Why Herbicides Are Wrong For Chautuaqua Lake

I am a long-time local biologist, conservationist, community member, and college educator, and have known and loved the waters, wildlife and natural beauty of Chautauqua Lake all my life. I spoke against the public funding of herbicides at the recent July 26, 2017 Chautauqua County Legislature Meeting, as did eleven others. In a recent editorial (Sunday July 30), I was quoted out of context and my true message was unfortunately lost.

Please let me be clear: I am speaking in opposition to the unnecessary application of the herbicides 2,4-D (Navigate) and Endothall (Aquathol K) to Bemus Bay and elsewhere in Chautauqua Lake.

How do I justify my position?

¯ Our lake is an old lake, rich in plant diversity and abundance of living things. Its well-established diversity of aquatic plants supports and stabilizes the natural communities within and along its shores, holds its sediments in place and provides food, oxygen and critical habitat for countless creatures. All are woven together in an amazing web of interdependency, complexity and connection.

¯ The Chautauqua Lake Partnership’s publicized goal of reducing weed and algal mats, “sludge” and disagreeable odors by applying herbicides targeting weeds, rather than most algae and blue-green bacteria, will likely be ineffective and is not an ecologically-sound solution. Dying and decaying macrophytes debilitated by herbicides will release additional nutrients into the water column for many weeks. Fewer macrophytes mean less shading and reduced competition for nutrients, which in turn will enhance, not reduce, algal and cyanobacteria growth. Herbicide treatment will likely be counter-productive in addressing the challenges of hazardous algal blooms and their toxins as well.

¯ The recent application of herbicides in Bemus Bay was not in accordance with the guidance entailed within the Chautauqua Lake Macrophyte Management Strategy (MMS). The MMS recognizes that Bemus Bay contains natural shorelines, unique plant communities, game fish spawning/rearing areas and several environmentally-sensitive areas where herbicide use is restricted. Herbicide application is specifically NOT allowed in game fish spawning and rearing zones prior to July 1. Unfortunately and inexplicably, the permit allowed both Aquathol K® and Navigate® (2,4-D) to be applied within a designated fish-spawning and rearing area (Zone 154) in Bemus Bay on June 26th, during the restricted period when egg spawning and young fish were present.

¯ The MMS specifies that use of 2,4-D (Navigate ®) is not recommended for the management of rooted macrophytes in Chautauqua Lake, and is not allowed in any environmentally-sensitive areas. In spite of this, according to the DEC permit, 2,4-D was applied in four zones in the Bay. Note that 2,4-D (active ingredient in Navigate®) is a systemic, synthetic herbicide intended in New York state only for emergent aquatic plants, not the diversity of submerged native and non-native macrophytes known to grow in Bemus Bay. According to several sources, this herbicide has moderate acute toxicity, is a potential groundwater contaminant, possible carcinogen and probable endocrine disruptor/estrogen mimic in certain amphibians and people. 2,4-D has been shown to reduce the rate of survival in ducks and waterfowl, is toxic to some fish and causes mortality in crayfish, many mussel species and certain insects and zooplankton. The other herbicide used, Aquathol K®, is known to be toxic to mammals. The product labels of both herbicides indicate that fish deaths may occur due to suffocation as weeds die, decompose and deplete oxygen. The fact that these herbicides were permitted by the DEC to be used during fish spawning and rearing season, and in a designated spawning and rearing zone, is regrettable.

¯ According to its pesticide product label, besides targeting the invasive Eurasian milfoil, Aquathol K® kills ecologically-valuable aquatic plants including coontail, native pondweeds, Najas, and water stargrass. Navigate® (2,4-D) targets milfoil and water stargrass, but may also impact white and yellow water lilies, elodea, duckweeds and coontail. Long-term toxicities on many aquatic animal species are unknown, although depending upon concentration and exposure time, toxicity and mortality are indicated for zooplankton (Daphnia), amphibia, crustaceans, insects (midges), molluscs and fish. No known studies have been done to explore the impacts and possible synergistic action of combining 2,4-D and Aquathol K® treatments. Aquathol K is “not acutely toxic” but may, depending on application rates and exposure, impact survival of crustacea, certain fish (bluegill, walleye), damsel and dragonflies, certain molluscs, and zooplankton. Clearly, these herbicides may have wide-ranging, harmful and unknown impacts on our lake’s web of life.

¯ Herbicides are poisons. Just because they are registered with the EPA and permitted by the DEC, and a certified lake management company like SOlitude applies them, it doesn’t make them safe. Interactions between pesticides have not been studied, nor have long-term, chronic effects. The Toxicity Word on the Aquathol K® label is “Danger,” while that for Navigate® (2,4-D) is “Caution.”

¯ EPA’s www.regulations.gov website and Office of Chemical Safety and Pollution Prevention note that Endothall (Aquathol K®) is a caustic chemical, skin sensitizer, and extreme irritant by the acute oral and ocular routes of administration. Dogs are particularly sensitive to endothall toxicity.

¯ 2,4-D is a skin, eye and respiratory irritant that can lead to headache, vomiting, diarrhea and kidney failure. It is a possible carcinogen (listed by the International Agency for Research on Cancer and associated with a slight increased risk for non-Hodgkins lymphoma in high exposure populations), potential groundwater contaminant, and suspected endocrine disruptor (www.pesticideinfo.org ). Studies are ongoing and the health implications are not yet clear (Wisconsin DNR 2,4-D Fact Sheet).

People, please be careful what you ask for. Because there remain so many unknowns about these chemicals, I urge all those who love the lake to please use the precautionary principle in decision making. A greater degree of informed awareness and action is critical, not quick-fix, herbicide-based solutions that are temporary at best, and may lead to unwanted health and ecological disruption in the long run.

Rebecca L. Nystrom, Professor of Biology (retired), Member of the Chautauqua Lake and Watershed Management Alliance Science Advisory Committee, and past-member of the Macrophyte Management Strategy Technical Review Committee.

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