GardenBanter.co.uk - Fish dissapeared...help?

Hi people, I have a one acre pond, natural vegatation and spring fed.

Water quality is good. late spring last year I stocke dit with 200
bass, 500 sunnies and 2000 fat head minnows. All were good and
healthy and at the end of the summer, I could tell that lots of
reproduction had taken place.

Well, we had a hard winter, the pond was frozen over for a good part
of it (NY state, Region 5), the deepest part of the pond is 27 feet
deep, by taking cores I found that the ice only froze to a depth of 2
1/2 feet.

Now that it has thawed and the water has warmed a bit, I have seen
10-15 dead fish bodies, buthave seen *no* other fish in the pond (used
to be, you couldn't go anywhere and see a cloud of them).

There are a plethora of turtles, newts and frogs alive int he water.

COuld it be that the fish are all still at the bottom of the pond? If
so, what is the proper water temparature that I shoudl be seeing them?

Is it possible that *all* of the fish died over the winter? If so,
what coudl I have done to stop that?

Any ideas, pointers or guesstimates?

Thanks in advance.

Bill