There have been a few threads with good info on heron control here, but I can't find them right now or remember what section they were in.

However:

Cecil Baird has had pretty good success deterring Great Blues by placing brightly colored lines 1-2' off the ground around his ponds, I believe just inside and outside of the waterlines.

Great Blue Heron decoys should be available from either Cabela's or Bass Pro, if you want to try them. I remember folks reporting they had some success with the decoys, IF they kept moving them around.

Large, boisterous free-roaming dogs (Labs are a favorite) who like to run off Herons may be the best solution, if you have one.

I have personal experience with Great Blues (one at a time) and Green Herons (singly or in pairs). A couple of incidences loud noises accompanied by small objects moving in excess of 2000 fps passing close by their heads will frequently convince them to bother someone else's pond. On the other hand, I currently have a Great Blue who can see or hear me leave the house, whereupon he flies off for a while and returns later.

While we hate to lose any fish, realize that herons do a relatively small amount of damage compared to the colonial fisheating birds (cormorants in particular).

"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
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