Cecil,
No, I don't have any reason to think that. It is just very surprising to me that even the pike minnow (what are called Squaw fish around here) also seem to be gone. I also did not see any dead fish on the surface after the ice melted as I had in years past from winter kill. My pond is very close to a main road (see arial photo) and I have also told several people who have asked that they could not fish my pond so it made me wonder if someone decided to poison it - just paranoid I guess ; ). We had a very hard winter with lots of snow so you are probably correct that it was winter kill. It just amazes me that I have not seen any baby or adult pike minnow - those things are very hardy fish. We usually spend much of the Summer trying to fish them out.
As far as the water testing, I was referring to water testing just for general water quality not for poison.
