in 39 Wisconsin counties (54%) and at least 75 of its lakes, including shallow bays in Lakes Michigan and Superior and Mississippi River pools.
Eurasian water milfoil grows best in fertile, fine-textured, inorganic sediments. In less productive lakes, it is restricted to areas of nutrient-rich sediments. It has a history of becoming dominant in eutrophic, nutrient-rich lakes, although this pattern is not universal. It is an opportunistic species that prefers highly disturbed lake beds, lakes receiving nitrogen and phosphorous-laden runoff, and heavily used lakes. Optimal growth occurs in alkaline systems with a high concentration of dissolved inorganic carbon. High water temperatures promote multiple periods of flowering and fragmentation.
LIFE HISTORY AND EFFECTS OF INVASION:
Unlike many other plants, Eurasian water milfoil does not rely on seed for reproduction. Its seeds germinate poorly under natural conditions. It reproduces vegetatively by fragmentation, allowing it to disperse over long distances. The plant produces fragments after fruiting once or twice during the summer. These shoots may then be carried downstream by water currents or inadvertently picked up by boaters. Milfoil is readily dispersed by boats, motors, trailers, bilges, live wells, or bait buckets, and can stay alive for weeks if kept moist.
Once established in an aquatic community, milfoil reproduces from shoot fragments and stolons (runners that creep along the lake bed). As an opportunistic species, Eurasian water milfoil is adapted for rapid growth early in spring. Stolons, lower stems, and roots persist over winter and store the carbohydrates that help milfoil claim the water column early in spring, photosynthesize, divide, and form a dense leaf canopy that shades out native aquatic plants. Its ability to spread rapidly by fragmentation and effectively block out sunlight needed for native plant growth often results in monotypic stands. Monotypic stands of Eurasian milfoil provide only a single habitat, and threaten the integrity of aquatic communities in a number of ways; for example, dense stands disrupt predator-prey relationships by fencing out larger fish, and reducing the number of nutrient-rich native plants available for waterfowl.
Dense stands of Eurasian water milfoil also inhibit recreational uses like swimming, boating, and fishing. Some stands have been dense enough to obstruct industrial and power generation water intakes. The visual impact that greets the lake user on milfoil-dominated lakes is the flat yellow-green of matted vegetation, often prompting the perception that the lake is "infested" or "dead". Cycling of nutrients from sediments to the water column by Eurasian water milfoil may lead to deteriorating water quality and algae blooms of infested lakes.
CONTROLLING EURASIAN WATER MILFOIL:
Preventing a milfoil invasion involves various efforts. Public awareness of the necessity to remove weed fragments at boat landings, a commitment to protect native plant beds from speed boaters and indiscriminate plant control that disturbs these beds, and a watershed management program to keep nutrients from reaching lakes and stimulating milfoil colonies--all are necessary to prevent the spread of milfoil.
Monitoring and prevention are the most important steps for keeping Eurasian water milfoil under control. A sound precautionary measure is to check all equipment used in infested waters and remove all aquatic vegetation upon leaving the lake or river. All equipment, including boats, motors, trailers, and fishing/diving equipment, should be free of aquatic plants.
Lake managers and lakeshore owners should check for new colonies and control them before they spread. The plants can be hand pulled or raked. It is imperative that all fragments be removed from the water and the shore. Plant fragments can be used in upland areas as a garden mulch.
DNR permits are required for chemical treatments, bottom screening, buoy/barrier placement, and mechanized removal.
Mechanical Control:
Mechanical cutters and harvesters are a common method for controlling Eurasian water milfoil in Wisconsin. While harvesting may clear out beaches and boat landings by breaking up the milfoil canopy, the method is not selective, removing beneficial aquatic vegetation as well. These machines also create shoot fragments, which contributes to milfoil dispersal. Harvesting should be used only after colonies have become widespread, and harvesters should be used offshore where they have room to turn around. Hand cutters work best inshore, where they complement hand pulling and bottom screening. A diver-operated suction dredge can be used to vacuum up weeds, but the technique can destroy nearby native plants and temporarily raise water turbidity.
