WI Lakes.net 2026 AIS Briefing

Aquatic invasive species (AIS) continue to pose some of the most significant ecological and economic threats to inland lakes across the Upper Midwest. With their ability to outcompete native species, disrupt food webs, damage habitat, and impair recreation, staying informed is essential for lake associations, anglers, paddlers, and waterfront property owners.

This 2026 update highlights key AIS concerns for Wisconsin—our primary focus—and provides a look at emerging and ongoing threats in Minnesota, Michigan, and Illinois. The annual cost to combat AIS in WI is expected to push beyond $13M given past costs. This reflects cost to combat and not necessarily the true ecological impact (displaced species, lost opportunity, disrupted cycles, etc).

This figure reflects statewide investments that include:

  • Monitoring and early detection
  • Watercraft inspection and decontamination
  • Local lake grants and rapid response funding
  • Enforcement of AIS transport laws
  • Outreach and education programs

AIS in Wisconsin: Current Species of Concern

Wisconsin’s Department of Natural Resources continues active AIS monitoring across the state’s waterbodies. Citizen monitors and partners play a central role in discovering new infestations and tracking established species. Many of these species fall under Wisconsin’s NR 40 invasive species rule, which classifies harmful plants, animals, algae, and pathogens. [dnr.wisconsin.gov]

Most Prevalent Aquatic Invasive Plants in Wisconsin

The following AIS plants remain widespread concerns, frequently appearing in verified waterbody lists across the state: [apps.dnr.wi.gov]

  • Eurasian Watermilfoil (Myriophyllum spicatum)
    Forms dense mats, inhibits boating, and crowds out native plants.
  • Curly-Leaf Pondweed (Potamogeton crispus)
    Early-season growth shades natives; sharp die-offs degrade water quality.
  • Purple Loosestrife (Lythrum salicaria)
    A wetland invader that displaces native vegetation and reduces habitat value.
  • Brittle Waternymph (Najas minor)
    A fast-spreading submerged annual found in many southern and central Wisconsin lakes.
  • Starry Stonewort (Nitellopsis obtusa)
    An invasive alga forming dense, star-shaped bulbils; increasingly detected in Wisconsin. [storage.go…leapis.com]

    High‑Risk or Restricted AIS Plants Under NR 40

    The state identifies additional prohibited or restricted species that require rapid response if detected:
    Hydrilla, Brazilian Waterweed, European Frog-bit, Parrot Feather, Yellow Floating Heart, Water Chestnut, and others. [storage.go…leapis.com]

    Aquatic Invasive Animals of Concern in Wisconsin

    Key faunal invaders documented across Wisconsin waterbodies include: [apps.dnr.wi.gov]

    • Zebra Mussels (Dreissena polymorpha) – Sharp-shelled filter feeders that alter water clarity and ecological balance.
    • Chinese & Banded Mystery Snails – Compete with native snails and degrade beach quality.
    • Rusty Crayfish (Faxonius rusticus) – Aggressively displaces native crayfish; destroys aquatic plant beds.
    • Invasive fish concerns, including introductions of Round Goby and Carp species, remain regionally relevant.

    How Wisconsin Manages AIS

    Wisconsin’s AIS strategy includes rapid detection, NR 40 enforcement, educational outreach, and lake-by-lake management permits for plant control. Citizens can report sightings via the DNR’s online reporting tool.

    Minnesota: Rising AIS Challenges and Notable Trends

    Minnesota remains a national hotspot for AIS research and early detection thanks to the Minnesota Aquatic Invasive Species Research Center (MAISRC) and the Minnesota DNR.

    Key Minnesota AIS Issues

    • Zebra Mussels: Widespread; recent studies link their presence to elevated mercury levels in fish, raising human health concerns. [lakeindependence.org]
    • Prohibited Invasive Species Expansion: Minnesota DNR recently classified 13 high‑risk AIS as prohibited to prevent introduction and spread. [invasivesp…esinfo.gov]
    • Invasive Carp Management: The state continues aggressive prevention efforts to keep carp species from expanding into northern lakes and rivers.

