I've used bottle rockets with some success.
Once they show up with young I just use the bottle rockets to keep them away from the feed when I am feeding the fish. Otherwise I leave them alone. Eventually they move to another pond overland as they hate the bottle rockets.
Lucky for me there is a high school pond they all seem to congregate at. What really floors me is they will walk back and forth about 3/4's of a mile across yards with dogs to get there with young in trail.
Very intelligent and adaptive birds. Usually smart enough not to get hit by cars with some exceptions. Amazing they were once hunted almost to extinction.
A pair with three or four goslings doesn't bother me on my four ponds. I enjoy watching the young mimic every thing the parents do. I just can't have them sucking in the floating feed.
