Missing koi in pond - hiding or gone forever?

[OllieOtter1994]

Hi all

New poster on here!! I have a fair few questions about our pond and it feels a bit of a mystery at the minute!

Our pond is a ¼ acre in size, has a silty bottom (but lined with clay) and lots of weed – although we did make an effort to clear a lot of it out last year, around 80% of it. It has always been crystal clear as far back as we have been here (over 60 years).

In the last 10 years we have stocked with silverfish - there are now hundreds of roach! Last year we also branched out with 9 gold grass carp, 4 tench, some goldfish and shubunkins and 3 koi carp. The koi carp were a fairly decent size – probably 12-16 inches.

However since adding the koi to the pond we have not seen them once, they were added around October of last year so when the weather was turning – we figured they were at the bottom of pond (it gets 5 foot deep in the middle and hard to see from the bank).

Now that the weather is starting to get out, we’d expect to see the fish again, but we haven’t seen any grass carp (we could often see at least 7/8 of them on the surface last year), still no koi and also now a lot less goldfish / no shubunkins. Presumably the smaller fish have been made heron food… The kois however would surely be too big for the heron, as well as being in the deeper parts of the pond / out of sight in the winter months?

We have also had brief encounters with cormorants and once with an otter. Which is odd given there are no nearby streams, I wonder how deadly one visit would be, I,e, would it be likely to decimate all the larger fish in the pond before moving on? We did not find any trace of any dead bodies although there are built up / bushy areas near the pond which could potentially hide a body.

However, we do have some hope the koi may be somewhere in the pond still, the water has been clouded up almost completed (its never been like this before) – is there a chance the kois could still be in there? Would 3 kois even murky up the waters that much on a quarter acre pond? Or is this down to there being less weed in the pond?

Having fished for carp a lot I'm convinced we would've seen the kois on the surface by now, but my father feels they are still in there given how murky the water is now...

I’d really appreciate if people could recount their experiences with such issues and offer their advice!

Thanks!

 

[420benz]

Now thats a pond.

 

[Jhn]

Large koi and carp can muddy the water.

Hard to say if they are in there as the otter would most definitely go after 16” fish. Although a heron would have trouble eating a 16-18” fish it wouldn’t stop it from stabbing at the fish to try and catch it to eat.

Koi won’t necessarily come to the surface especially if they are getting plenty to eat at the pond bottom and the pond has plenty of oxygen.?This is where/how they naturally forage for food(downturned mouth).

Nice looking pond by the way.

 

[Lisak1]

Heron don't really care if the fish is too big to go down their throat... they will stab and kill them anyway and discard the body. But don't lose hope - your fish may just be very good at hiding and you may see them yet !

 

[addy1]

One spring I thought all my fish were gone, they were hiding, around 100 never saw one. Then one day they showed back up and my pond is no where as big as yours.

 

[cas]

What a beautiful pond @OllieOtter1994 !

 

[OllieOtter1994]

Thanks all for the nice words!! Although I can't help but think it would look much nicer with the koi cruising around on top in this hot weather...

Appreciate your thoughts, this gives me some hope, I imagine there would be a quite a lot for the koi to get stuck in to at the bottom with the weedyand silt. Maybe even the grass carp have gotten a taste for the deeper depths of the pool having been down there all winter... That's perhaps a bit hopeful, as we could clearly see them on the surface all of last summer.

Interestingly all the roach and remaining goldfish are happily surface feeding now the weather has started getting warmer, I would've expected therefore to have seen at least one of the grass carp!

In any case, I've placed an order and we've got 18 grass carp coming soon - green ones this time so they'll no doubt be a bit more heron-proof... Will take some pics before they go in! Look forward to seeing them get to 20lb! Although given the numbers of roach they may find some stiff competition for food (I said 100s of roach but its probably more around the 1000 mark..).

 

[Tula]

Beautiful pond, looking forward to you sharing more pictures

 

[OllieOtter1994]

Hi all

Little update, bought some goldfish and 3 small carp yesterday. One is a ghost/mirror with really nice scaling - probably won't be able to pick them out now they're in the pond but hoping in the next couple of years we'll see some biggish shadows cruising near the surface!!