    Minnesota Monitoring and Data

    Minnesota maintains a continually updated AIS database covering occurrences of invasive plants, fish, invertebrates, and diseases. [mnatlas.org]


    Michigan: Watch Lists, Plant Threats, and Early Detection Priorities

    Michigan’s program emphasizes early detection and rapid response, supported by extensive watch lists and detection campaigns.

    Michigan Watch List Aquatic Invasive Species

    Michigan has designated 18 aquatic invasive species as high-risk, including:

    • 10 aquatic plants
    • 5 fish species
    • 2 crayfish species
    • New Zealand Mudsnail
      Efforts include public reporting via MISIN and statewide BioBlitz events. [michiganfarmnews.com]

    Notable Aquatic Plant Threats in Michigan

    Michigan’s watch list and field guides highlight plants with limited distribution but high invasion potential, including:
    Brazilian Elodea, European Frog-bit, Hydrilla, Water Chestnut, Yellow Floating Heart, Parrot Feather, and others. [lssu.edu]

    Statewide Program Focus

    Michigan’s inter-agency Invasive Species Program addresses species that threaten local ecosystems, focusing on early detection and rapid response to prevent establishment. [michigan.gov]


    Illinois: Key AIS Concerns in the Great Lakes and Statewide

    Illinois is a critical geographic link between the Mississippi River system and the Great Lakes, making it a priority region for invasive carp prevention and aquatic species management.

    Major Aquatic Invasives in Illinois

    Illinois Extension highlights several unregulated yet concerning AIS, including:
    Flowering Rush, Hydrilla, Brazilian Egeria, Purple Loosestrife, Eurasian Watermilfoil, Curly-Leaf Pondweed, Spiny Water Flea, Zebra Mussel, Asian Carp, Round Goby, Chestnut Lamprey. [extension….linois.edu]

    Invasive Carp Threat in Illinois River System

    The state remains a frontline defender against invasive carp entering the Great Lakes.
    A 2025 field study highlights ongoing monitoring of exploding Silver Carp populations and measures to prevent movement toward Lake Michigan. [chicago.suntimes.com]

    Statewide Coordination

    Illinois’ Wildlife Action Plan includes a comprehensive Invasive Species Campaign focusing on prevention, early detection, and interagency collaboration. [dnr.illinois.gov]


    Why AIS Management Matters for Wisconsin Lakes

    Wisconsin’s lake health—water clarity, habitat structure, fishing quality, and recreational value—depends on persistent vigilance. Neighboring states face similar threats, and regional collaboration has never been more important.

    How You Can Help

    • Inspect boats and gear: Follow Wisconsin’s “No Transport” law to remove all plants, animals, and mud.
    • Report sightings immediately: Wisconsin DNR’s reporting portal enables quick verification.
    • Volunteer for monitoring: Local lake associations and Water Action Volunteers welcome community scientists.
    • Stay informed: Many AIS now spread through gear, aquarium releases, and hitchhiking in bait and plant fragments.

    Conclusion

    Aquatic invasive species remain a dynamic challenge across the Upper Midwest, with Wisconsin at the center of coordinated regional efforts. By understanding which species pose the greatest risk—and by learning from neighboring states’ battles—we can better protect the lakes we love.

    If you’d like, I can turn this into a formatted PDF, add images, or adapt it for social media or newsletter distribution.

    Climate Change and Your Lake

    The change appears to be slow. In fact, it may not even appear to be noticeable. What are even the signs? Wisconsin and the Midwest are home to a wide variety of lakes, all of which may be impacted in different ways. In addition, management of lake issues has been an evolving practice since its inception, so adding contingency to a wrinkle for an imperfect science only makes things more complicated for stakeholders with controlled budgets. Wisconsinlakes.net has not yet seen a good guide or resource page that provides any real guidance surrounding the issue of climate change, most likely because to the naked eye it may appear to be normal issues continuing to manifest themselves, albeit in an accelerated or different manner. We hope the information within this posting proves beneficial to some. None of this is backed by research or academic sourcing. It is observational and is not universally applicable.

