duckweed prevention on a pond
what are good ways to prevent duckweed and cattail growth on a small pond without causing harm to wildlife. I have many kinds of frogs and toads and muskrats and turtles and assorted ducks and birds as well. I would like to keep them safe but also need something that will prevent the green duckweed from covering the whole pond. we had it last year but previous years the pond was clear. I am looking for safe ways. so far I have found one chemical (claiming to be safe) and one natural method to order online and am looking for recommendations for what will be effective without harm.
Dakota County Minnesota
The MN DNR is the responsible agency for aquatic species. Here is a good webpage of information about duckweed:http://www.dnr.state.mn.us/shorelandmgmt/apg/regulations.html
You might want to also contact Steve Enger from the MNDNR about your specific question. HIs contact information is on this webpage.