Hello. We own a park and marina in Texas. We've had a family of swans begin coming to our park several times a day. There are 2 adults and 4 younger ones. Still gray, but getting fairly large now. They parade right through our swim area full of adults, young children and kids playing & swimming. They are starting to get aggressive towards our guests. How to I get them to go farther up or downstream without hurting them? Is there something I can put on our property where they won't come on land here any longer? I can't take a chance of a young child getting hurt by one of them.