    To continue this in this post discussion, it must be understood that climate change is a real thing, not a made up concept from 1987. Most have accepted this by now. In fact climate change is being referred to as “climate shift” by many in the sense that climate is not simply changing but, but causing a physical shift of range of changes. Regardless of how you wish to catalog these changes internally, they are in fact a real thing and will likely require solutions based on adaptability and proactive maintenance rather than a fixed endgame solution.

    While coarse policy begins to take shape both nationally and globally, communities are faced with real world issues that impact people at the local scale, both economically and from a health and safety perspective. There are endless miles of utility infrastructure beneath the grounds surface, all of which are at some degree of risk. There are no fast and ready rules to apply because each of these communities geographical space is unique. Some face coastal concerns, some flooding, and yet some seismic. The geographical space and unique weather patterns all require custom approaches. Even more so with lakes. Lake types can differ greatly simply by being a few miles apart and will therefore act differently due to precipitation, landscape positions, watershed size, urban influence, temperature flux, and other factors both known and unknown.

    The term resiliency is often used to describe the process of making something able to withstand or adapt to change. There is also a general school of thought that believes that natural systems are generally more resilient than manufactured systems. Often potentially overlooked in this equation is general systems maintenance. Do systems lack resilience or do they generally lack maintenance? These can be difficult questions to answer. Even more importantly is the need to consider the tracking of assets for those same maintenance reasons.

    So how does all of this factor into a discussion about our lakes, climate change, and the quest for resiliency? Below is a list of potential considerations for your lake that can be potentially influenced by climate change:

    Shorelines: Several of the topics below have a degree of interplay, that is they do not operate independent of each other but each may influence each other. Shorelines can be impacted by water level and system volume, among other things. Vegetative systems that make up shorelines adapt to water levels but take decades to adjust since ecological systems react over time. Waves and ice add a dynamic, but these are still natural occurrences, whereas wakes are not.

    As climate reduces months of ice cover in Wisconsin, that is traded for more precipitation as rainfall. Additional months of rainfall throughout the Midwest can result in higher groundwater levels or longer periods of drawdown at dams and outlet structures. Elongated periods of high water put natural systems at risk as they can be exposed to extended periods of inundation, wave impact and even record high wake impacts. Several river systems in WI and throughout the midwest have shown signs of higher than average baseflow. Higher baseflow results in necessary shoreline adjustment, albeit incremental over time.

    Water elevation will be discussed further below, but sustained high water exposes shoreline not traditionally adapted to water inundation. Saturated soils may leach fines (smaller soil particles) and girdle vegetation roots, increasing the mortality of plants and increasing erosion or lateral loss of land.

    Reinforced shorelines are not absolute solutions. Man-made systems can be compromised by repeated overtopping, toe scour, or improper design. Research also suggests that hard armor shoreline reflects wave activity along adjacent unprotected shorelines and can have ecological impacts. These effects can have cumulative effects in urbanizing lake environment. Shoreline solutions will need to flexible rather than simplistic. Good solutions typically suggest bio-engineered shores capable of withstanding wave and wake punishment, but also regrowth of vegetation when possible.

    Sediment: 10/7/2023

    Water Level: TBA

    System Volume: TBA

    Infrastructure: TBA

    Lake Ecosystem: TBA

    Nutrients: TBA

    Our Second Love, Our Lakes

    On this Labor Day I hope most are getting the opportunity to get out onto their lakes to enjoy a wonderful day in the upper midwest. As the boating season begins to wind down and the leaves begin their annual color change we can reflect back and the summer that to many may seem like it never was. The Great Outdoors to many others has proven to be an excellent distraction to a world in apparent disarray. For some of us who have spent more time than usual out on the water it may have provided greater insight into the value of our surface waters; this includes public waters of the state, rivers for example for kayaking/canoeing, etc.

    What have we seen? Have we accumulated any new knowledge that has helped us become better stewards of the waters? Have we observed something new that has led us back to our home office to investigate the question on the internet? Have we shared information or questions with others? If our waters our something we truly cherish it takes more than a passive interest to preserve it.

    The diversity of lake users is greater today than it has ever been. This includes users of varying backgrounds with variable agendas. These agendas may not always be be in unison with the best interests to the waters we inhabit, but we can all hope to play in this sandbox in harmony. If our waters spoil well then the party is over. Our water resources do not have a hospital they can got to when they feel sick or are becoming undone. We are sickness but also the cure.

