Aquatic Invasive Species
About
- What are Aquatic Invasive Species?
- Why are Aquatic Invasive Species a Problem?
- How Do They Become A Problem?
- Why Should We Care?
- If it is Pretty or Beneficial, It Can't Be a Problem, Right?
- I found a new aquatic invasive species not known to occur in my lake, wetland or stream, what do I do now?
- How Does DNR Control Aquatic Invasives?
- Introducing exotic species (from other regions or countries) who lack natural competitors and predators to keep them in check.
- Disrupting the delicate balance of native ecosystems by changing environmental conditions (e.g., stream sedimentation, ditching, building roads) or by restricting or eliminating natural processes (e.g., fire). In such instances, even some native plants and animals can become invasive.
- Spreading invasive species through various methods. Some examples:
- Moving watercrafts from waterbody to waterbody without removing invasive plants and animals or draining water
- Moving live fish from a waterbody
- Releasing live non-native animals and plants into the wild
- Carrying seeds of invasive plants on footwear or pet’s fur
- Introducing exotic species (from other regions or countries) who lack natural competitors and predators to keep them in check.
- Disrupting the delicate balance of native ecosystems by changing environmental conditions (e.g., stream sedimentation, ditching, building roads) or by restricting or eliminating natural processes (e.g., fire). In such instances, even some native plants and animals can become invasive.
- Spreading invasive species through various methods (e.g., moving watercrafts from waterbody to waterbody without removing invasive plants and animals, roadside mowing, and importing firewood).
What are Aquatic Invasive Species?
Aquatic Invasive species are plants, animals and pathogens that are "out of place." A species is regarded as invasive if it has been introduced by human action to a location, area, or region where it did not previously occur naturally (i.e., is not native), becomes capable of establishing a breeding population in the new location without further intervention by humans, and spreads widely throughout the new location.
Why are Aquatic Invasive Species a Problem?
Aquatic invasive species often leave their predators and competitors behind in their native ecosystems. Without these natural checks and balances they are able to reproduce rapidly and out-compete native species. Once established they can alter ecological relationships among native species and can affect ecosystem function, economic value of ecosystems, and human health.
How Do They Become A Problem?
Humans have created conditions where plants and animals can aggressively invade and dominate water bodies in three ways:
Why Should We Care?
Economics
In the United States, expenses associated with ecological damage and control of invasive species is estimated at $137 billion per year and increasing.1
In Wisconsin, some industries affected negatively by invasive species include sport and commercial fishing, forestry, and raw water users (power companies and utilities). These expenses are passed on to Wisconsin consumers (for example, in the form of higher water and electric bills)
The Great Lakes sport and commercial fishing industry, valued at almost $4.5 billion, is at risk due to the growing numbers of invasive species present in its waters. For example, invasive round gobies eat the eggs of sport fish such as small-mouth bass, trout and sturgeon in the nearshore areas of Lake Michigan.
Invasive shrubs such as buckthorn and honeysuckle prevent the regeneration of young trees, causing a long term but very serious impact on forestry in Wisconsin - a $20 billion dollar per year industry. Control of buckthorn alone has been estimated at $500-$2,000 per acre over multiple years.
In 2001, Wisconsin Electric Power Company reported that they were spending $1.2 million per year in the control of zebra mussels on their Lake Michigan power plants. These animals congregate on and clog intake and distribution pipes.
Health
Some invasive species may cause significant health problems. For example, a South American strain of human cholera-causing bacteria was found in ballast water tanks of ships in the port of Mobile, Alabama in 1991. Also, sharp zebra mussel shells can cut the feet of unsuspecting swimmers and waders.
Health risks aren't only confined to water-dwelling invasive species. Simply rubbing against wild parsnip with bare skin can cause burned and blistering arms and legs. This roadside and grassland invasive is spreading rapidly in Wisconsin, but few people know of its dangerous impacts.
Ecology
Humans have created conditions where plants and animals can aggressively invade and dominate natural areas and waterways in three ways:
The net result is a loss of diversity of our native plants and animals as invasive species rapidly multiply and take over. About 42% of the species on the federal Threatened or Endangered species lists are at risk primarily because of invasive species.
