I know this can be any number of things, but wanted to see what pb suggested here. A few weeks ago South Texas where I am got the coldest temperatures and longest freeze we've seen in 100 years.

No big deal really my 3/4 acre pond seemed fine after the fact. Normally this is very much spring time for me though so 2 weeks after the freeze (last week) I went ahead and turned my feeders back on. It was 84 degrees outside yesterday and we will be nearing 90 next week.

Well I showed up this weekend and I have about 15 BG dead. All big and all very healthy looking. This is only my ponds 2nd year in existence and I haven't taken any fish out of it yet.

I'm thinking possibly the weather just shocked their systems and feeding was a bad idea. I'm going to check the water today and make sure my numbers are not out of whack. I don't have any dead bass and there are TONS of minnows still. I have quite a few BG in the pond so not all of them are dying.

I did notice after the feeding yesterday afternoon though much of the feed had gone untouched.


Should I cut the feeder off for a few more weeks? Any other Texans experience anything like this after the winter storm?

15 big BG dead - did they look freshly dead, or maybe dead for a while and just floated up?

Do you know what your water temp was when you restarted feeding?

Some seemed pretty fresh others stank pretty bad like they had been floating for a while. I'm not sure the water temp, but I still have some clarity issues I'm working out so the surface temp and the deeper temps are probably considerably different.

I've cut the food off for now to see if it keeps happening. I also have an aerator and the pond is well fed which also aerates the water so I really don't think it's an oxygen issue. It's weird though because it's just bigger BG. I don't even think the bass at their current age could even eat any of these they are so big.

Any chance the pond "turned over" due to the bitter cold and caused a severe low oxygen event?

This shouldn't be bad on only a 2 year-old pond? If it did occur, would it impact the LMB more than the BG?

Would feed on the bottom that was not consumed during late fall/winter contribute to an anoxic event?

Did you aerate the pond throughout the winter?

Not all dead fish float. You have an unknown situation.

i did aerate all throughout the winter, but we only got 1 week of winter honestly. That being said the aeration is solar powered so good chance those brutal cold days that chained together the aeration stopped. I did stop my water well for that period as well.

possibly that's what happened though.

Hopefully, your LMB fared well and your BG population will be able to quickly replenish their numbers back to the level you like.

Good luck!

So I checked the water levels and the only thing that is off is Ammonia which is .25ppm. I've never seen that above 0. I'm assuming the dead fish is why that number is there, but perhaps that's what is killing them?

That is higher than normal but not in the toxic levels. What's the pH and water temp? Ammonia toxicity is dependent on that too.

Was any of the fish food moldy?

PH was 8. Water temp in upper 50s yesterday afternoon. No moldy fish food that I can see. I've cut feeding for the time being until this gets under control. There are more fish coming up and some of them have algae on them so I'm guessing they were not floating and been dead longer than I realize which is leading me to believe that I had an oxygen issue with the cold weather. I don't have much in the way of vegetation actually in the pond water, but what vegetation there is it looks pretty dead from the cold snap.

Edit: Just went to check on the pond again and have a ton more fish. Lots that are definitely stinky like they've been dead for a while. A blue heron even pulled one out and put it on my floating "feed" dock and didn't eat it.

Guessing oxygen event. It's still very odd that I'm only seeing bluegill though. Still not a single bass. Though they may be about to start popping up.

Any way to test the oxygen in a pond? Also is it possible I was just way over capacity? When my feeder goes off I always sort of felt like it was an absurd amount of fish. I somehow had bluegill before I even stocked I guess because birds, so it's possible my BG population was already established.

So many possibilities. I'm trying to decide if I go ahead and stock with young BG for the bass, but I hate to do that just to have them die.

Could very well have been an O2 crash. All it takes is 2" snow and 2" cloudy ice to stop the majority if not all sunlight from getting to the water. Phytoplankton produces a lot of O2 during the winter when the plants aren't growing, but if there is no sunlight they utilize O2.

That's why having a large amount of water in the pond in regards to the biochemical demand and also having 10% of the surface area open to the air is the ticket for minimizing winterkill when ponds are iced over and then snowed upon. I've seen a winterkill in less than 2 weeks in a pond without winter aeration and not a lot of water (5' depth max).

More than likely, these BG are CNBG, I'm guessing..
I'm highly suspicious that a fast "rate of change" is more than likely the culprit here. The rate of temperature change is more of a factor than the actual temp.
I keyed on one other item you mentioned.. "algae on the fish"... are you sure this isn't fungus that has taken on an "algal" color?
I'm personally leaning in a direction of a stress kill more than anything else. Not saying low DO wasn't an issue, maybe a contributing factor but you went through, as you said, "the worst conditions in 100 years"..