    This is a good time to sit back, enjoy the weather and reflect back on the things we can do better on with our lakes. What have turned a blind eye to for too long. Fall brings time to contemplate these things and plan for the winter and upcoming year. Start taking stock in the little things and track lake progress.

    Up Next, we’ll take a look at the process of video recording your shoreline.

    July – Lakes Appreciation Month

    As the title of this blog-article suggests, July is Lakes Appreciation Month! It’s in the dead of summer when most lake activities are fully ramped up. With the ongoing Pandemic 2020 the great outdoors have been a welcome distraction to some in their social distancing efforts. We fish and recreate on them, some of us even work on them.  Lakes are even drinking water sources for some of us, but do we really show and advocate our appreciation for them? It’s hard to say.  How is it that we even show appreciation for our lakes?  Consider some of the thoughts below:

    • By way of reading this article it is highly likely that you have already joined your local lake association, but have you ever looked beyond those borders? Perhaps there is a local watershed association as well.  Our lakes and streams tend to reflect what is draining to them and at times lake associations can get tunnel vision, over-focusing on in-lake issues. Watershed issues can be just as vital. Involvement with both lake and watershed management creates the holistic picture.
    • One silver lining of the pandemic and shelter in place order has been the spike in available online webinars at little to no cost.  I’ve attended webinars as far away as the Maine Lakes Society, and while much of the material looks familiar at first glance, there is always something that can be picked up.  Watch the Twitter Feed for occasional announcements.
    • Check out your local volunteer lake monitoring opportunities. There is much to be learned by sitting and listening to others but getting your hands on the equipment and learning the components of the number and how the information is collected can give you new insight and understanding.

    So, July is a big month; continue practicing social distancing from others, but that should be easy enough to do from your lake’s perspective, boating, kayaking, canoeing, shore fishing, etc.  Consider how you can show you appreciation for your lakes and it will continue to give back to you.

    Welcome to Wisconsin Lakes.net

    Happy Independence Day! Welcome to this website-Blog!

    I’ve always loved the idea of “home”. Wisconsin is where I grew up and I am happy to be back home working on our lakes and watercourses. I have worked at offices located in several other states along the way, with the opportunity to work on projects in adjacent states. It has been a great adventure with a tremendous amount of experience to be gained in a variety of environments and among some extremely talented minds, but I always knew this was a domain I desired to re-inhabit.

    I guess I should caveat things by saying that I didn’t just appear overnight, I have been working on projects, primarily in southern part of the state for the last 10 years, but mostly from a distance, slowly integrating into the local policies and protocols. Make no bones about it, Wisconsin is different and operates differently than many other states. This isn’t exactly a bad thing, but integral in understanding the flow of things when you are at the plate.

    Wisconsin is such a very water and natural resources rich state that it can become part of your very being. It can become imprinted on you at a young age and continues to follow you wherever you may go. The state’s abundance of clear, and relatively clean lakes and streams overshadow the fact that these areas need management and upkeep as much as any water body. For every clear and clean lake there is an equal number of lakes that are overloaded with nutrients, typically driven by a delivery mechanism yet to be controlled or fully understood.

    As I have explored the canvas of lakes management and furthermore the natural resources components that accompany these services over the past 20 years of my career I have realized just how dependent people are on use of the internet to begin their journey. While this is totally reasonable, there is no “paint by numbers” in this business. No replacement for experience or a trained eye coupled with applied education. Lakes are not houses, they are a living breathing ecosystem that is constantly evolving to achieve a balance, more particularly in the last few centuries this would include the heavy influence of man.

    So welcome aboard! Perhaps there is something that you can learn from my projects or the experience of others. I hope to have others contribute over time their expertise and input. To the maximum extent possible I will try to keep this website- blog less opinionated and more factual but at times it becomes difficult to hold the line when you are passionate about things, particularly decisions driven by others who are forced to look at things as black and white or place a financial line in the sand. So let us soldier ahead to discover our lakes, rivers, and everything else in between.

    -BV