Pond Boss Forums Thread Like Summary - 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.

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.

Our Border Collie loves chasing geese. She also chases buzzards and crows, but her favorite is chasing the GBH - it flies slower than she runs, and usually just tries flying to our other pond!

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.

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

Thats quite a load of floaters for sure.

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.

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.

Regarding geese, they prefer areas where the grass is cut regularly, like yards next to a pond/lake, golf course, etc.

Letting the grass grow taller, while not desirable to the human, greatly reduces the presence of geese. My neighbor who has a commercial building by a year-round stream has experienced this, and I have also seen this at my property.

I guess the geese are not as comfortable in the high grass as they are more susceptible to predators.

I lost all my fish in a 5 acre pond some years back. It was weather related as we went from high heat to cool weather and the pond turned over. Fish were gasping for air. Had no aeration.
On my pond I have now I run 4 aerators

There may be both state and federal regulations regarding "discouraging" geese. Make sure you know those!

As Sunil says, they love mowed grass beside ponds. At my father's golf club the geese are a constant nuisance for just that reason. The grounds crew rides with an Australian Shepard in their 4-wheeler. They just stop the vehicle and give the dog a command and he will quickly chase a few hundred geese off of the fairway. Some fly away, but some just head into the adjacent pond. However, if they get chased several times a day, the geese are just smart enough to move on and find some more "peaceful" lodgings.

P.S. The dog thinks he is a champion goose "herder" and is quite proud of his hard work!