PLP,
As someone that raises perch and has had them for years there are two things that may make you feel better about your perch:
1.) They are a very tough fish and are hard to kill
2.) If you aren't fishing close to the bottom you won't catch them. They are a bottom oriented fish and if you have enough oxygen they will be in the deepest water of your pond close to the bottom.
I would try a slip bobber adjusted 1 foot of the bottom with worms or small minnows.
That said just dumping fish in is not a good idea.