My thoughts as well. CNBG will eat aggressively in 40 degree water, but even with warmer water, they will shut down if there's a rapid water temp drop. I haven't found any post ice over CNBG morts, but there are some larger ones that have fungus on them. I haven't seen the fungus on smaller CNBG.

Maybe a good idea to throw some salt in the water to help with potential fungus on the fish?

So I was wrong it was mostly just dirt and some loose algae from the fish basically getting stuck in some of my water plants along the edge that have algae on them. It washed right off though it's not any type of fungus.

here is a picture of one of them: https://ibb.co/grZnwhF


Water temps definitely fell rapidly. We were in the 70s and 80s already outside temp and then out of nowhere had a 3 day freeze that we hadn't seen in 100 years. Then a week later we were back into the 80s.

Definitely seems like it turned over, but maybe the stress screwed them up. It's just odd I didn't see this last week and I turned the feeder on and this week they start popping up. I'm guessing they were just stuck in the depths.

Not a bluegill. Tilapia.

Holy crap how the hell did I get Tilapia in my pond!!!!

That might actually explain it right? they are no good with cold water if I recall? Possibly this was a blessing in disguise I don't think I want Tilapia in my pond.

Edit: on a different note would Tilapia be a cause of turbidity in my water by chance?

In large #s yes they can cause turbidity.

Theoretically, all of the tilapia may have died in that cold snap!!

So glad you posted a picture link!

Quite a few things starting to click here. I had been confused about this for a while when I feed the fish many of them did not look like bluegill to me but I've had murky water so I thought maybe the weird colors is lack of sunlight.

I've tried gypsum, and alum both. Neither did anything to solve my problem. I've pulled 40 or so out of the pond so far, but no telling how many the hawks have snatched up. Plus I expect there to be quite a few more when i go back. I'm headed back up there mid week to keep pulling them out so that I don't create a worse situation.

Now I'm not even sure how my actual stocked BG situation is as I haven't really seen them. I've caught 2 bass that were perfectly healthy and appropriate size in October. I assume they don't mind eating tilapia offspring.

I have no idea how I got Tilapia though so I'm guessing this may end up continuing to be a problem I need to deal with somehow. Guessing my resident blue heron is to blame. sighhh..

Bass love eating Tilapia. Now if they all croaked, I'll bet you will have a FA problem once the water warms back up.

I've always thought so, and have stocked accordingly. But not sure there's a lot of empirical evidence to back it up. Bob Lusk has said that BG yoy survival rates go up when TP are present, which is a plus, but that doesn't mean the bass are eating TP. Wish there were some research studies on the question!

I think bass all four species, Flordia, Kentucky, Smallmouth, and HSB will eat everything they can get in their mouth when they are actively feeding. And when reproducing lmb are guarding their nest or fry there is a window of time when they will eat things that gets in their way to protect the nest or fry.

Yeah after researching about Tilapia it doesn't seem like a horrible fish for the bass and honestly we never get freezes down here so it wouldn't be so bad. Now that I'm thinking back to all the times I watched the feeder go off and them absolutely destroy the fish feed I'm thinking I was just way over populated with Tilapia. It's not a large pond so my bass carrying capacity is not massive.

My main issue with this pond has been water turbidity that I'm having a real hard time solving so I'm going to see how it does over the coming weeks and if I start to see better clarity I think my culprit was the over populated Tilapia.

My new problem is trying to determine if I have enough BG to sustain the bass. I'm thinking about just stocking a bunch more and seeing how they do. I can feed the heck out of them anyway I have a 300lb feeder that I use.

Thanks for the help all.

Speaking of tilapia, will they be available for stocking this year? I've heard threadfin shad will not due to the freeze, and tilapia are at least as vulnerable to cold.

Yep, I'm gonna get with Snipe, and try to do the salt bath deal. I've got to get the cages back in the water, so I can hold the CNBG and see if they improve.

Not hard scientific data, but if the LMB body condition stays the same, and there are more BG surviving, then what are the LMB eating if not the TP?

Here is a list of Largemouth bass food items from FishBase (scientific).
I can't believe anyone thought a LMB would not eat tilapia (or anything else it can get in its mouth).


