Eurasian water milfoil invading Minnesota lakes

This article submitted by Aaron Ziemer on 7/14/98.

Eurasian water milfoil is not just a Twin Cities lake problem anymore. In the past month Lake Minnewaska has been discovered to have the exotic weed.

The milfoil was found in the Starbuck marina of Lake Minnewaska, but traces of the weed have been found at the mouth of the marina, so it is in the major part of the lake as well.

Two other lakes in that same area have also been discovered to have it. They are Gilchrist Lake in Pope County and Oscar Lake in Douglas County.

The exotic weed survives best in water that is about 10-15 feet in depth. Lake Minnewaska has over 2000 acres of water near or in that range.

Eurasian water milfoil cannot be eradicated. The growth of it can be slowed down, but it would be almost impossible to get rid of the weed completely. The chemical that is used to slow the growth of the weed is 2-4-D.

One of the reasons it is so tough to get rid of the weed is because of its ability to reproduce. Every time a boat, water skier, swimmer, or even heavy waves travels over the exotic weed it can be spread.

Eurasian water milfoil looks fairly similar to the native northern milfoil. There is a difference in the number of leaves in a grouping. Eurasian milfoil has anywhere from 12-21, and northern milfoil has just 5-10.

Eurasian water milfoil is also very costly to control. It is also very difficult to control it in areas where tourism and recreation are popular.

To help control eurasian water milfoil a boat owner should check for weeds and leaves on the boat and boat trailer each time the boat is taken out and put into a lake.

Boats are a major factor in the spread of exotic weed growth and people should know what to look for when taking boats into different lakes.

When eurasian water milfoil becomes thick enough it can almost make sheets of weeds in the water.

Another big problem with the exotic weed is it can make area beaches unattractive.

Recent attempts by the DNR to help stop the weed from spreading have controlled the problem to an extent.

The DNR now has 10 years of experience trying to fight the exotic weed, but still there is really no hope for eradication of the weed.

Some groups are pushing a law that says the DNR should do spot checks to see if the weed is on any of the boats and fines should be issued if there is some found.

Eurasian water milfoil has now spread to 85 Minnesota lakes, most of which are in the Twin Cities, but the problem is also rising outside of the cities as well.

Return to Archives