I used to live opposite a large lake where there were heaps of wildlife,waterfowl etc.
There were signs all over not to feed them however most people just ignored the signs.
One day, while walking my dogs which I did there every day, I happened to speak to a ranger and he told me that giving them bread is really bad for them.
I think this is quite well documented however people just dont care.
I DO NOT feed waterfowl.
I even had them on my property when I lived in the country and had a large lake on one side of the house and a river on the other -the previous owners had always fed the wild ducks bread however we did not.