In Reply to: Sick swans posted by Black swan on June 10, 2012 at 09:38:38:

White Bread Is Bad For The Ducks Swans

If you are going to feed the ducks and swans it is best to give seed or brown bread.

A lack of nutrients in white bread can leave the birds crippled with a condition similar to rickets in humans. Their limbs become so weak that the birds are unable to dive for food.

Leftover bread in the water can lead to poisonous blooms of blue-green-algae, posing another danger to the birds. We would advise anyone who wishes to take down food to bring along brown bread instead. Potatoes, bird seed and carrots are also a much better choice.

The bottom line is their are no nutrients in bread for swans or ducks, it simply fills their tummies!
There are currently people feeding the wildlife and do not realize the harm it is doing. Maybe a sign could be erected with this information as I only found out about it recently.

Although ducks seem to love bread, it is not nutritious. White bread in particular is made from refined flour and is not proper for avian nutrition. Many Ducks suffer from degenerative liver disease because they eat too much. Also, leftover bread and Duck droppings pollute the water. The uneaten bread turns into a deadly mold called Aspergillus, which is fatal to Ducks, fish and other animals. Rotting bread can also breed other deadly diseases and parasites, particularly a Duck virus Enteritis, which with a single outbreak will kill all the Ducks of that area.
Feeding Swans and Ducks white bread is like feeding your dog chocolate.