This first link is the Fall 2012 PLM newsletter. There are a couple of interesting articles about the abundance of weed and algae growth last year and a trial treatment for zebra mussels. This is good news and I hope you find time to read it.
This second link is from The Michigan Riparian. It describes a few invasive species of plants and what can be done to control them.
You may have to click twice to get to each article.