On Saturday I decided to go take a look at some of the streams closer to my house.  Most of them have been subjected to heavy farming and runoff and don’t look so hot.  They tend to be very muddy, have lots of algae and have limited bug activity.  From time to time when I am on streams like this one I have noticed foam on the water.  My first reaction when I see something like this is that it must be polution.  Fortunately I have a fly fishing friend who is a toxicologist.  He once told me that the foam is not pollution but a break down of organic material that is agitated by the stream.  Just in case you ever wondered about this there is a more detailed explanation on this site:  http://www.lakesuperiorstreams.org/understanding/foam.html