18 small grass carp and a few kois (if I can add them to the order) to come in the week!!

Cheers

 

[OllieOtter1994]

Hello all, had the delivery come this morning. 18 baby grass carp and 3 little kois!

 

[addy1]

Nice!

 

[JamieB]

Best of luck with those. If they disappear, or if you think it’d be smart, put up some trail cams around the pond to hopefully see what’s been going fishing

 

[OllieOtter1994]

Hi everyone

Have been a bit slack updating – apologies!

The fish mentioned in my last post seem to be settling in well, although I have not been able to monitor the pond so well in the last couple of weeks and have lost sight of one of the koi (the white one) which I used to see daily - and who had grown a lot. I’m a bit concerned the heron may have got this one, but I’ve noticed the koi go through cycles of residing in different spots so hopefully he is just elsewhere in the pond. Unfortunately we had a seagull visitor which took some of the smaller goldfish as well. The 18 grass carp have not been spotted but were only 2-3 inches so I expect it will be a while before we see these guys.

However, we’ve made various additions to the pond since the last entry.

Firstly, we bought 65 goldfish off a local who was selling them cheap, all in great condition and very bulky in size. I’d say the average size of these fish to be somewhere between 8-10 inches with some over a foot big.

Here are some pics

For the most part they seem happy and healthy, and tend to group together in the centre and bask in the sunlight most of the day. Sadly, we have lost about 5 of these now, with 1 or so dead fish showing up each week roughly since adding them.



Secondly, we spotted another ad for some carp (2 ghosties, 3 koi and 1 grass) and 11 goldfish going cheap. We have also added these to the pond but unfortunately the condition of these fish were less so. Some of the fish are deformed (presumably from being in such a small pond), and I’ve noticed them not looking entirely smooth when swimming.

Ghost mirror – about 7lb

Koi – 1lb

Koi 2lb ish

Ghost common – 4lb

Grass carp – 1lb

The grass carp above has a large growth on it which is buoyant and preventing the poor fish from going below the surface – can’t be nice for him!



Thirdly, to help oxygenate the water we have fitted an aerator. I am not sure how much of a problem the oxygen levels were but given we were losing fish it seemed appropriate. Here it is in action!

Questions

Does anyone have any ideas why we’ve lost these fish? We have had the water tested (all sound) and now fitted an aerator to help oxygenate the water. However, given there is a LOT of weed in the pond, and we have had no trouble with the roach (there are hundreds/thousands) I do not certainly believe the oxygen levels would be the issue, but I am unsure what else this could be. Some of the fish have shown signs of physical damage, but I believe this may have only been after the fact (i.e. likely a water vole / rat or moorhen picking at the dead body and nothing predatory).

Can goldfish and koi carp adapt from being handfed food all their lives to feeding naturally? We throw food in but for the most part the roach take the food, as we also can’t get food easily out to the centre where the majority of them are.

Can anything be done to remove the growth on the grass carp?

Will the fish with swimming deformities heal over time - will he stop swimming on the wonk?

Thanks in advance for your help all - much appreciated!

 

[addy1]

Wow those fish have got to be happier! A nice big place to live. Losing some after being moved, water changes, temperature, ph etc is normal. The deformities, hard to say if they will get better and no idea on the tumor.

Feeding, there is plenty in that pond for them to feed on, I would not worry about feeding. Also that way they don't get used to coming to a spot for food that might make them better prey for birds.

 

[OllieOtter1994]

Cheers for that addy. Yes certainly happier, I'd say you could visibly see a sense of freedom / happiness overwhelm them when we first added them! Its good to see them with more than enough space to patrol in a natural-looking setting. Hopefully this freedom will kink out the deformities but perhaps not.

Noted RE the food. I should mention that we added the roach (small silverfish) about 8 years ago, and they have since bred and multiplied and now dominate the pond. I'd guess that there are around 2000 of them in there - average size of about 3-4 inches but up to around 8-10. Presumably this is the natural 'peak' / equilibrium population of the pond - and by adding these goldfish and carp (some of which are very large), I've upset the balance.

Should this be a concern? Or is there likely to be plenty of room for these additions? In any case we have stepped up the hand feeding so this should make up the difference.