Bill who putters wrote:
In article ,
"David Hare-Scott" wrote:

purplegirl wrote:
Hi, I am new to gardenBanter through desperation at losing all my
fish (30+) to a Heron. We have a decoy - obviously useless! but
wondered if anyone has had success with anything else? We want to
re-stock but only when we have made it safe from this horrible
bird. Thanks.

Net the pond.

D

Easy solution sounds way to go. However the smart monsters can walk
on a net forcing it to provide water for your fish to enter.

Support the net so that this doen't happen or make the pond deep enough so
they cannot get to the fish at the bottom, or both. And they are not
horrible birds or monsters, they are just trying make a living like any
other creature.

They
"blue Heron's" will wait and clean out a small pond. Fish to big to
swallow will just lose their eyes. Your fish Koi etc need a place to
hide.

Some water lillies or floating water plants will help here.

David