Paul wrote:

The wife bought a small goldfish at the weekend and put it into our
pond, well, to say pond its more like a large water feature really which
we have to attract wildlife.


If thats its main purpose it not a good idea to put fish in it at all.

I know we have newts in the garden and we have plenty of birds too, is
it likely that blackbirds or newts would eat a small goldfish

It's more likely the that the fish will eat the newts (or at least their
larvae).

Anita