Yesterday I talked to a guy at the farmers market who said great blue herons were killing his KOI. He said since herons were territorial he put a heron statue in his KOI pond and hasn't had any problems since.
I am going to order a "Flambeau Great Blue Heron decoy" and see if it works. I am going to move it to a different spot on the pond every few days, supposedly this makes it a more effective deterrent.
