Excerpt from a Michigan Technological University Thesis
By Taylor A. Zallek, submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In Biological Sciences MICHIGAN TECHNOLOGICAL UNIVERSITY 2018
© 2018 Taylor A. Zallek
"We found that genetic diversity is greater in populations with no history of herbicide treatment, populations with histories of herbicide treatment have more admixture and evidence of hybridization, and plant communities appear to be differentially shaped by histories of herbicide treatment….Our results suggest that repeated exposure to chemical herbicides could be selecting for increased invasiveness among invasive watermilfoil populations. This could have drastic ecological consequences and implications for the efficacy of long-term management efforts of invasive watermilfoil."
Minnehaha Creek Watershed District (MCWD), Minnesota.
Feb 1, 2017 - Studies done by MCWD, University of Minnesota and Montana State University.
State of Michigan
"There are some downsides regarding herbicide treatment of EWM. Chemical control is usually at the cost of the landowner or lake association and may need to be repeated every 1-3 years for systemic herbicides (due to seed reproduction and growth and spread of any plants not treated earlier) and multiple times in a single season for contact herbicides. Over time, this can be a costly form of management and repeated applications using a similar treatment protocol could potentially induce a strain of chemically resistant EWM that could be comparable to Florida’s fluridoneresistant hydrilla (Michel et al., 2004).
“… commonly utilized aquatic herbicides (i.e., 2,4-D, fluridone) have been associated with milfoil hybridization events and increased herbicide resistance (Thum et al. 2012; Larue et al. 2013; Berger et al. 2015; Gill and Goyal 2016) “
Studies of Herbicide Treatments of Eurasian Water Milfoil from the University of Wisconsin
This list of references came was provided Aug 2020 by: Alison Mikulyuk, Lakes & Rivers Team Leader – Bureau of Water Quality, Wisconsin Department of Natural Resources
Phone: 608-264-8947, Alison.Mikulyuk@wisconsin.gov
Note that many of these studies are of lake-wide treatment, while the proposed herbicide plan for Crystal Lake is not lake-wide but spot treatment.
Is the cure worse than the disease? Comparing the ecological effects of an invasive aquatic plant and the herbicide treatments used to control it
A Mikulyuk, E Kujawa, ME Nault, S Van Egeren, KI Wagner, M Barton, ...
FACETS 5 (1), 353-366; Publication Year: 2020
https://www.facetsjournal.com/doi/10.1139/facets-2020-0002
"...multi-level modeling using a large data set revealed a negative association between lake-wide herbicide treatments and native aquatic plants, but no significant negative effect of invasive M. spicatum (Eurasian Water Milfoil). Taken together, our results indicate that lake-wide herbicide treatments aimed at controlling M. spicatum had larger effects on native aquatic plants than did the target of control—invasive M. spicatum. Our comparison reveals an important management tradeoff and encourages careful consideration of how we balance the real and perceived impacts of invasive species and the methods used for their control
Lessons from a decade of lake management: effects of herbicides on Eurasian watermilfoil and native plant communities
ER Kujawa, P Frater, A Mikulyuk, M Barton, ME Nault, S Van Egeren, ...
Ecosphere 8 (4), e01718; Publication Year: 2017
https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.1718
"...the results of an 11-yr observational study...our results suggest that while herbicide treatment can be an effective adaptive management tool, particularly in lakes with relatively recent M. spicatum invasions, the specific effects of individual treatments can be unpredictable. This study allows lake stakeholders to better understand the efficacy of herbicide treatment, in addition to the possible non-target effects on native macrophyte species."
Evaluation of large-scale low-concentration 2, 4-D treatments for Eurasian and hybrid watermilfoil control across multiple Wisconsin lakes
ME Nault, M Barton, J Hauxwell, E Heath, T Hoyman, A Mikulyuk, ...
Lake and Reservoir Management 34 (2), 115-129; Publication Year: 2017
https://www.tandfonline.com/doi/abs/10.1080/10402381.2017.1390019
"Although target species control was achieved with some of these treatments, variation in herbicide persistence, reduced control in many HWM (Hybrid Water Milfoil) populations, and nontarget impacts to certain native plants demonstrate the need for additional research and field studies."
Relationships between water chemistry and herbicide efficacy of Eurasian watermilfoil management in Wisconsin lakes
P Frater, A Mikulyuk, M Barton, M Nault, K Wagner, J Hauxwell, E Kujawa
Lake and Reservoir Management 33 (1), 1-7; Publication Year: 2017
https://www.tandfonline.com/doi/pdf/10.1080/10402381.2016.1235634
"Much time, effort, and money is put forth every year to combat the spread of this invader. We examined the long-term
efficacy of EWM management using herbicide and derived an empirical equation to quantify longterm treatment success for the lakes in this study. We found that lakes with lower pH (<7.5), conductivity (<0.1 mS/cm), and total dissolved solids (TDS <0.1 g/L) exhibited more successful long-term
management. Our results suggested that lake water chemistry may play a role in long-term herbicide management success of EWM."
Efficacy, selectivity, and herbicide concentrations following a whole-lake 2, 4-D application targeting Eurasian watermilfoil in two adjacent northern Wisconsin lakes
ME Nault, MD Netherland, A Mikulyuk, JG Skogerboe, T Asplund, ...
Lake and Reservoir Management 30 (1), 1-10
https://www.tandfonline.com/doi/pdf/10.1080/10402381.2013.862586
"This study is the first to link field-collected 2,4-D concentration measurements to selectivity
and long-term efficacy in EWM control following whole-lake management efforts. Although multiyear EWM control
was achieved with these single low-dose applications, longer than expected herbicide persistence and impacts to
native plants demonstrate the challenges facing aquatic plant managers and the need for additional field studies."