My father in law's pond seems to be having issues. Last night he saw hybrid blue gill gasping for air. This morning there are 4 dead and many still gasping for air. He has his aerators on 24 hours a day for the past 2 days, 4 diffusers in his one acre pond. Prior to this he had the aerators on a time running mostly at night. It is in Worden, IL and has been hot 90 degrees plus.

He hasn't sprayed his pond, doesn't have an abundance of algae, nothing added to the pond this year other than feeding his fish...Which he does by hand.

Any suggestions that I can pass on to him?

Tagged for answers.

My $ says water temp is just high enough so dissolved o2 is low...but, if aeration is in use at night, seems like the cooler, deeper water would have available o2.
How deep is the pond?

Mike,
Since the fish are piping, you know O2 is low.

Before we can help eliminate the problem, we need more information.

Hows the biomass? Too many fish can cause this problem. Too much vegetation can make it worse.

How deep is the pond? Do you know the water temp? Have you checked the chemistry?

All these things and more can contribute to your problem. The quickest fix is to reduce the fish load. This will give you time to figure out the rest of your problems.

The pond is 12' - 14' at the dam, 4' - 8' from the other end sloping to the dam. April 2016 we stocked 250 RES, saw probably 50 of those die same day. 450 HBG different sizes, 3" - 5" and 5" - 7". 150 CC and 75 albino catfish. I don't know the water temp or chemistry.

How old is the pond? Have you had fish in since the beginning? Other species?

Old pond that was killed off 3 years ago and then stocked in April 2016. Water will be tested tomorrow, hopefully leaving the aerators on 24/7 will bring it back.

Unfortunately, if this heat continues in the Midwest, this won't be the last post of a kill off. I'm right in the middle of one, 1 acre pond with 3 diffusors...didn't help. It was sprayed several days ago. My Kasco surface aerator is burned out, that might have saved them. Nothing I can do now. I would advise anyone in the heat zone not to spray right now, aeration or not; half treatment or not.

I bet running aerators in the daytime will heat the water even in the deeper cool spots. Tough call.
I'm learning from each of these fish kill posts. Thank you for posting it.

That's what I was worried about, but have been told both ways. My father-in-law was told to run them only at night.

I have had a fish kill in my pond plus witnessed one in a friends pond - no fun at all. Lost huge catfish and bass.

First time it happened I thought the same thing - some type of poison got into my pond. However it turns out that the pond turned over and lost oxygen -

To my knowledge an aerator is the solution - good luck to you

He needs to get water temps, but my guess it is a combination of biomass and water temp.

I would be removing as many of the CC as I could asap, and run aerator only at night.

Anytime there is a DO problem and fish are at the surface gasping for air you have an emergency situation. You need to create an O2 sanctuary asap. Any type of tool that will churn up the surface water should be used. You can move diffusors shallow 2 ft , use a boat motor/prop to churn water , or other method. You can figure out temp and causal matters later but get some DO into the surface waters. Fish can sense and move toward areas with improved DO status. Breathing comes first !

See this

https://srac.tamu.edu/serveFactSheet/292

Remove at least half the CC!

So other than the heat, the catfish are causing problems?

I can't speak to your specific problem, but here's what I've learned.

When biological oxygen demand exceeds supply, a fish kill occurs. You can aerate to increase oxygen supply and/or remove biomass to reduce demand. Too many fish = too much demand.

Catfish can also increase turbidity, decreasing light penetration and reducing oxygen produced by photosynthesis.

The CC can take up a lot, or most of the biomass, if large. I had the same problem last year. One morning they didn't come to feed, and were hanging around the bank. I netted out a few of the stressed ones, dressed them before they could die in the pond. I ran a pump to circulate the water, then immediately started catching out the CC (2 to 5 lbs each). I never had another problem. Last winter the otter attacks reduced the biomass even more. We ate CC last summer until they became "just another meat".

when I lost my pond it had nothing to do with the number of fish - it was well balanced

We had a very cool night followed by a hot day and the lake turned over - depleted the oxygen and fish died

Tim your event is a common type fish kill and happens way to often.

I didn’t want to start a new thread about fish kills, so I’m just jumping in on this thread. I was at my pond yesterday. We’ve had a lot of days in the 90s, and I’m sure a lot more are coming. I don’t aerate, so not much I can do about it, but my water temps are climbing. I get a temp off the dock about 15’ from shore, and a foot deep. It was 87 degrees. Warmer than in the past at this time of year, that’s for sure. Diving in off the dock, it’s still pretty cool once you get down about 18”. My water clarity is about 12”.
What temps should I be looking out for that may signal impending problems? I could take the jon boat down in the evening and run the motor for a while to stir things up. Would that be advisable?
Thx
Jeff

I had to use my outboard last week due to 99 degree surface temps.


I was advised to try to only stir the top 2/3 of the pond. I don't have aeration yet either. Pulling up that dead water from the bottom would be just as detrimental to your fish.

If aeration has been in place, I'm leaning toward either an overpopulation issue, or possibly the diffuser isn't moving enough water to get a complete turnover just running it at night....or a combination of both.

How long has it been since the diffusers were cleaned or replaced?

No aeration at all. My pond is too far from our barn to run lines, either electric or air. Plus I’d have to run lines up and down through a big rocky ravine and 90% woods. Just not a viable option. I’ve looked at solar, but the $1,000 systems aren’t really going to move the amount of air I need or lack durability. Or, the $7,000 systems are just priced too high. So, I’m hoping for the best. Cutting back on feed. Hoping that will slow down the growth of total biomass.

I am also curious about the temps/turbidity conditions that we should start worrying about O2 depletion.

I have been seeing 85 degrees - 18" below the surface, out 25 feet from shore and 75 degrees at the bottom (7 foot deep - 25 feet from shore). My secchi readings have gone from 3 foot to 2 feet in the last few days also.

I'm only a couple weeks away from starting the aeration system, however, and my fish are acting just fine.

Setterguy, I've noticed with my pond that even tho the surface temp is crazy high (94 yesterday), as long as there is cooler water under it with O2, they'll be ok. 87 isn't too bad. But if you have an outboard motor, I'd keep it close by.

My fish seem to be doing fine even tho it's hot on top. When I stirred the pond last week, every bedding fish left and everything quit feeding. Yesterday there were 200 staged on the bank waiting for dinner.

Mike W., Are you taking the surface temps at the very surface (within a few inches?)?

Wow, how do you put up with that kind of heat that gets water temps above 90? By June! Sure we deal with 6 months of winter, but that heat and humidity would get old really fast.

My water temp is sitting at a refreshing 71, and pretty much the entire column is the same temperature straight to the bottom thanks to cold nights and wind. The perch love it, and so does the curly-leafed pond weed which is too rambunctious this year as it loves cool water.