Thanks for the replies...

Gotta assume the bird theory is the culprit...the pond is off the road outta sight...never had anybody on or around it...I live on the property and it's relatively isolated from neighbors and never had anybody ask to fish it...will still take advice and stay mum to see if anybody fesses up though...guess I gotta put my 9 year old to work weeding out Bullheads and I'll work the "Greenies" over with a fly rod all summer...sure was frustrating to find them after all I went through to eradicate and start over...oh well, guess that comes with the amateur Pond Meister gig ! Anybody want some free "Greenies" and Bullheads ? \:\)