Divergent responses of cryptic invasive watermilfoil to treatment with auxinic herbicides in a large Michigan lake

  • Published source details Parks S.R., McNair J.N., Hausler P., Tyning P. & Thum R.A. (2016) Divergent responses of cryptic invasive watermilfoil to treatment with auxinic herbicides in a large Michigan lake. Lake and Reservoir Management, 32, 366-372.


Action: Use herbicide to control problematic plants

A before-and-after study in 2014 in a lake in Michigan, USA (Parks et al. 2016) reported that native northern watermilfoil Myriophyllum sibiricum was present before, but not after, a focal herbicide application. survey points (frequency: 0.2%) before herbicide application, but was not found at any survey point three months after (frequency: 0%). Statistical significance of this change was not assessed. Meanwhile there was a significant decline in the frequency of non-native Eurasian watermilfoil Myriophyllum spicatum (before: 2%; after: 0%) and hybrid watermilfoil M. sibiricum x spicatum (before: 21%; after: 16%). The same was true for abundance at each survey point (data reported as an abundance score). Methods: In June 2014, herbicides were added to 428 ha (5%) of Houghton Lake: 339 ha of 2,4-D-amine (29 kg/ha) and 89 ha of triclopyr (15 kg/ha). The lake had been treated with herbicide intermittently since 2002. Watermilfoils were surveyed with a rake before (June 2014) and after (September 2014) the focal herbicide application, at 996 points across the lake (including some in areas not directly treated with herbicide).

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 19

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust