Eurasian Milfoil

Doug Dicka
4/12/11
Eurasian Milfoil first originated in Europe and Asia and from there was introduced to the eastern part of the United States around the 1940’s. This invasive species is mainly transported from one water body to another by people that fail to wash off their boats when going from one lake to another one for any sort of recreation. Eurasian Milfoil is considered a very big problem considering the fact that it is all over the United States and it is very difficult to control and get rid of. When Eurasian Milfoil is introduced to a new body of water it can be very detrimental to the ecology of the lake. A few different ways that it can be bad from the aspect of people is that Milfoil will tend to form lots of vegetation on the surface of the water which makes swimming, fishing, canoeing, water skiing, and many other things a lot more difficult. These mats of vegetation are also a good habitat for mosquitos. These mats also tend to increase the sedimentation rate by trapping sedimentation. There are also many ways that this invasive species is detrimental to the other organisms in the same habitat. One of these ways is that this Milfoil starts its Spring growth cycle a lot sooner than other plants and it tends to shade out these other species that are good for the local environment. The diversity of the aquatic species in the same body of water also will decrease.
Milfoil is a species that will reproduce at a very high rate. Within two years of being introduced to a lake it will spread throughout the entire thing by being carried from one portion of the lake to another by water currents. Milfoil produces seeds that will help the plant to reproduce but the majority of the time the invasive species will reproduce through fragmentation. This is mainly how it is transported from one lake to another, when a portion of the plant sticks to a boat and is not removed before going to another lake.
Once Milfoil is established to a certain point within a lake it is very hard to get rid of if not impossible. In small bodies of there are a couple of different types of herbicides that are used to combat the invasion. The two main herbicides are called “Sonar”, and “triclopyr-TEA”. There are other types of removal options as well. These include: underwater rototilling, hand pulling by divers, the installation of bottom barriers, and diver dredging. Another way to get rid of Milfoil in a small body, such as a pond, is to drain the pond before winter and this will kill the species. Although this is very effective it usually takes up to two consecutive winters to achieve. All in all between people who pay to get rid of this species for private use and the cost to the state it comes out to be over a million dollars per year to try and contain, and get rid of Eurasian Milfoil.