Do any readers know anything about frogs and tadpoles?

Last year, our pond had loads of frogspawn, then the tadpoles disappeared overnight.

Later, we learned there was a disease about called red-legs which kills frogs and found three that had been affected in this way.

This year, we had four loads of spawn again in the pond. You could see the tadpoles wriggling about. Then, one morning, they had all disappeared, the same as before, with the spawn left floating on the surface.

We have two rather fat fish who also live there and lots of newts. Could they be eating the tadpoles?

Can someone enlighten me about this problem?

-Mrs V M W Osborne, Rushlake Close, Coldean