Tizsas Mum - It was a matter of irony when I read your post - we have recently installed a newer and bigger pond and all five of our fish had been happy as the proverbial Larry since the move and have been more active than we have seen in a long time. The day of your post - we too thought they had all disappeared
We were concerned a Heron or other bird had got them - but thought it unlikely that would all disappear on the same day. We have been monitoring daily - and the good news is we had a sighting yesterday!!
we think it could be that they have either gone back into semi-hibernation (we have got two drain pipes for them to hide in) or that they have been spooked by the barley straw parcels that have been floating around.
In case it is the latter - we have tonight weighted them down to stop them moving with the waterfall 'tide' and hope we see more of our little pals in the next day or so.
Hope yours pop up and say hello to you soon - I'm sure they will! x
I have an update....
My neighbour has been noticing a lot of his smaller goldfish disappearing. His large, established pond is teeming with Koi and other fish - but this year he has been puzzled.
Although the heron does try and visit - his pond is well netted and he couldn't understand why they were going - so he set his garden camera up and discovered the culprit - a grass snake!
I don't think this is what has got ours - I still believe they are skulking at the bottom but may be worth looking out for.
Thank you all for your replies, but good news....I spotted one big one today, and two of the baby ones two days ago. I didn't think the frog scenario was unlikely, because the tadpoles were there for at least two weeks before the fish disappeared, so the adult frogs long gone. I think maybe a heron spooked them and they are (all hopefully) hiding at the bottom among the weed and lilies. Unattractive as it may look, may have to net the pond.
I have had a goldfish pond for the last decade and every year we have hundreds of babies produced.
The problem with garden ponds is that there is little cover for the fry so they invariably get eaten by the adults. Generally speaking, if a goldfish can get something in its mouth it will eat it.
We have had Herons take a few of the adults even through a full net, but it's the enemy within that accounts for more casualties than any from above!
Well thankfully, today I have seen one of the larger ones skulking under the lilies, and counted 3 babies, so all is not lost. Earlier this year around March time, I saw the big ones up one end of the pond and counted 15 babies down the othe end, which is how it was last Autumn, so I still have hopes that I may have 3 adults and some babies. Time will tell.
Don't forget that tadpoles, as soon as they grow legs, become carnivores and will eat fish fry and small fish.