Pictured above from left, Eurasian watermilfoil and curly-leaf pondweed, which are the most prominent invasive aquatic plant species in Chautauqua Lake.
MAYVILLE, N.Y.: -- Ecology and Environment, Inc. (E&E) recently provided Chautauqua County with a white paper on available aquatic plant management techniques for managing weeds in Chautauqua Lake. The report, which was released in June 2019, is entitled, “Summary of Methods for Control of Aquatic Invasive and Nuisance Plants with Special Emphasis on Eurasian Watermilfoil and Curly-leaf Pondweed.”
“We were pleased to have this independent, third party firm evaluate various approaches to address the weeds in Chautauqua Lake,” said Mark Geise, Deputy County Executive for Economic Development. “It is important that we have an approach to periodically evaluate our decisions and goals for Chautauqua Lake, and E&E’s white paper will help us establish best management practices for our Comprehensive Lake Management Strategy.”
E&E, a consulting firm in Lancaster, N.Y., prepared the white paper through in-depth research and examination of peer-reviewed papers, environmental impact statements, text books, herbicide product labels obtained from the New York State Department of Environmental Conservation, and management guides and guidelines.
The white paper, which has an emphasis on the available herbicides that could be used in New York State, examines various biological, chemical, and physical aquatic plant management techniques to help control the amount of Eurasian watermilfoil and curly-leaf pondweed (the two most problematic plant species) found in Chautauqua Lake. It also identifies the advantages, disadvantages, and environmental impacts associated with each technique from a third party perspective.
Since 1937, there have been 51 aquatic plant species identified in Chautauqua Lake. While most of the plant diversity consists of native species, there is an abundance of Eurasian watermilfoil and curly-leaf pondweed in the lake. These two highly invasive, non-native, aquatic plant species were first documented in the lake in 1972 and 1937, respectively, and continue to have an impact on the health of Chautauqua Lake.
To control these aquatic invasive plant species, the report recommends to:
- regularly monitor plant communities to track herbicide results and plant regrowth in order to make informed management decisions,
- utilize the most effective combinations of available biological, chemical, and physical management techniques and tools available, and
- rotate herbicides used at a given site in order to prevent herbicide resistance in targeted plants.
“E&E brought a very balanced perspective to their analysis,” said Pierre Chagnon, Chautauqua Lake and Watershed Management Alliance Chairman. “They observed that aquatic plant management tools and techniques are classified as physical, chemical, or biological. All of these tools and techniques come with advantages and disadvantages and have environmental impact. Management approaches should be selected based upon waterbody-specific economic, environmental, and technical constraints, and should fit the site-specific management goals.”
Some of the physical management techniques that have or could be pursued are mechanical harvesting, hydroraking, hand harvesting, dredging, and water level control. Biological techniques that have or could be implemented are the introduction of fish, insects, or pathogens that will impact the targeted plant species.
The report also identifies chemical techniques by reviewing nine herbicides registered in New York State for use on submerged aquatic vegetation. These herbicides include: copper, diquat, endothall, florpyrauxifen-benzyl, flumioxazin, fluridone, imazamox, triclopyr, and 2,4-dichlorophenoxyacetic (2,4-D).
“E&E found that herbicides can be a selective and effective management technique against Eurasian watermilfoil and curly-leaf pondweed,” said George Borrello, Chautauqua County Executive. “However, as identified in the report, it is important that herbicides are not the only tool in our toolbox to restore Chautauqua Lake. We need to make sure we are using other non-chemical techniques in conjunction with herbicides in order to effectively control invasive weeds while having minimum impact on non-targeted species.”
To view a copy of the full report, visit www.co.chautauqua.ny.us/186/County-Executive .