Hand pulling is the preferred control method for colonies of under 0.75 acres or fewer than 100 plants. The process can be highly effective at selectively removing Eurasian water milfoil if done carefully; special care must be taken to collect all roots and plant fragments during removal. Hand pulling is a time-consuming process.
Bottom screening can be used for small-scale and localized infestations on sites with little boat traffic, but will kill native vegetation as well. The bottom screens are anchored firmly against the lake bed to kill grown shoots and prevent new sprouts, but screens must be removed each fall to clean off sediment that encourages rooting. Buoys can mark identified colonies and warn boaters to stay away. Bottom screens may exacerbate a milfoil population once removed, because Eurasian water milfoil will readily re-colonize the bare sediment.
Whenever possible, milfoil control sites should become customized management zones. For example, milfoil removal by harvesting can be followed by planting native plants to stabilize sediments against wave action, build nurseries for fry, attract waterfowl, and compete against new milfoil invasions.
Chemical Control:
Herbicide treatments are commonly used to control Eurasian water milfoil. While no herbicide treatment is completely selective for milfoil, timing treatment early in the spring as soon as water warms helps limit unintentional harm to native plants. Herbicide treatments are most effective combined with vigilant post-treatment monitoring and non-chemical controls such as hand-pulling milfoil as it returns. When used carelessly, chemical treatments can be disruptive to aquatic ecosystems, not selective in the vegetation affected, and can cause more harm than good.
Biological Control:
Eurhychiopsis lecontei, an herbivorous weevil native to North America, has been found to feed on Eurasian water milfoil. Adult weevils feed on the stems and leaves, and females lay their eggs on the apical meristem (top-growing tip); larvae bore into stems and cause extensive damage to plant tissue before pupating and emerging from the stem. Three generations of weevils hatch each summer, with females laying up to two eggs per day. It is believed that these insects are causing substantial decline in some milfoil populations. Because this weevil prefers Eurasian water milfoil, other native aquatic plant species, including northern water milfoil, are not at risk from the weevil's introduction. Twelve Wisconsin lakes are currently part of a two-year DNR project studying the weevil's effectiveness in curbing Eurasian water milfoil populations. The fungus Mycoleptidiscus terrestris is also under extensive research.
Simply because they are active only at night and difficult to observe and understand, bats rank among our planet’s most misunderstood and intensely persecuted mammals. Those that eat insects are primary predators of the vast numbers that fly at night, including ones that cost farmers and foresters billions of dollars in losses annually. As such bats decline, demands for dangerous pesticides grow, as does the cost of growing crops like rice, corn and cotton.
Fruit and nectar-eating bats are equally important in maintaining whole ecosystems of plant life. In fact, their seed dispersal and pollination services are crucial to the regeneration of rain forests which are the lungs and rain makers of our planet.
Many of the plants which depend on such bats are additionally of great economic value, their products ranging from timber and tequila to fruits, spices, nuts and even natural pesticides.
Scary media stories notwithstanding, bats are remarkably safe allies. Where I live, in Austin, Texas, 1.5 million bats live in crevices beneath a single downtown bridge. When they began moving in, public health officials warned that they were diseased and dangerous--potential attackers of humans. Yet, through Bat Conservation International, we educated people to simply not handle them, and 30 years later, not a single person has been attacked or contracted a disease. Fear has been replaced by love as these bats catch 15 metric tons of insects nightly and attract 12 million tourist dollars each summer.
It is now well demonstrated that people and bats can share even our cities at great mutual benefit. As we will show through varied Year of the Bat activities, bats are much more than essential. They’re incredibly fascinating, delightfully likeable masters of our night skies.
Statement by Dr. Merlin Tuttle
Honorary Ambassador