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Aquatic Plant Information, Tools and Research

APM Resources

The DNR is committed to the study of aquatic plant communities and aquatic plant management (APM). We evaluate and report on APM activities, provide public education and outreach related to aquatic plants and have developed several lake management tools. Here you can find many useful resources put together by the program and its partners.

The Value of Aquatic Plants
Resource Description
A Peek Beneath the Waves An article in a 2014 issue of Wisconsin Natural Resources magazine about the benefits of aquatic plants, the history of APM in WI, some of the work DNR has done related to aquatic plants, and the importance of APM planning and working with lake users.
Distribution and Abundance of Aquatic Plants – Human Impacts This 2014 book chapter written for Earth Systems and Environmental Sciences provides an overview of the factors influencing the ecology and abundance of aquatic plants as well as aquatic plant management.
Embracing the benefits of aquatic plants. 2020. An article in the Wisconsin Natural Resources magazine about the benefits of aquatic plants, department outreach efforts, the history of APM in WI, and current APM practices.


Aquatic Plant Identification
Resource Description
Through the Looking Glass This is a popular field guide to aquatic plant species found in Wisconsin, to which many Wisconsin researchers contributed.
Aquatic Plants of the Upper Midwest: A photographic field guide to our underwater forests A field guide of Wisconsin's aquatic plants, complete with color images and similar species.
Species Fact Sheet: Starry Stonewort A fact sheet on non-native starry stonewort species identification.


Understanding Invasives
Resource Description
Brittle Naiad Species Summary A 2023 factsheet on brittle naiad life history, distribution & spread in Wisconsin, potential impacts, and management options.
Curly-leaf Pondweed Species Summary This 2023 factsheet provides an overview of curly-leaf pondweed life history, distribution & spread in Wisconsin, impacts, management options, and prevention techniques.
The Science Behind the "So-Called" Super Weed An article from Wisconsin Natural Resources magazine published in 2016 about the status of Eurasian watermilfoil (EWM) in Wisconsin's waterbodies, including variations in EWM abundance over time and between lakes.
Factsheet: EWM Research Facts and Long-term Study A 2010 factsheet about the status and effects of EWM in Wisconsin's waterbodies.
What Can Plants Tell Us? The first two pages in this 2009 issue of Lake Tides describe a little bit about DNR's long-term study of aquatic plant communities in lakes around the state.
Research overview: long-term trends in unmanaged populations of Eurasian watermilfoil A 2021 factsheet on long-term trends in unmanaged Eurasian watermilfoil (EWM) populations. It shows that EWM populations are often small, variable, can increase through disruption events, and are not necessarily associated with lower native plant species richness.
Research overview: hybrid watermilfoil and herbicide resistance A 2021 factsheet on hybrid watermilfoil and herbicide resistance. It provides an overview of research on hybrid watermilfoil response to commonly used aquatic herbicides, discusses potential mechanisms for spread of hybrid watermilfoil and herbicide resistance, and emphasizes diverse plant control strategies and integrated pest management.


