A few more ideas: If you can't make your pond deeper, stack wall stones around it so that raccoons have to reach farther to catch the fish, or build hideaways for the fish using pavers set on cobblestones (Home Depot sells 4" grey ones). Although they weren't attractive, we also sank some 4" PVC "hubs" (pipe connectors) in our pond. Better yet, get some large PVC hubs/elbow connectors and balance a large paver on top. There are commercially-available hideaways, but read the reviews first because many aren't positive.
My cat was freaking out about something outside this morning, and I opened the patio door expecting to see a neighbor's cat. Instead, I saw a fox looking for birdseed on one of my tray feeders!