Hello,

I have an acre pond in NE indiana going into its second year. Its around 9-15' in deep end and 5-6' in shallow. This spring we added limestone around the pond to prevent erosion and I have grass planted with straw mats covering which was put in about a week and a half ago. I have about 250 YP of all classes. Every day for the past 4-5 days I have found at least one yellow perch floating on the edge but usually a couple (14 total now out of what I would estimate 275 in pond). The YP are from about 6" all the way to 13". The dead ones have been in 6-10" range. Minnows have died in bunches as well. The water is very muddy looking and some areas have a brown film. Originally I didn't have any water circulation. I noticed fish starting to die so threw in a water fountain I borrowed but hasn't done any good. Being a new pond there is no vegetation, just a little FA starting. I planted some duck potato and pickerel plant recently but it hasn't sprouted. Any ideas on how to stop the fish from dying?

Wonder if any bad chemicals in the straw mats?

What size are the ones dying?

Hi Bill,

6-10" and their gill covers have been flared out stiff.

Following along.. Hope you find out what’s causing this.

Sorry to hear, hopefully it stops as water clears etc.
Have you had some bad rain events? A pond that new with that few of fish shouldn't be having this issue in terms of carrying capacity etc... Have you tested the water?

It doesn't appear to be disease. I am thinking you are having low DO at night due to an large algal bloom. Did you fertilize? Are you feeding? Aeration?

Check the DO just before sunrise to determine if that is the issue

Hi Everyone,

Thanks for jumping in. It is heartbreaking seeing fish float and nerve racking not knowing why. We haven't had any hard rain in over a week now. I have attached a picture so you can see pond lay out. The fountain draws from about 1-4' down and is shooting water about 15' in the air. No diffusers yet. Some of the perch seem to also have a reddish tint but I'm not sure if that is part of their coloration or something else. Attached a few more photos. I will try to get a water test kit.

Also wanting to add I don't fertilize. I didn't put any on the grass for fear of it running into the pond. I do feed but only tried once this year and the fish were not eating it so I held off because I thought it may be contributing to whatever is going on. Looking back I don't have it in my original post but I have 20 SMB from 8"-16" and 10 HSB from 10"-12" and RES maybe around 100-200 1"-10". I haven't seen any of those floating other than just a few yoy RES.

Check akalinity, pH (Morning, afternoon, just after dark, 30 minutes prior to sunrise) total ammonia and nitrite if possible too.

14 fish out of ~275 is not minor, yet it doesn't overly concern me either since they did not all die at once... I don't know what you consider "bunches" of minnows either. Nor do we know how fast or when or how those died

Are the fish biting baited hooks? Do you see any visual signs of stress, like piping?

Your water looks overly fertile, and if you have a dense algae bloom, a couple cloudy days could really lower the dissolved oxygen levels...have you ever noticed several fish gulping air?

A great emergency aeration method for a smaller pond like yours would be to back a jon or smaller boat into the water and crank up the engine with the prop slightly cavitating, blasting bubbles and circulating water heavily...

Thanks for additional info! Update: I have collected 22 dead perch as of this afternoon. One of the bigger 9-10" redear floated up as well but looked like it had been dead a while. Saw a couple more perch out there in about the top foot of water swimming slow but none of the fish have been up gulping air. Bunches of minnows = hundreds dead on shore. Not enough to make a dent though as I have a lot of minnows still doing fine (photo of one school). My wife picked up a test kit so I can check levels tonight and report back. I have added new pics from the dead today.

do you have a well or a way to flush out water?

Ammonia - 0
Nitrate - 0
Nitrite - 0
Hardness - 300 "very hard
Alkalinity - between 120-180 "ideal"
PH - between 7.8 - 8.4 "alkaline"

I do have a well but it has sulfur water. Not sure if that is bad. To flush I think it would take more than what I could put through the well to the pond. Open to any suggestions though!

