Fish died during the winter

[Skip]

I live in Ohio, and had several large Koi in my 3 x 6 or so pond, which have done great for years. At the start of the freeze, all of my fish ended up dying- probably 15 total. The fish shop said it was probaby due to the weather being warm, then cold ect., to where they could not get to their hybernating state. This was very dissapointing, and I want to prevent this in the future. Does this make sense? Other factors that I wonder may have been the cause was a bird feeder very close to the pond- bird food or droppings falling in? Also a golden chain tree at the edge- I found this morning that the seeds may be poisonous, maybe some dropped in, exept this is the 2nd year for the tree, and no issues befor now. Does anyone have any opinions?

Thanks!

 

[c2c7390]

hmmm...do you know the water temp that they started dying

 

[DrDave]

My first thought are the seeds dropping into the pond. With a pond this small, why don't you cover it with something to keep out potential threats? A big patio umbrella would easily cover this pond.

 

[Skip]

As far as the temperature of the water, the top of the pond had just frozen over. We found the first fish when the water began to thaw. There was quite a bit of freezing and thawing at the start of the winter. The fish shop said that they had others call with similar problems.
The seeds were the first thing that I thought to correct. I move the bird feeder to an area further from the pond. A covering to prevent other seeds may be a good option.

 

[DrDave]

I don't buy the warm and cold theory. There are millions of ponds all over the world, both natural and man made. Most of them have no problems such as you have described. I would look at toxins first. It may have been rotting debries in the bottom or even a single dead fish that died of natural causes that started it.

 

[bunnymp]

I also find the weather a weird conclusion. Have you tested the water for quality? Amm, pH, etc?
Did the fish appear to have been sick before their demise? Any fungus or tail rot?
Did you use benefical bacteria during the winter?
When was the last water change?

 

[Skip]

The last water change was in the fall. The fish did not appear sick, but the pond was frozen over apparently when they died. I didn't see any signs of fungus or tail rot when I cleaned the pond out a few weeks ago. Since the water was so bad from all of the fish, I didn't test it either, just found a lot of seed in the bottom. The seed is what seems different than from every other year that the pond was cleaned out in the spring, and no problems in previous years. Looks like this may be the culprit, what do you think?

 

[DrDave]

The debries that is trapped on the bottom rots and when it freezes over, the gas has no place to go, so it stays in solution. It is important to make sure your ponds bottom is clean before allowing it to freeze over.
We don't have that problem here, but if I did, I think I would consider a bubbler and a soccar ball to keep the oxygen up an the top open.
A tarp, suspended over the top, to keep out other elements is another method I might use.

 

[Skip]

Thanks for your help! Hopefully I'll have better results next spring with everyones help and advice.

 

[pondlady]

DrDave is right the gunk in the pond releases gas as it breaks down if there is no hole in the ive so it can escape it builds up and kill every critter in the pond.Cover it before the leaves fall be sure and cot off all plants that are left in the pond. Put an air pump under the cover to protect it from the weather , place the air stone 12 " below the surface. This allows for greater bubble action at the surface thus keeping the ice open. This is my covered ponds, the hump in the middle is the house for the air pump it keeps both pond open all winter, No dead fish come spring. The other is the same shot late summer.

 

[oldmarine]

PondLady,

Thanks for the great pictures of your pond. I'm a visual person and seeing the real thing or pictures really helps give me great ideas as to how I would like to have my next pond look if and when I can rebuild.

All of you ponders have been quite helpful, thanks.

 

[PHYLAL]

I also think the weather was not the problem. Unless there was an unnatural sudden temperature change this should not be a problem. I live next door to you in Pennsylvania and can concur to a very unusual winter.

I know that there are certain types of seeds that are indeed toxic to fish, but can not tell you all of them. The list that I have does not include ‘Golden Chain Tree’ but is only a partial list. Some seeds, while not toxic, can swell and plug the digestive tract.

I would think toxins in the water the most likely cause (although there are dozens of other possibilities).

I had a bad experience this year due to the weird weather. We had a strong wind storm that literally covered my pond with leaves. That night the pond froze over and I could not remove them. It never thawed again until this spring, what a mess cleaning them out. I kept the pond open somewhere all winter and lost only one fish. I never found the remains so it may even have been lost to a critter. I was so relieved when the ice finally thawed enough this spring so that I could see the fish.