Being under a major migratory flyway do something preventive before they
arrive. Once fed they are harder to get rid of. Motion sprinklers are easy
to install, maintain and other than maybe getting hit yourself till you
remember, give you total access to the pond, visually & physically. ~ jan

http://www.km01.com/gardeninghome.html Scarecrow sprinkler

I look forward to seeing pictures - sounds wonderful!

I should have known that. thanks for the info. Now if I can just survive
any potential heron onslaught! I live close to a major migratory flyway, but
haven't seen any in my neighborhood.
(Do you know where your water quality is?)