There is a good article on causes of fish kills in the current issue of Pond Boss Magazine (PBM) you might find helpful. If you do not subscribe, you can order a copy by calling the Pond Boss office.(800) 687-6075. I found it interesting that when other possible causes have been eliminated, the kills are often attributed to "algal toxicity".

Water quality looks great. I am guessing that you are having or had some dissolved oxygen issues prior to putting the fountain in. You clearly have an algal bloom by looking at the pictures. Look into installing an aeration system.

Hi Bill,

I do subscribe just haven't had a chance to read it yet. Read it this AM. Seems like any number of those issues is possible but its probably been a combination! I continue to see a few die a day but water visibility has been improving and the brown film seems to have gone away.Hopefully I only end up with a partial kill when its all said and done.

Thanks for confirming the water quality Acoursey! There for a few days in a row the wind died down and its was cloudy. That was prior to installing the fountain. I bet there was a die off then. Long term goal is bottom diffusers.

Think back over a month ago or even more. I have found that our perch do not float up after dieing for a good month. Most dead perch you don't see they go straight to the bottom. As the water gets mixed or warms up they will float up. What you are seeing could have been dead from the winter or ice over.

When I see that red at the base of the nose and fins its in larger fish that have been on the line for a long time fighting. I would bet those fish died of low O2.

I have no experience with fish that have died due to low DO but I have seen fish die and float at my place. When my Tp die due to cold water as the water temps drop, they have a fungus that grows on them or what I think is a fungus. And your pic of the Bg has the same look with the patch that looks like fungus to me. I have also had the same or similar type of fungus on some of the Golden shiners in my sediment pond when we get large rain events. I think in both cases it was brought on due to stress. So, I would look for something that is different from your norm. Pat, may be right when looking at the grass matts. Maybe a weed killer is in the matt and was washed into the pond during a rain event. In my sediment pond the water will turn color with all the clays being washed in and that causes stress, so any large rain event recently? I may not be much help here but I hope things improve for you soon. Dead and floating fish in large numbers can't be good.

Tracy, I had fungus issues on my BG last fall after a cold snap. Very worrisome, but haven't seen it so far this year.

Late to the game, but what about Golden Algae?

Total dead perch at 28 today. Uploading another photo of abnormal spot on perch. Maybe just because it was dead already or maybe this was on it while it was alive?

Here is the first live fish I have seen with "stuff" on it.

I am no expert, but that certainly looks like some sort of stress leading to disease. I would worry about something going on in the water, and get it tested to a higher degree (pesticides? metals?). It could still be fall-out from transportation, but for it to go on this long is doubtful.

It looks like fungus which often forms on fish which are under stress from a different cause.

On concern for me is that fish under DO stress generally do not take 2 weeks to form fungus and die. Could that fish have been dead a week with the fungus forming after death?

Any news on your fish kill? Curious if you have come up with a resolution.

Hi everyone,

Wanted to give an update. For about three to four weeks I was seeing fish die. From smb to res, yp, and a couple hsb. I would estimate I lost 1/3 to 1/2 the fish in my pond. Since then I have a fountain running, added some dye, have had more windy days, tree frogs went crazy and I have hundreds of thousands of tadpoles eating algae, added some tilapia, planted some more weeds and have been able to resume feeding. Caught a few healthy perch in the last couple days. From everyone I talked to it sounds like it may have been a perfect storm of issues. Bacteria/fungus, stressed fish from winter and lower DO. Algae bloom, and stressed fish from spawning all hit at the same time.

Hoping things are back on track. They say whatever doesn't kill you makes you stronger so at least the fish in there now have weathered the storm. Wouldn't wish those types of casualties on my worst enemies. Its hard to see fish floating that you have put so much work and love into.

Thanks to everyone that commented in this string!

Thanks for the update. I hate it when I read old threads and they just leave you hanging on what ever happened. Thanks for coming back and letting us know.