No, Puma, they will not be back. If they threw a kitten to a pack of dogs, they will not be concerned about the ducks. Unfortunately, Turkish people do not feel the same about Birds as we do. They will just renew the ducks every year to bring in the tourists. The ducks that are left, will be quite tame so will come to humans easily and will probably be taken and killed for the table, unless someone goes and gets them and puts them in a river somewhere. Ducks are cheap, and the money they cost will be re-couped by all the tourists that love to see them, so they can easily be replaced every year.
If this where dogs or cats there would be an outcry, however, a few ducks will not be worried about.
If they are still in the area and anyone is around, ducks do not need to swim, but they do need to submerse their heads in water all the time to clean their eyes, if they don't they will get eye infections and eventually go blind.
I really hope someone can go and help them.