Home Values on Invasive Plant Infested Lakes

I am a Realtor and the president of a lake association in Maine. I am doing a survey of homes which are located on invasive plant infested lakes. The State of Maine is last to become involved  with this problem.  Currently there are 29 lakes infested with Milfoil with an approximate total of all lakes in Maine at 6000.  I would love to know any information from Realtors and property owners how this has or is effecting sales and values on their lakes throughout the U.S.  No statistics are available in Maine to track this.