One of the most serious problems in lakes today is Eurasian watermilfoil (Myriophyllum spicatum). Hundreds of millions of dollars have been spent to control milfoil with weed harvesters or toxic herbicide, and its growth is now worse than ever. Weed harvesting has proved ineffective in controlling Eurasian watermilfoil, as fragments made by the harvesters quickly growth new plants. What is little known is that Eurasian watermilfoil can be easily and economically controlled using environmental remediation without unhealthy herbicide.

Eurasian watermilfoil was first introduced to a pond in Washington, DC in 1942, and to the Midwest between the 1950s and 1980s. The United States Geological Survey believes that Eurasian watermilfoil was introduced as a food source for waterfowl. It prefers nutrient-rich lakes, ponds and reservoirs. Eurasian watermilfoil forms tangled mats of weed growth both up to twenty feet below the surface and up to the surface of the water, and crowds out native aquatic plants. Eurasian watermilfoil interferes with swimming, boating, fishing and waterskiing.

Characteristics of Eurasian Watermilfoil:

Eurasian watermilfoil is a particularly nuisance weed in northern climates. Its ability to reproduce from fragments and spread rapidly, its high growth rate in a large range of temperature and environmental conditions, and its tendency to reach the surface and form extensive mats at the surface can allow this milfoil to shade and out-compete native vegetation. Eurasian watermilfoil starts spring growth sooner than native aquatic plants and can shade out these more beneficial plants. The sheer mass of stagnant milfoil can create a good habitat for mosquitoes. Milfoil mats can rob oxygen from the water by preventing the wind from mixing the oxygenated surface waters into deeper water. This can limit the growth of snails that would feed on the organic sediment if oxygen were available. Oxygen-depleted sediments release large quantities of phosphorus and nitrogen, averaging three times the amount coming in from watersheds. The dense mats of vegetation also increase the sedimentation rate.

Eurasian watermilfoil does not only receive its fertilizer from the sediment, but also from the water column, having only a filamentous thread by which this milfoil attaches itself to the bottom. This milfoil can grow just as well whether the thread is attached to the bottom or not. Eurasian watermilfoil has the ability, unlike most native plants, to reproduce from one-inch fragments made by boat motors or during weed harvesting.

Eurasian watermilfoil can extract carbon dioxide directly from the water or from carbonates in the water, which gives this milfoil a definite advantage over many other plants that can only absorb carbon dioxide from bicarbonates in the water. Other advantages are its one-year faster seed germination period than other plants. Most aquatic plants germinate after one or two years, instead of during the first year. Eurasian watermilfoil has the ability for the seeds to withstand drying for one year, compared to 3 – 4 months for other plants. Its fruits withstand freezing. This milfoil reproduces asexually. Milfoil has the ability to grow in more alkaline waters and to grow up to two inches a day.

As with other plants, however, Eurasian watermilfoil has weaknesses that make this milfoil subject to environmental remediation without the use of toxic herbicides. This milfoil must grow in nutrient rich water. It needs high levels of ammonia. The water must have high alkalinity. This milfoil also requires large amounts of carbon dioxide, either in the free form, or in the bicarbonate form. Robert Wetzel, a leading limnologist wrote in his book, Limnology, that Eurasian watermilfoil is highly dependent on light, so dark colored water limits its growth. This can change rapidly, as lakes switch every few years from algal growth to weed growth, and from weed growth to algal growth, depending on which become established earliest in the year.

Eurasian watermilfoil can grow in up to twenty feet of water. The dense weed growth prevents wind and waves from oxygenating a large portion of lakes and ponds from spring until fall. While aquatic plants exhaust oxygen into the water during the day, they take up oxygen when photosynthesis reverses at night. The presence of organic sediment in a lake or pond confirms a lack of oxygen at night and during extended periods of the year.

Environmental Remediation of Milfoil without Unhealthy Herbicide or Ineffective Weed Harvesting

Eurasian watermilfoil likes carbon dioxide and as you know, shaking a bottle of pop removes carbon dioxide; and so does the CLEAN-FLO International inversion system. Removing carbon dioxide from the water shifts bicarbonates in the water to carbonates in which the carbon dioxide is unavailable for plant growth. This controls milfoil by environmental remediation without harmful herbicides. The CLEAN-FLO system has been in Sweeney Lake in Minnesota since 1973 and there is no Eurasian watermilfoil in Sweeney Lake today, although it is most of the neighboring lakes. But if the CLEAN-FLO inversion and oxygenation system is turned off, there is nothing else that we know of to prevent Eurasian watermilfoil from coming into Sweeney Lake.

We have asked our CLEAN-FLO International representatives if Eurasian watermilfoil was in any lakes they have treated, and is it in any Clean-Flo-treated lakes now. The answer from all of them was always the same: “Yes, Eurasian watermilfoil was in several lakes and ponds that we put the Clean-Flo system in, and no, it is not present in any Clean-Flo-treated lakes or ponds now.” Eurasian watermilfoil can be controlled using environmental remediation without unhealthy herbicide. With toxic herbicides, the milfoil comes back, usually worse than before and must be poisoned again. With environmental remediation, Eurasian watermilfoil never comes back.

Before and After images:
Lake Greenwood, Greenwood New York
Before	After
Lake Collins, Scotia New York
Before	After