Something is killing my fish!

[pondkeeper]

I have recently suffered some deaths due to mouth rot and finally thought I'd sorted out my pond. Then I found a small goldie with a wedge-shaped "bite" taken out of his head. Funnily enough he still seems happy enough swimming around with one eye. Still, I thought Heron?

Sadly, a few days ago I found a dead goldie with a suspicious looking wound in its side. I had a good look at it and it definitely looked like something had had a go at it (rather than disease) but it was slightly larger than I would expect from a beak attack (and not very deep).

Then today I have just buried one of my very first fish I bought, a lovely shuby, with a very large chunk taken out of its rear end. I've attached a photo as I really am not sure what could have caused it. It does not look to me like a bird attack and as it is on the underside of the fish that would tend to suggest it was attacked from underneath... There was some plant disturbance but I can't rule out the wind for that. We have a koi around 10 inches which is relatively large compared to the others. Have koi ever been known to attack other fish? Even if they have he seems very docile and doesn’t ever go after the others when I’m around. Plus we have a load of babies at the moment so I would have thought he’d just eat them if he got peckish.

I would be very grateful if anyone could help me find out what's going on here so I can prevent the loss of any more of my little friends. I've thought of heron deterrents and netting, although I don't really want to cover the pond all the time as there's not a lot of point in having one if you can't see it.

Thanks for any help!

 

[RSFish1]

How big of pond do you have? Any chance you have a turtle in there or coming in to there? Usually a raccoon or a opossum will eat a lot more then that if it gets it mouth on it. This is a real shame. Looks like something has a big mouth to take a bite like that. How big is the fish in the picture and the width of the bite?

 

[Oldhead]

I'm kinda leaning toward turtle. Do you have another water source near by?

 

[pondkeeper]

Thanks for your replies. I meant to add last night after having a closer look at the photos that it actually might not be a bite, given that the edges of the wound are so smooth and have not broken the flesh. It almost looks like it has just wasted away. Does that fit in with any known disease?

To answer your questions the fish wasn't very big, around 4 inches (sorry, I should have put something to scale against in the photo). The “bite” was therefore about 3/4 inch (if I've got my maths right!).

No, there isn't another water source nearby, just lots of fields. I should have said also that the pond is in north London, UK, so racoons and opossums are a bit scarce. Turtles are not common (as far as I know) but I had considered that as a possibility. The pond is only 3000 litres though and about a metre deep in the middle so I am pretty confident I'd be able to see the little bugger if he was still there.

Having said that, I tried to fish around in the bottom today and stirred up a hell of a lot of sludge. On a side question, without a bottom drain, is there any way to clean this out and prevent it in future with chemicals or do I have to buy a vacuum? I try to take out as much detritus as possible but obviously I'm not doing a great job!

Thanks again for all your help!

 

[hewhoisatpeace]

There's a way. http://www.aquaart.com/drain.html

Pretty cheap, very effective. Without a bottom drain or a pump in the deepest part, you are poisoning your fish slowly, and that stuff gets pretty septic and disease causing.

Put 'retrofit bottom drain' into a search engine and you'll get a lot of information on this, and how to install one pretty cheap. Good luck, Pondkeeper.

 

[pondkeeper]

OK, stupid question then - if I buy a longer hose and move my pump to the bottom of the pond, will this solve the problem? It was down there before though and there was still lots of sludge after winter. The pond developed a major blanketweed problem in spring and I ended up draining the whole thing and cleaning out the sludge that way.

Sorry to have gone off the main topic by the way, still am keen to hear any thoughts about my poor fish being eaten away...

 

[stroppy]

what type of pump have you got pondkeeper ?
it looks a big like some kind of fungus probably because of all the muck in the bottom ... you could try netting some of it out but you really need your pump or a vac of some sort to get it out and water changes would help have you tested the water ?

 

[hewhoisatpeace]

Kind of have to sweep everything down to it.

 

[pondkeeper]

Sorry for taking a while to get back to you. I have got an Aquamax 12000 pump running to a Filtoclear 15000 (Filtoclear Set 4).

Don't mind putting my pump at the bottom if that will solve the problem, or else leave it on the shelf and get a bottom drain to attach to it if that's a better plan. I've tried scooping out some of the muck and have got a bit out. Doing a bit every day to try and minimise the stress on the fish.

I'm also using some Sludge Control solution (Interpret or similar) - is this any good? Are there any other better ones or are they all the same and slightly gimmicky?

The water conditions are fine as far as nitrites etc. are concerned.

 

[stroppy]

i would put the pump on the bottom to help get that muck out .. but you will need to clean your filters more till its off the bottom ... i would also do some small water changes to dilute it, i have used the sludge buster i think it helps with a small amount of sludge... someone else might be able to help you more ... you might also need to treat the fish with something

 

[stroppy]

tetra pond medifin cures fungus and parasites... but you do have to airiate your pond while useing it