Several days ago we had a few dead fish and since then there are now 15-25 per day. A few are partially eaten or chunks missing. Nearly all have red places and some red punctures or splotches as can be seen in the photos. Any idea what is happening to them? We do not see any birds other than a Great Blue Heron that is on the edge of the 1/2 ac pond sometimes. Do not see kingfishers or other birds other than the occasional goose and ducks. There have always been a few turtles and occasionally a snake swimming around. The pond is 2.5 years old and has been stocked with the bluegill and bass since month 3. Any help will be greatly appreciated.[img]https://www.dropbox.com/s/tz0aef5qywt0hv7/20220508_123509.jpg?dl=0[/img]

Tom, welcome to Pond Boss.

This should be one of the pictures. I'm not sure if there were others in that link:

Most of the puncture wounds by herons, that I have seen, have been on the top sides of the fish in general, so I'm doubting that those are wounds from a heron.

Let's see what others have to say...

Here are photos from those I picked up this morning. Thanks for your ideas.

Agree Sunil. But, only a long bill bird would do something like that.

Tom, I would put out some game cameras.

I was just speaking with esshup/Scott on a unrelated topic, and he thought this would be more like a bacterial issue coupled with stress on the fish from perhaps water quality, as opposed to bird punctures.

The half fish would be due to being eaten by snapping turtles after death, IMO.

Water test would be a good idea - see if any stressors there.

At 2 Yrs. old the pond is reaching carrying capacity which might be a factor.

What else is going on at the pond, weather, spawn, liming, chemicals etc..?

My experience as well. And multiple puncture wounds are exceedingly rare with herons at my place.

@Ewest - Thank you for the good points. I hope the info below is responsive.

Water Test using HACH AquaCheck 5-in-1 test strips:
ph 6.8, Hardness 50 ppm; Total Alkalinity 40 ppm

What else is going on at the pond:
Q: weather? A: Typical for 13 miles from the Gulf Coast. Warming up with nights in the low 60's and days in the high 80's and humid...of course.
Q: spawn? A: Most of the dead fish have been female and some are quite fat and appear, to this novice, as being full of eggs
Q: liming, chemicals etc.? A: I last limed the pond on 3/5/2021. There have been no fertilizing or herbicides used around the pond. If you go to the link below and look around you will note my neighbor's property is only about 20 ft from the pond's edge. But, he is one of those ultra organic guys that let the bugs eat his garden. So, nothing has washed in from him.

Go to https://sundownfarms.com/category/pond/ for my journal on what has happened in and around the pond.

Thank you so much for helping. I have fed those rascals for two years.

Most of the fish above are male CNBG. They are all big adult fish.
At your location there would most likely have been an April and maybe a March spawn. Have you caught any live CNBG during this time period and if so, how did they look? Did they appear to have red (raw) fins and tails?

I did not catch any during that time. I will catch some today and report back.

My hunch is in agreement with Sunil's suggestion. I recall another member from Alabama having a similar issue. Some of his BG were >12 inches. The remedy suggested was terramycin treated feed.

Something may be amiss with water quality that is weakening their ability to fight infection. Or perhaps the environment has too much bacteria to successfully fight it. Though probably more to do with water condition weakening the older fish.

I haven't posted in forever. I am not sure if I am the one in Alabama you are referring to or not, but I had a large winter fish kill. All male bluegill. Auburn University did a study on mine and said it was an opportunistic bacterial infection. I was told to treat the fish with an antibiotic. Seems like I used penicillin. It was fairly cold so fish didn't feed well. I mixed the medicine with a bottle of Caro syrup. Poured it over a 50lb bag of feed and mixed in a wheel barrow. I didn't lose them all, but I did lose the largest class of male bluegill. It was sickening since a trophy BG pond was my goal. Since then everything is doing good. My original stocked LMB are pellet trained. I have 15 or so of them that take the large pellets. They are are 8-9 lbs now. Pretty awesome to watch them.