This commentary is by Ann Bove of Starksboro, who is an auxiliary board member of the Federation of Vermont Lakes and Ponds, and was the aquatic invasive species lead for the Vermont Department of Environmental Conservation from 2002 until she left state government in 2017.
We are fortunate in Vermont to have one of the strictest laws in the country regarding the use of a pesticide in water to control an invasive species.
Vermont law requires five positive findings for authorization to use a pesticide in water: negligible risk to public health, acceptable risk to nontarget organisms, no reasonable nonchemical control options, the development of a long-range management plan incorporating pesticide minimization, and that a public benefit can be achieved.
If one of these five findings cannot be made in the affirmative, by law, a permit for use cannot be issued.
Invasive species are “nonnative (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health” (1999 Executive Order 13112 – Invasive Species). They are a biological pollutant. Extremely difficult if not impossible to contain, control, or eradicate, invasive species can interfere with our ability to enjoy lakes, ponds, and rivers.
Dense stands of invasive aquatic plants provide unbalanced and substandard physical habitat for many fish species and macroinvertebrates due to the lack of mixed structure normally provided by a diversity of native aquatic plant species. These monocultures also pose a threat to game and nongame species populations alike and, via competition, cause losses or reduction of native plant species.
There is much scientifically supported evidence that native aquatic plant communities benefit significantly from aquatic invasive plant management. Control of invasive species like Eurasian watermilfoil protects recreational uses of our waters — boating, swimming, fishing — as well as the biological integrity of plant and animal populations of Vermont’s surface waters. Citing Vermont law 10 V.S.A, Chapter 50. §1451, “It is the policy of the state of Vermont to prevent the infestation and proliferation of invasive species in the state that result in negative environmental impacts, including habitat loss and a reduction in native biodiversity along with adverse social and economic impacts and impacts to the public health and safety.”
While some Vermont lake and pond users who fish may have adapted strategies to embrace a monoculture of Eurasian watermilfoil, research indicates such monocultures are not reflective of a healthy ecosystem and cause negative impacts over time, and supporting these monocultures does not reflect Vermont policy.
Vermont has over 120 species of native aquatic plants growing submersed in, floating on, or emerging from our lakes and ponds. Such diversity provides habitat and cover and is used as a food source by many aquatic critters. Aquatic plants — native or invasive — need light to thrive, just like plants that grow on land. In most Vermont lakes, the zone where light penetrates, and aquatic plants grow, is typically from shore to 20 feet deep.
Invasive aquatic species first turned up in Vermont in Lake Champlain in the 1940s, either because of our direct connection to infestations in New York via the canal system, via hitching a ride on recreational-based water equipment like boats and trailers, or via another pathway.
Some of our largest and most heavily used recreational lakes do indeed have infestations of Eurasian watermilfoil — Champlain, Memphremagog, St. Catherine, Bomoseen, Fairlee, among others. Many of these lakes are fortunate to have informed municipalities, active lake associations, and engaged lake enthusiasts dedicated to control Eurasian watermilfoil infestations as well as prevent the introductions of other invasive species, including invasive animals like zebra mussels and spiny water fleas.
However, roughly 75 percent of Vermont’s 800-plus lakes and ponds do not support an invasive species. Yes, 75 percent! Significant resources — time and money — are expended by many of our local communities to keep it this way. Preventing an introduction is far less costly than managing one, once an invasive species like Eurasian watermilfoil takes hold.
Use of a pesticide in a water body is nothing to take lightly. For many Vermont communities, this method reflects a last-resort control option. A decision to consider such use to manage an invasive aquatic species like Eurasian watermilfoil in a Vermont lake or pond should be community-based — whether one is a recent transplant or one’s history is rooted in Vermont for generations — and based on science and facts.
Before closing the door on Eurasian watermilfoil management, seek advice from known experts. The Vermont Lakes and Ponds Program is delegated to manage aquatic invasive species in waters of the state — species like Eurasian watermilfoil. This state program reviews submitted applications for pesticide use in water and must make the findings required by Vermont law to determine if a permit authorizing use can be issued or not.
To learn more about Eurasian watermilfoil, other invasive aquatic species and Vermont’s strict aquatic nuisance control permitting law, contact the Vermont’s Lakes and Ponds Program.