In our waterways, the rapid spread of zebra mussels shows how profoundly an invasive species can alter the environment. These tiny mussels - with huge appetites for microscopic plants and animals - rapidly reproduce and through their large numbers are capable of severely altering their environment by reducing the food supply for native organisms and by enhancing conditions for the rapid growth of blue-green algae and aquatic vegetation.
In our woodlands, garlic mustard can completely cover the ground with first- and second-year plants in a matter of years. This European garden herb not only steals most light and nutrient resources from our native wildflowers, it is also thought to secrete a chemical into the soil that inhibits growth of other plants.
Recreation
Hunters, hikers and birdwatchers are finding that they can no longer walk in their favorite natural areas. Thorny multiflora rose, dense stands of buckthorn and other invaders fill in the understory of our once open forests and grasslands. As the habitat is modified by such invasive plant species, the wildlife that depends on it disappears as well. Invasive animals such as the mute swan can also change our wildlife opportunities by chasing away all waterfowl from the waterbodies that they occupy.
Fishing outings can result in disappointment as aquatic invasive species modify our lake and stream habitat. Invasive animals such as the rusty crayfish gobble up aquatic plants like underwater lawn mowers, reducing habitat for native fish at every stage of their life cycle. They may even eat the eggs of our favorite sport fish. Eurasian water milfoil can clog boat motors, preventing free movement throughout Wisconsin waters.
This threatens a national sport and commercial fishing industry that supports 81,000 jobs in the Great Lakes region.
ReferencesIf it is Pretty or Beneficial, it Can't Be a Problem, Right?
This isn't true. For example, purple loosestrife- which is beautiful when it blooms- can cause ecological damage when it replaces other wetland plants that help the environment.
I found a new aquatic invasive species not known to occur in my lake, wetland or stream
Follow one of these links for the steps:
How does the DNR control aquatic invasives?
Watercraft Inspection
This effort involves dissemination of information to anglers and recreational boaters to make them aware of what invasive species look like and what precautions they should take to avoid spreading them. It also involves visual inspection of boats to make sure they are "clean" and demonstration to the public of how to take the proper steps to clean their boats, trailers, and boating equipment. Watercraft inspectors also install signs at boat landings informing boaters of infestation status, state law, and steps to prevent spreading invasives.
Monitoring
This effort involves monitoring for aquatic invasive species, including zebra mussels, Eurasian water milfoil, spiny waterfleas, and rusty crayfish. For zebra mussels, it involves collecting samples for veliger (larval zebra mussel) analyses and deployment of substrate samplers. There are also specific sampling procedures for spiny waterfleas and rusty crayfish.
Information and Education
In close cooperation with UW Extension and Wisconsin Sea Grant, education efforts focus on working with resource professionals and citizens statewide to teach boaters, anglers, and other water users the steps to take to prevent transporting aquatic invasives to new waters. Efforts also involve addressing other potential mechanisms of introduction, including aquarium pet release and water gardening. Many educational tools are used to reach the public - brochures and publications, watch cards and wild cards, public service announcements and displays at parks, sport shows, convention and symposiums.
Purple Loosestrife Biological Control
A citizen-based project that emphasizes using two safe, purple loosestrife foliage-feeding beetle species, in combination with traditional methods, for controlling this invasive plant. Citizens of all ages make up the backbone of this cooperative program by rearing and releasing these insects in their local wetlands - and learning about these precious places in the process.
Contact Brock Woods, UWEX/DNR Purple Loosestrife Bio-control Coordinator for more information: (608)221-6349 or Brock.Woods@ces.uwex.edu.
Clean Boats, Clean Waters Volunteer program
Sponsored by the DNR, UW Extension, and the Wisconsin Association of Lakes, this program offers training on how to organize a watercraft inspection program, how to inspect boats and equipment, and how to interact with the public. Volunteers are also encouraged to help monitor for aquatic invasives. Workshops are open to adults and youth; adult groups are encouraged to work with local youth partners. Contact Erin Henegar, Volunteer Coordinator for the Invasive Species Program (715) 346-4978 or ehenegar@uwsp.edu for more information.
What Can We Do About Them?
Controlling invasive species is difficult and costly, and eradicating them is often impossible. Whenever possible, preventing invasive species from arriving in the first place is the best option. DNR staff monitor the presence and spread of invasive species, work with partners to educate the public, and research control methods. But citizens also play a key role in the campaign against invasive species. Here’s what you can do to help us fight these invaders.
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