Pond Expert Needed

[Rich/WIS]

Have a one acre pond on my property, spring and rain water fed. Every spring I add Cutrine and a pond die to control algae, was done before I bought the place and by me for the last five years. Never had any issues til this week. Went to visit my son in NC and when I left Friday AM all was well. Came back last night and found three dead bass 11-13 inches and a 30 inch carp floating in the pond. This AM found a 9 inch bass and a 2 inch panfish. None of the fish showed any obvious injury and given the size of the carp and bass don't think it is the Heron that sometimes visits.

Any one with experience with something like this?

[Ghost23]

Maybe a ph swing?

[waksupi]

I've seen winter kill make floaters. Call your county extension agent and ask him about it.

[HWooldridge]

I've had it happen during long periods of hot weather, followed by a rain shower. The water does an inversion and the O2 levels get messed up. I had one happen a few years ago and lost hundreds of fish - way more than I thought were even in the pond. With that said, we haven't entered the summer months, so another possibility is that you got some bad runoff from upstream. Maybe a neighbor sprayed something he shouldn't have...

[cwtebay]

Not pretending to be pond expert, but I have several. Generally it's an oxygen dissolution problem. That can be due to several causes such as overstocking, pH imbalances, vegetation overgrowth / undergrowth, weather conditions....
I thought I was pretty good at farming fish for a couple of years in a small pond like yours until we had several days of sustained wind from an unusual direction. Lost around 80%.

Sent from my Pixel 5 using Tapatalk

[racepres]

Besides Winter kill, the thing that has devastated our Pond(s) Fish, was the underwater vegetation dying.. maybe what caused the winter kill also. my Fisheries Biologist, friend, says snow cover blocks sunlight which lets Vegetation die...and the fish depend on vegetation for Oxygen... I suspect spray or Nitrogen, other chemical run-off can kill vegetation also..
BTW, I asked him if they didn't get oxygen from the underwater springs... He Says...there is Little to No Oxygen in ground water...so...No Help

[Rich/WIS]

Any of the above could cause issues but would expect it affect all the fish. There is no run-off other than the grassy slope in my yard and the neighbor and she doesn't apply chemicals of any kind. Winter kill is unlikely, only had at most two days of ice cover a few months ago. There is plenty of vegetation on the sides and bottom. The carp was old based on its size and two years ago had another one about the same size die. My daughter teaches for the Univ of WI and she asked around the biology department at the time and was told likely cause was old age, "fish don't live forever". What puzzles me is the bass are predators and there is abundant food with the panfish reproducing in the pond. Will keep an eye on it and see what develops.

As a side note I tossed the three dead bass I found last night onto the grass. This AM one was gone and crows and black buzzard were enjoying the buffet. Tossed them into the woods and drug the carp to an open area on the far side of the pond to see how long it will take the birds to find it.

[HWooldridge]

They might also have parasites. Did you cut open the carcasses and/or look around the gills?

[racepres]

Any of the above could cause issues but would expect it affect all the fish. There is no run-off other than the grassy slope in my yard and the neighbor and she doesn't apply chemicals of any kind. Winter kill is unlikely, only had at most two days of ice cover a few months ago. There is plenty of vegetation on the sides and bottom. The carp was old based on its size and two years ago had another one about the same size die. My daughter teaches for the Univ of WI and she asked around the biology department at the time and was told likely cause was old age, "fish don't live forever". What puzzles me is the bass are predators and there is abundant food with the panfish reproducing in the pond. Will keep an eye on it and see what develops.

As a side note I tossed the three dead bass I found last night onto the grass. This AM one was gone and crows and black buzzard were enjoying the buffet. Tossed them into the woods and drug the carp to an open area on the far side of the pond to see how long it will take the birds to find it.drug the carp to an open area on the far side of the pond to see how long it will take the birds to find it

We have Eagles, and Cormorants, and some little Hawks here... Nothing lasts in the Open...a dead skunk is something they Fight Over

[Rich/WIS]

The bass I found this AM was fresh but didn't think to cut it open. Heck, wouldn't know what I was looking for. From what I could see of the gills they looked fine.

By this afternoon the black buzzards were enjoying a carp dinner on me.

[Plate plinker]

Maybe you need an air bubbler. I see small ponds around here that have them. It also keep the surface clean from my observations.

[MrWolf]

Maybe you need an air bubbler. I see small ponds around here that have them. It also keep the surface clean from my observations.

My thought also. Probably one of the easiest solutions to implement.

[RickinTN]

My two neighbors with ponds have fountains to oxygenate the water. Similar to the methods mentioned above I guess?
Good Luck,
Rick

[racepres]

I vote for a Bubbler, or stirring device (windmill) to Aerate..All of our Fish never died...only some.. why??? IDK that maybe the strongest survived??? Oxygenating stopped the dye-off!!!

[Rich/WIS]

Found another floater this AM but cause of death was obvious, the last 1/3 of what had been a 9-10 inch bass was bitten off! Checked the gills and they looked healthy. Don't have any big fish in the pond or thought I didn't. Now wondering what the hell is in the pond.

[HWooldridge]

Found another floater this AM but cause of death was obvious, the last 1/3 of what had been a 9-10 inch bass was bitten off! Checked the gills and they looked healthy. Don't have any big fish in the pond or thought I didn't. Now wondering what the hell is in the pond.

Do y'all have otters there?

[racepres]

Do y'all have otters there?

Probably Not...Or there would be Once Bitten carcasses Everywhere!!!In winter it looks like someone was slaughtering hogs on the Ice!!!
Pike love to take Big Bites!!! But, I never heard of anyone seeing them where You are at..

[10x]

High organic matter and high nutrient levels in a pond can cause oxygen depletion. An Algae bloom can happen in 2 to 3 days or faster. When plants die, they take up oxygen when they decompose.
Well aerated water will have between 9 to 11 Parts per million O2. Wind can stir up organics on the bottom of a shallow pond and the 02 levels can deplete to almost zero very quickly.
Also a blue green algae bloom can be toxic to fish and other aquatic life.

https://www.nature.com/articles/s41579-018-0040-1

[Bmi48219]

Ducks & geese can unwittingly transport fish eggs (pike eggs too) in their feathers. We bought a property that was overrun with pygmy warmouth bass the original owner had never introduced to the pond.
One pike can decimate the population of a pond in no time flat. Pike have an easier time eating small bass shaped fish than flat crappie or bluegill types.

I’d guess low oxygen levels was your problem, especially if your die-off is mostly larger fish. As others have noted, controlling aquatic vegetation can reduce oxygen levels. Most products recommend treating 20-30% of pond area at a time to try to avoid that. I had good luck with chelated copper sulphate, by dissolving the crystals in hot water and spraying the mixture under some pressure to penetrate clumps of algae and vegetation. Only treated 1/4 of the pond at a time. Never had much success with the blue dye in a spring-fed pond.
Early in our pond-owning experience I attended a MSU presentation about managing & maintaining private ponds. The one scientist said no matter how well managed, the ecosystem of most small ponds is very fragile and failures must be expected. Also that successfully controlling aquatic vegetation and predator species creates an ecological void, and Nature abhors a void.

[725]

Tend to agree with all the above. Instead of chemicals to treat the pond, have you ever thought of tossing a bail of barley straw in the pond? I bet that alone will solve your algae issue. (I wrap the bail or portion of a bail in netting to keep it together). Just let it float around. Next year, take it out and toss in another. Lots of ways to skin a cat.........

[GhostHawk]

As to your bitten off fish I would suspect a snapping turtle. That is classic behavior.