Will ducks kill my koi?

[jupiter_moon_3]

I am so upset today, I went outside and discovered FOUR dead fish in my koi pond. My big black koi (Blue), my big spotted koi (Zest), my big white koi (Falcor), and my big fantail, Georgina. Georgina was the only one left from my original batch of fish almost three years ago. Also, a few weeks ago, I lost Cleo, a huge Oranda.

I hadn't lost a fish in a LONG TIME until Cleo! I don't know what could be causing this, but I can only think the ducks must be to blame, even if it's inadvertently, maybe their poo poisons them? As I said, I hadn't lost a fish in a LONG time, and Cleo died only a week or two after I got the ducks. I've only had the ducks for about two months. I'm so upset! I am afraid more fish will die. Does anyone know if this is their fault? I LOVE my ducks, but I love my fish, too!

 

[Denninmi]

Their droppings are very high in nitrogen. It certainly could do kill fish is they're in there long enough. Either directly through poisoning, or by causing a bloom that then sucks up the oxygen.

How many ducks, and how big is the pond?

I used to keep a LOT of koi, and I had some really great ones, so I know how awful it is to lose them. I gave up when the stupid herons cleaned me out. Sorry about your troubles.

I found that ducks and fish ponds, while nice in theory, do NOT work out. They trash the plants, muddy the water, harass the fish, and produce a lot of droppings that can be toxic.

Google "ammonia toxicity in fish" and "nitrate toxicity in fish" and you'll find a lot of articles about this issue.

Best solution -- keep the ducks away from the fish pond. They'll be just as happy with a plastic kiddie pool.

 

[Oregon Blues]

Ducks eat fish, so it is hard to imagine them killing fish without eating them.

The weather has been hot in many parts of the country. Not only is the heat bad for the fish, it causes algae blooms that are also bad for the fish and reduce available oxygen in the water.

I suspect that poultry and fish ponds need to be maintained separately.

 

[Miss Lydia]

Quote:
I have a small pond with pond goldfish. I use a dog xpen as a fence around it, if i didn't all my ducks would be in it, My goose was in it only once.I can see how their droppings could kill the fish pretty quick. sorry for your loss.

 

[jupiter_moon_3]

UGH I did not know this! I have had the pond for almost three years, it came with the house when we bought it. It's about an 1800 gallon pond, and I have a huge pump, it filters 3000 gallons per hour. THe fish are all MUCH too big for the ducks to eat. I got the ducks BECAUSE of the pond, ducks SHOULD have a pond, they're swimming birds, I wouldn't want to keep them out if it! It's like a catch 22, I had NO idea about this. Ducks and fish exist in nature together, including in natural ponds, it never crossed my mind. I'm going to post in a koi forum and see if there's anything I can add to the water to reduce the nitrogen levels... So sad! Thanks everyone!

 

[foxchasr]

So sorry for your loss. I have a pond smaller than yours with about 4 huge koi and about 8 goldfish, carp, etc. I have 2 6 month Pekins. When the ducks discovered the pond, the water turned from clear to pea soup in only a few days. The ducks would dive for the fish, but I feel it was more of them playing. There was no physical way the ducks could have eaten my koi, way too big. Out of nowhere, my ducks stopped going in the pond. I think the fish were nipping at their feet. I got 2 cement mixing tubs side by side and a kiddie pool and they are more than happy. I do also believe that if the ducks had remained in the pond longer, the fish would have died from the water being dirtied from the ducks. You have a much larger pond with a huge filter it sounds, so I'm not sure. I will also say that my ducks never wrecked my pond in terms of the landscaping around it, didn't mess with the plants, the majority of the damage was to the water. Again, sorry for your loss.

 

[jupiter_moon_3]

I just went out to check on everything, and my blue catfish, Punch and Judy, are both dead. Six in one day, seven total. I don't understand! I'm so sad about this... I think it's too late, and I feel like a murderer!

I always assumed ducks and fish would be fine, since they exist together in nature. I am going to head to the pond supply tomorrow if everyone else doesn't die tonight...

 

[TLWR]

Sorry about your fish loss.

Fish and ducks co-exist in large ponds. 1800 gallons isn't that large for a pond. Mine is 1000 gallons and there is no way fish would survive in there. The duck poop in the water, in addition to the heat, heaven for algae blooms. My water is a green brown gross color already and I have 2 runner ducks, so not even huge.
The huge pump will help, but it isn't going to be enough for them to coexist.

How long have the ducks been in your pond and how many? If they've been in there since the beginning and the fish are only now dieing, it is likely the heat that is helping to make your water 'toxic' to the fish.
Do you have any water testing supplies? If so, check your levels.
If you can, do a good sized water change.

 

[jupiter_moon_3]

The pond is about 10 x 10 x 2. I already had murky water, it's always been like that, no matter what I do, and the fish were never healthier. They liked the murky water I guess! It had been over a year since one died, maybe even a year and a half. I changed out a good potrtion of the water today, but I do find the more I change, the more fish die, even if I treat the water, so I have to be careful. Anyway, I have two ducks, a cayuga and a rouen, they're about three months old, this is my first duckie experience. They've been in the pond for about a month and a half, but they were tiny, so I'm sure the size of their poop has made a difference... Thanks everyone for your advice! I research koi care, I research duck care, never did I think I should research them both together until it was too late.

 

[lyleg5895]

If you want to do fish and ducks together, it's possible but very expensive and requires a lot of work and management. You'll need a MUCH bigger pond (think large swimming pool) and either have to do lots of treating of the water (expensive and labor/management intensive) or use natural methods via plant filtration (also expensive and labor intensive since you'll be planting constantly to replace what the ducks eat). Either way it's really not conducive for a backyard setup.