What animal could have taken my trout?

[Monkstone]

I had 10 lovely rainbow trout all approx 5-7lb in a stream I dammed. Trout could not escape and water was not accessible to herons as no way for them to fly in and out under heavy tree cover. Stream ran directly into a pipe and cascaded onto beach 30yds away. No wildlife in stream source either as came from underground behind our property.
First sign of trouble was two trout on grass one morning this week. No marks on them just pulled out of water and left. Maybe one missing, all others seen - but timid and would not come up to feed.
The next night all disappeared despite me hanging CD's, chimes etc in trees and providing some light.
No trace of them at all. No signs on banking or grass of any struggle etc. Just an empty stream/pond!!
My only thought is otters, perhaps just one the first night and the whole family the next but they must be pretty big and strong to manage 7-8 big fish. Any other theories please?
This did happen a few years ago but fish were taken over a few nights and left mauled on banks. We do not have any problem during summer months.

[The Woodman]

Are you sure the exit and inlet were well screened in accordance with your EA Section 30 stocking consent - if your stream is in Engalnd or Wales?

I've known newly stocked Rainbows migrate seaward at a rate of fifteen miles over a couple of days and end up in estuarial waters of the Irish Sea. They may have even gone upstream even through culverts following a spawning urge.

Otters have no problem catching large carp and hauling 15-20 pounders out of the water and dragging them under cover.

Have you had a really good scout round to find the bodies or bits of them? Foxes will remove any fish found on the banks too and it's surprising how big a fish a mink can shift. I've sean eight pound salmon dragged underground by a mink through an unfeasably small hole.

[Monkstone]

Thank you for your reply. I think the answer can only be otter or mink. I was just shocked at the amount in one night with no trace. We have badgers and foxes in woods behind so they could have finished off any remains and, as you have confirmed, otters and mink can take large specimens this may explain it. I was convinced they were too big for them!
There is no possibility of trout escaping any other way. We have lost them in similar circumstances a few years ago but then it was classic mauling and leaving. We then left the water for a year so whatever it was did not return.
We gain consent every year to transport and stock up to 15 trout for our pleasure through summer months, ending up on our table/freezer in Oct. This year we thought we were safe to leave them longer as they were all a good size and the grandchildren did not want them caught.
It is a freshwater stream rising on our property with natural water fall at one end and large dam 40' further down stream. It is all under trees so safe from herons. Following inspections yearly earlier on, we now gain consent by written application as there in no possibility of us introducing disease into water course.
I think it is a lesson learnt that we take what we want earlier next year or put it down to nature taking its course. I hope whatever had them enjoyed them.

[Rye]

I would say mink in all honesty.

[Dogghound]

Originally Posted by Rye

I would say mink in all honesty.

How can you tell its not an otter?

[BloomingMarvellous]

Maybe they just jumped out, had a fish last year that kept jumping out the pond.

[The Woodman]

I am a little mystified by your sighting of two trout lying on the bank with no marks.

Is there any chance of human intervention under cover of darkness e.g. lamp and landing net?

[davecatt]

Originally Posted by The Woodman

I am a little mystified by your sighting of two trout lying on the bank with no marks.

Is there any chance of human intervention under cover of darkness e.g. lamp and landing net?

My thoughts exactly. For all to disappear over night without a trace I would say that of all possible predators the most likely would be human.
Dave

[Kayleigh]

Are you sure they are not hiding in the bottom.
I had a horses trough with 5 goldfish and some bricks in the bottom for cover and I could not see them until I changed all the water from the trough..
The stream you talk of sounds as though some of the fish could be at the bottom.
Just a thought..

[FUDGEY]

Id say Otter, Ive seen evidence of them taking fish over 35lbs! Only last week I took these photos of an Otter taking a Sea Trout of around 8lbs.