If you've been on the area lakes, including Lake Waconia recently, you will have noticed a large number of floating dead fish (mostly sunfish). It is a common thing to see in the springtime, as the waters warm and a common bacteria that affects fish can kill the weakened ones that have just gone through their stressful spawn. This year, with the up-and-down spring, the spawning patterns have extended longer than normal, which we believe to be the reason we are seeing a longer period of dead fish. The healthy fish you do catch are not harmful to eat. Here is a link to a full description of this common occurrence from the MNDNR...
http://www.dnr.state.mn.us/areas/fisheries/eastmetro/columnaris.html