To stock or not to stock, that is the question

[spandit]

I have a fairly large pond (1/2 acre) which we use for swimming and wildlife. I'd like to be able to eat fish (trout) from it but I've heard that they're not good for other wildlife, presumably because they predate on insects, tadpoles etc.

We have a heron visiting quite often but the pond is very deep in places so hoping the fish will be able to escape into the depths, or is this wishful thinking?

 

[Robson Valley]

Trout have to eat like everybody else. Of course, you can expect predation, same for the heron. Deep water won't save the trout for long. The productivity of the pond means they will be cruising for food. All the Heron has to do is stand in the shallows and wait. They are quite good at that. One sharp beak-bop in the head and the trout is much more manageable to pick up and swallow.
Just a few trout won't make them a common and popular prey item for the Heron.
Trout have low survivorship/high mortality. 50% if the population is gone in 15% of the life span.
I advocate doing the experiment. How much would 100 trout fingerlings cost? Are going to have to be licensed up your whazoo to keep trout? Do a little to restructure the food web in the pond. Gives you something new to look for if nothing else.

 

[Stew]

I literally just finished watching the episode of Clarksons Farm where he made and stocked a pond. I’m cynical as to how well they’ll last in his!

 

[Kepis]

Speak to the local Fisheries Team at the Environment Agency, they will advise you of the best way to proceed and help you get things like a stocking consent and licence, advise re the appropriateness of your plans vs the site, for instance if the pond has an overflow that runs to a local river (no matter how far), you may well have stocking restrictions.

On the ponds i look after, we cannot stock anything that's not naturally in the R Adur, despite our outlet being a seasonal stream that only runs in winter time and being miles away from the river itself.

Herons are the least of the problem, it's Cormorants in the winter time that are the issue aka the Black Death, you may not have any around now, but it wont take them long to find a new food source ie: your pond.

 

[spandit]

I literally just finished watching the episode of Clarksons Farm where he made and stocked a pond. I’m cynical as to how well they’ll last in his!

That was some of my inspiration but I've wanted them for a while. His pond is not very deep so there's little protection for them.
I have the necessary permit - it's a simple form to fill in and it came back the same day.

I've never seen a cormorant here but thanks for the heads up

 

[Broch]

I used to manage the 'pond' for a private fly fishing consortium up here in Mid Wales years ago. I would think it was a similar size if not slightly bigger. We would typically stock about 100 rainbow trout every six weeks or so. It was 'lightly' fished however, typically around 6 people each day on a weekend and a few during the week (I could have the pond to myself most weekdays). The catch limit was four so it was quite easy to remove most of the fish but there were always plenty in there.

Anyway, the reason for saying all this is, despite the fact the trout do eat just about anything that moves in the water, there was still lots of wildlife in the pond. However, it will be a balance - stock it so it's easy to fish and you'll see less wildlife; lightly stock it and the trout will be harder to catch

Oh, and stock size will make a difference - big fish will eat more - we typically put in 10oz trout; some grew on to be 1.5Lb without us feeding.

We occasionally got some wild brown trout in there as well - lovely fish but typically only about 8oz - they all went back of course.

 

[Pupers]

Not sure if anyone has mentioned Otters, once one finds you have stocked with Trout, he/she will not stop until they are all gone………Which won’t be long.

A minimum 10’ at the deepest point, Trout need to escape into deeper water during a hot period.

 

[Broch]

Not sure if anyone has mentioned Otters, once one finds you have stocked with Trout, he/she will not stop until they are all gone………Which won’t be long.

A minimum 10’ at the deepest point, Trout need to escape into deeper water during a hot period.

Ah, but I would stock trout to have otters visit my pond.

Seriously though, we never had an otter problem - what we did have were mink.

 

[Pupers]

Ah, but I would stock trout to have otters visit my pond.

Seriously though, we never had an otter problem - what we did have were mink.

Your gonna need a fat wallet to keep that up! I once stocked 150 small trout into a stew pond, when we went to net them out into the larger lake………They were all gone! Lots of Otter prints around.

We have a healthy population of Otters here in Devon, not so many Mink around now.

 

[Toddy]

O.T. but the local countryside rangers were talking about mink and otters, and they said that when otters moved in on the rivers and burns, the mink took to the land instead to get out of their way. On land the mink are much more vulnerable to foxes, birds of prey, etc., and thus the otters really do control mink numbers....and that meant that more wildfowl survived.
They reckoned otters were a good thing even if the anglers do rant about them taking salmon when they have to catch and return.

 

[Lean'n'mean]

If the pond has some kind of natural balance, it might not be a good idea to introduce a non -native (Rainbow tout) predator into it. If it's a commercial enterprise or if it's just a dug hole hole in the ground filled with water & you don't mind it changing then fine, but one should always be wary of introducing species which don't belong into a natural enviroment, because what looks like a good idea on paper may turn out to be a pain in the butt. And if you have to start feeding them that will bring another load of problems.
Just something to think about.

 

[Toddy]

Does it need to be trout ?
Is there not something else native that would do well though ?
Bream ?

 

[Broch]

Does it need to be trout ?
Is there not something else native that would do well though ?
Bream ?

I think he fancies them on the grill now and then

 

[Toddy]

I'd actually thought at first that he was just stocking the pond and thought of vendace/powan and the like, then realised my mistake.

Are carp not more usual stock for food though ?

 

[bobnewboy]

I'd actually thought at first that he was just stocking the pond and thought of vendace/powan and the like, then realised my mistake.

Are carp not more usual stock for food though ?

Not unless you’re in Eastern Europe, or doing a medieval re-enactment

 

[Robson Valley]

If the pond has no natural inlet or outlet, it's really nothing more than a gigantic aquarium. Ideal situation for ecological experiments.

 

[Kepis]

If the pond has no natural inlet or outlet, it's really nothing more than a gigantic aquarium. Ideal situation for ecological experiments.

But still subject to the laws of the land which specifically prohibit the stocking of any water with fish or other aquatic species without the necessary movement permits, stocking license, health checks, eco impact surveys and assessments, invertebrate surveys etc etc etc.

You can't just go chucking fish into a pond or water way because in your opinion its an "Ideal situation for ecological experiments".

Total recipe for disaster and subject to either heavy fines or time at Her Majesty's pleasure for the most serious offences.

 

[Broch]

@Kepis - am I right in saying all stocked trout (rainbow or brown) must now be sterile (triploid)? All those rules have changed since I was stocking our lake.

 

[Kepis]

@Kepis - am I right in saying all stocked trout (rainbow or brown) must now be sterile (triploid)? All those rules have changed since I was stocking our lake.

Exactly that, rules changed in 2015 iirc

 

[Robson Valley]

I apologize. I forget how politically complicated your environment has become.
Our situation is simplistic at most.