I remember packing up old bread and cereal and taking my children and grandchildren to ponds and lakes to feed the ducks. It was alot of fun.
Well, now it is dangerous and sometimes deadly to feed the ducks. Bread crumbs are contributing to botulism in ducks. Visitors who feed bread crumbs to the ducks are helping to create an environment that breeds the bacteria. Increased fecal matter; warmer pond water and overfed birds also help spread the illness. The bread goes straight through them and is not mobilized as a food source. They poop too much. So, if there are signs that say "Feeding Ducks/Wildlife Prohibited", there is a good reason.