Pond Boss Forums INTRO Questions & Observations Dead fish in my pond

I have a pond about 9 acres big. There is a lot of 8-9 f.o.w. with the deepest around 14. There is a small creek that will run into the pond when the rains come. There is a small about 8 inch culvert water goes out at the spillway. Water is usually crystal clear. Last year we treated it extensively to kill the weeds since they had taken over and made even going across the lake impossible. The water murked up some but the bass were very healthy. After ice out (last week), today I went to the pond and there were a few hundred dead fish around the dam. All were bass and bluegill. One dead bass had a bluegill stuck in its mouth. They were scattered over the dam as we had some major rain in the northeast part of Indiana last week. Walking around the lake, I saw a few fish in the shallows but didn't even get a good enough glimpse to say what kind they were. I thew out some live bait on a bobber and didn't get a bite. I also tried a jig and didn't raise a fish. This lake was loaded with 12-16 inch bass and a lot of stunted bluegills that could hide in those weeds.

Is this a normal thing? Should I be concerned? What steps should I take? There is an aerator on the neighbor's property. (There are 4 houses around the lake. I haven't built out there yet. That is why I just now went out there.) Can anyone reassure me or has this scenario happened before?

Worried in northern Indiana,

Jonesy

Welcome to the forum!

A lot of guys in your area experience a winter kill of fish. It appears sadly your pond did as well. The bass with a BG in his mouth is unusual, I am not sure how he relates to the other fish... I would guess there are still plenty of fish left alive in your pond.

Howdy, Jonesy.

How long did the fish appear to have been dead, in your estimation? Were they well discolored/covered with mold/chunks missing off of them, or fresher looking?

The simple presence of aeration won't, unfortunately, guarantee no Winterkill. It needs to be sized and run properly to help rather than hinder fish health. My windmill aerator didn't stop me from losing a bunch of large BG & RES while we had ice here for a month and a half.

The fish looked like they were dried out. So I would guess they had been dead for awhile, the ones on shore. The ones still in the water were bloated and not very moldy but looked like they had been dead for awhile also.

I know fish die off in the winter but there were quite a few fish. I know there were a lot of fish in the water, and most fish were of varying sizes. There were no fish floating. They were washed up on dry land from the water level dropping after the rains or right on the bank.

I will know more when it warms up here a bit and I can get out and do a little recon.

Jonesy

The spring after the summer that we had "professionals" kill our weeds my fish were decimated. It took years to get the pond back. They were dead on the bottom in the spring, it was gut wrenching.

This spring, I had some dead frogs, and one big bass a few grass carp and cats, a lot of BGs but they all floated. I did not use my aerator this winter because I've heard both good and bad about them, and why pay the $$? Also rule #1 is do no harm, so I left it off.

I personally feel the key is to have the fish fed in fall, and depth, lots of depth. Snow on ice is a killer.

In your case, the newly dead plants in your pond from the treatment you got may have caused even more loss of DO and may have helped lead to your fish kill...

No doubt snow on ice for prolonged periods is a killer! Lots of guys lost fish this year. Sorry for your loss...

Was at the pond tonight and saw some swirls in the water from fish. Not sure what they are but they didn't die so it gives me hope.

How should an aerator be used in the winter?


Jonesy

AngolaJones,

Join the club. Lots of ponds and even some small lakes had winterkill this year in our area. I came very close in one of my ponds but fortunately had the foresight to check D.O.levels with an oxygen meter. I caught it when D.O. levels were close to critical and had a a large surface aerator to not only jump start D.O levels but open up some ice. Your problem may or may not have been exasperated by decomposing vegetation under the ice from when you sprayed your weeds.

As you know we had more snow than usual this winter and it laid on the ice longer than usual. And we had ice up earlier than usual too. Most likely light was blocked out with the snow long enough to stop photosynthesis and start a decline in available oxygen in the pond. The oxygen in your pond is like a bank account: there is only so much and if new oxygen is not produced, and ice out does not occur before it's depleted, you're in trouble.

Most likey you did not lose all your fish but sadly the biggest ones are the first to go.

As far as prevention I would put a diffuser in the shallow end of your pond in winter to keep an area open to allow light in and to allow noxious gases to be vented. Go to a the aeration category for more information. It doesn't have to run 24/7 either.

This was certainly a bad winter for fishkill. I have gotten A LOT of calls from people all over the North who are realizing fishkill as their ponds deice. As Cecil mentioned, an aeration system doesn't have to be running all winter, it can be started after there is ice and snow cover. If properly designed, an aeration system can open the ice in a matter of hours and then be shut off - then the ice will form again, but it will be clear, allowing sunlight to penetrate. Correct Placement of the diffusers is important, too, so make sure you consult a professional before installing an aeration system for winter.