Evaluation of APM Activities
Resource Description
Effects of 2,4-D Application on Early Life Stages of Fish This 2022 factsheet provides an overview of several research studies that examined the effects of exposure to ecologically relevant 2,4-D concentrations on the early life stages of several freshwater fish species. Altogether, the research results suggest that exposure to 2,4-D, even at concentrations legally permitted by the Environmental Protection Agency for use in Wisconsin lakes, can have a negative effect on the survival, behavior, and cognition of early life stages of fish.
Homeowner Perceptions of Aquatic Invasive Species: Results from a survey of lakeshore property owners in Wisconsin A 2021 report on a survey of 747 Wisconsin property owners about their attitudes towards aquatic invasive species (AIS) and the approaches used to manage AIS. It shows that although most homeowners are very familiar with AIS and AIS prevention techniques, they are often unaware of APM activities that occur on their lakes and are unfamiliar with management options for established AIS populations. Respondents overall also reported very negative attitudes towards AIS and felt that the benefits of monitoring for AIS outweighed the risks.
Control of Invasive Aquatic Plants on a Small Scale. This 2015 article in North American Lake Management Society's (NALMS) LakeLine assesses the efficacy of small-scale 2,4-D treatments for Eurasian watermilfoil control. It describes situations that may warrant small-scale treatment, shows that small-scale control outcomes are highly variable as a result of rapid herbicide dissipation off the target site, compares granular and liquid 2,4-D formulations and emphasizes APM planning and integrated pest management.
Factsheet: Small-scale Herbicide Treatments for Control of Invasive Aquatic Plants A 2014 factsheet describing important considerations for small-scale herbicide treatments in aquatic environments, including concentration and exposure time, dissipation of herbicide from the targeted treatment area and others.
Herbicide Treatments in Wisconsin Lakes. This 2012 article in NALMS LakeLine provides preliminary results of nine large-scale, low-dose 2,4-D herbicide treatments. It describes the potential benefits of spring treatments and observed variation in treatment efficacy, effects on native plant species and water quality and slower herbicide degradation rates.
Factsheet: Large-scale Treatment Research in Wisconsin A 2011 factsheet describing important considerations for large-scale herbicide treatments in aquatic environments, including dose, efficacy, longevity of results, non-target effects and others.
Factsheet: Turville Bay Project Highlights from a study comparing chemical and mechanical approaches for management of EWM and restoration of native plant communities. 2011.
Getting It Right: Whole-Lake Herbicide Debate Deserves a Dose of Science The first four pages in this 2005 issue of Lake Tides describes assumptions associated with Eurasian watermilfoil and whole-lake fluridone treatments, as well as the science behind them.
Starry Stonewort Management - Frequently Asked Questions This 2020 document contains answers to frequently asked questions about starry stonewort management. It includes answers to questions about management approaches, timing and efficacy.
Starry Stonewort Management - Statement of Department Efforts A statement by the DNR in 2020 regarding starry stonewort management efforts in the state. This statement includes general information on preliminary data and collaborative research efforts.
Starry Stonewort Management Factsheet A 2023 factsheet summarizing the monitoring and evaluation efforts implemented by the DNR in collaboration with a variety of partners.
Is the cure worse than the disease? Comparing the ecological effects of Eurasian watermilfoil and the herbicide treatments used to control it A 2022 factsheet on a recent study evaluating whether the negative ecological effect of lake-wide herbicide treatments used to control Eurasian watermilfoil (EWM) exceeds the negative ecological effect of EWM itself.


Tools for Assessing Lakes and their Plant Communities
Resource Description
UW-Extension APM Guide: Aquatic Plant Management in Wisconsin This guide to APM, developed by UW-Extension and many of our partners, was written for anyone interested in conducting APM. It provides a walk-through of the APM planning and permitting processes, descriptions, pros and cons of various control strategies and much more.
Recommended Baseline Monitoring of Aquatic Plants in Wisconsin: Sampling Design and Laboratory Procedures, Data Entry and Analysis, and Applications This document describes DNR's standard protocol for assessing aquatic plant distribution and abundance in lakes. It provides instructions for conducting a point-intercept (PI) survey, obtaining PI coordinates and uploading them to a GPS, vouchering specimens and more.
Plant Point-Intercept Survey Data Entry and Analysis Form [XLS] This Excel spreadsheet should be used to document data collected during PI surveys of aquatic plants. It includes instructions for use and once data has been entered, provides automated summary statistics of the data.
Spreadsheet for Comparing PI Survey Presence-Absence Data [XLSM] This Excel spreadsheet can be used to compare aquatic plant presence-absence data over time. It may be used to assess differences in the plant community before and after management and evaluate plant management outcomes.
Draft Fact Sheet: Guidance for Implementing Small Scale Spot Treatments and Design of Herbicide Concentration Monitoring Plans This draft protocol can assist in designing small-scale aquatic herbicide treatments and monitoring herbicide concentrations following treatment.
Draft Fact Sheet: Design of Herbicide Concentration Monitoring Plans for Whole Lake Herbicide Treatments This draft protocol can assist in designing an herbicide concentration monitoring plan following a whole lake herbicide treatment.
Aquatic Plant Treatment Evaluation Protocol This protocol is designed to evaluate the response of the aquatic plant community following an herbicide treatment or any other ecosystem manipulation. This protocol can be used to monitor whole-lake or small-scale aquatic plant management (APM) activities on lakes.
Annual APM Industry Meeting Materials

2023 APM Industry Meeting

The 2023 aquatic plant management (APM) industry meeting was held on January 31, 2023, via Zoom. The webinar video and presentation slides are available below.

Webinar Videos

Presentation Slides

2022 APM Industry Meeting

The 2022 aquatic plant management (APM) industry meeting was held on January 27, 2022, via Zoom. The webinar video and presentation slides are available below.

Webinar Videos

Presentation Slides