Pond Boss Forums INTRO Questions & Observations Recent Fish Kill, Not Sure Cause (7 acre)

We live in OFallon, IL, and i'm the President of this association that live on a lake. There are 24 homes on this lake, and we all contribute yearly by an annual fee for all the upkeep, etc. There are 7 aerators in the lake/pond. It is just under 7 acres and evidently the deepest part of the lake is only about 15 feet. Pond has been here for between 30-40 years. Oldest member that lives on the lake was here when it was built.
It gets rain runoff, that is what feeds it lol.

This past Saturday morning, the fish started dying. Pond had been stocked with bluegill, bass and some grass carp. OH and catfish too. They are all dead. Yesterday i spent all morning and evening collecting all the dead fish because well only a couple people were helping (that is for another story lol).
We don't know why this happened, we suspected a lake turn over. We have not treated it with anything, so we know it is not that.
Now.....there has been an increase in Geese population the last 2 years. For the last 2 years evidently the lady that would addle (sp?) the eggs has not done it, so now we have an increase. This spring i counted about 25 babies lol.

We attended a pond management seminar earlier this year put on by a local college in conjunction with the DNR. The DNR guy that spoke was so knowledgeable, and helpful. Wow.
I sort of inherited this role, and have been in the house only 3 years this fall.

So managing the lake/pond is new to me.
We have collected all we can and dug holes in the ground to bury the fish.

We just don't know what caused this. The guys that have been here the longest have said they have had about 3 or 4 fish kills in about 25-30 years. And that every time it happens they just go around and collect the fish and bury them.

I'm wondering if the overly populated geese and the poop they have, have contributed to the biology of the lake.
Let me post a couple of pictures of the dead fish we pulled out. Even a few grass carp, and some really large catfish (about 8-10lbs i bet).

In the mean time, i'm searching through this forum to help educate myself and us that live on the lake so that we can take care of it.

Thanks for listening.

Do you have any harvest records or is this more of a catch and release type lake?

What prompted you to add more fish?

Hi there, it is a catch and release lake. We have not added fish in a few years. Not since i been here. I'll have to look up when we last added fish.

Here's my guess. Fish kill was likely caused by overpopulation vs poison goose poops. While catch and release is great fun without the removal of fish overtime they will overpopulate and die as a result. Fish kill happened right after a stressful event (hot summer temps)?

There are some ways to help with this....Fishing derby for the kiddos, scout troop (boys or girls or both). Team up with a local shelter to see if they would take fresh fish after so it doesn't go to waste.

Could go for an annual electro shock survey where all fish are removed...

Encourage the people that fish the lake to report what they catch and please take some home to fry them up....

I'm completely guessing though. I live in the KC area and we just had some really warm weather roll through. Guessing you guys got it too. One of the other more experienced guys may have a different opinion but from what I've read it sounds like nature decided to clean out the garden. The good news is that Nature abhors a vacuum and those remaining fish will refill the pond.

Pics

Thats quite a load of floaters for sure.

The lake has 7 bottom diffusers for aeration? Unless they are malfunctioning or improperly sized, then you would not have a turn-over.

It may not be all goose poop. Do any of the 24 homes on the lake have lawns that get fertilized and then drain into it? Are they on individual septic systems?

I see you are in Illinois. If you are looking for lake management/fish supply, the Herman Brothers have an excellent reputation here.

Is there any chance that someone disposed of something in the pond? It's certainly a far-fetched thought, but to think that the water went 100% bad not so probable with the aeration you have.

We had a careless crop duster spray our pasture, waterways, and pond. I called the State and they sent someone out to take samples for testing. Certain chemicals are regulated and can't be used in watersheds. If a professional lawn service messed up and caused the kill they could be covered with insurance. You won't get those fish back but you might get them replaced. And IF that's what happened there would probably be less chances of it happening again if a claim was filed.

Theo, i'm not sure if any of the lawns get fertilized. THat was one thing i was going to bring up at the next mtg. But is likely for sure

As far as someone dumping something in the lake, heck you never know with people lol. That was one thing i thought of too.

Update: More fish are floating today, temps did rise in the 90s today.
Thanks for all your replies. We are reaching out to businesses to see what they charge to come do the fish removal. I"m just wore out and others around the lake are in their late 70s/80s. Just not mobile and also its hot out now.

Fish harvest is an integral part of pond management. What likely happened is this:

The pond reached carrying capacity over the past few years. Adding more fish without removing some pushed it to the brink. A hot day with the extra nutrients (goose poop) fed a bigger than normal phytoplanktom bloom.

What was the water visibility right before the fish kill?

The excess phytoplankton bloom stopped producing O2 at night and started consuming it. The fish got the short end of the stick and suffocated during the night.

Does the aeration system run 24/7? With the aeration system running 24 hours a day, how many water "turns" happen in 24 hours?

Case in point, a local HOA pond (18 acres) didn't have enough $$ to aerate the whole thing. So, they purchased a system for half of the pond and we installed it. It ran 24/7 and one hot night they had a fish kill - but only on the side of the lake that didn't have the aeration system.

Since the fish kills are a regular thing, you need to break the cycle - don't keep doing the same thing year after year.

1) You HAVE TO harvest fish or mother nature will do it for you as you found out.

2) Make the geese unwelcome. There is a product called flight control that gets sprayed on the grass and it upsets their belly, so they move on to better tasting pastures. There is also a LED light product called Away With Geese that is a solar powered, battery backup that disrupts their sleep. They move on after a bit. ANYTHING to reduce the nutrient loading in the pond will help minimize a fish kill in the future.