Food I Food II Food III Food name Country Predator Stage
nekton finfish bony fish Acrocheilus alutaceus USA juv./adults
zoobenthos insects insects Anisops sp. Kenya juv./adults
zoobenthos insects insects Anisoptera nymphs Kenya juv./adults
others others n.a./others Anisopteran adults Japan adults
zoobenthos benth. crust. shrimps/prawns Atyaephyra desmaresti Spain adults
nekton finfish bony fish Barbus paludinosus Kenya juv./adults
nekton finfish bony fish Barbus spp. Zimbabwe juv./adults
nekton finfish bony fish Carassius gibelio Japan recruits/juv.
zoobenthos benth. crust. shrimps/prawns Caridina denticulata Japan juv./adults
nekton finfish bony fish Catostomidae USA juv./adults
nekton finfish bony fish Centrarchidae USA adults
nekton finfish bony fish Centrarchidae USA recruits/juv.
nekton finfish bony fish Centrarchus macropterus USA juv./adults
zoobenthos insects insects Chaoborus pupa Kenya juv./adults
zoobenthos insects insects Chironomid larvae Kenya juv./adults
zoobenthos insects insects Chironomid pupa Kenya juv./adults
nekton finfish bony fish Clupeonella abrau Russia adults
nekton finfish bony fish Cottidae USA juv./adults
zoobenthos insects insects Culicid pupa Kenya juv./adults
nekton finfish bony fish Cyprinidae USA juv./adults
nekton finfish bony fish Cyprinodontidae USA juv./adults
nekton finfish bony fish Cyprinodontidae USA recruits/juv.
nekton finfish bony fish Cyprinus carpio carpio USA juv./adults
zooplankton plank. crust. cladocerans Diaphanosoma brachyurum Japan recruits/juv.
nekton finfish bony fish Dorosoma cepedianum USA juv./adults
nekton finfish bony fish Dorosoma petenense USA juv./adults
nekton finfish bony fish Dorosoma spp. USA juv./adults
zoobenthos benth. crust. amphipods Echinogrammus sp. Spain juv./adults
zoobenthos insects insects Ephemeroptera Spain recruits/juv.
nekton finfish bony fish Esox spp. USA juv./adults
nekton finfish bony fish Gambusia affinis USA juv./adults
zooplankton fish (early stages) fish eggs/larvae Gambusia affinis USA juv./adults
nekton finfish bony fish Gambusia holbrooki Spain recruits/juv.
nekton finfish bony fish Gasterosteidae USA juv./adults
nekton finfish bony fish Gymnogobius urotaenia Japan recruits/juv.
nekton finfish bony fish Ictaluridae USA adults
nekton finfish bony fish Ictaluridae USA juv./adults
nekton finfish bony fish Ictalurus spp. USA juv./adults
zooplankton fish (early stages) fish eggs/larvae Ictalurus spp. USA juv./adults
nekton finfish bony fish Labidesthes sicculus USA juv./adults
nekton finfish bony fish Lepomis cyanellus USA juv./adults
nekton finfish bony fish Lepomis macrochirus Japan juv./adults
nekton finfish bony fish Lepomis spp. USA juv./adults
zoobenthos insects insects Micronecta scutellaris Kenya juv./adults
nekton finfish bony fish Micropterus dolomieu USA juv./adults
nekton finfish bony fish Micropterus salmoides France adults
zoobenthos insects insects midge larvae USA Larvae
nekton finfish bony fish Mugil cephalus Japan juv./adults
nekton finfish bony fish Mylocheilus caurinus USA juv./adults
plants other plants benthic algae/weeds Najas pectinata Kenya juv./adults
others others n.a./others Nematocera adults Spain recruits/juv.
zoobenthos insects insects Nematocera exuviae Spain recruits/juv.
zoobenthos insects insects Nematocera larvae and pupae Spain recruits/juv.
nekton finfish bony fish Notemigonus crysoleucas USA juv./adults
zoobenthos worms n.a./other annelids Oligochaeta USA juv./adults
nekton finfish bony fish Oncorhynchus mykiss USA juv./adults
nekton finfish bony fish Oncorhynchus tshawytscha USA juv./adults
zoobenthos benth. crust. shrimps/prawns Palaemon paucidens Japan adults
nekton finfish bony fish Percidae USA adults
nekton finfish bony fish Percidae USA recruits/juv.
nekton finfish bony fish Percopsidae USA juv./adults
nekton finfish n.a./other finfish Petromyzonidae USA juv./adults
nekton finfish bony fish Poecilia reticulata Kenya juv./adults
nekton finfish bony fish Pomoxis nigromaculatus USA juv./adults
zoobenthos benth. crust. lobsters Procambarus clarkii Kenya juv./adults
zoobenthos benth. crust. n.a./other benth. crustaceans Procambarus clarkii Kenya juv./adults
nekton finfish bony fish Pseudorasbora parva Japan recruits/juv.
nekton finfish bony fish Ptychocheilus oregonensis USA juv./adults
nekton finfish bony fish Rhinogobius giurinus Japan juv./adults
nekton finfish bony fish Richardsonius balteatus USA juv./adults
nekton finfish bony fish Rutilus rutilus Spain recruits/juv.
nekton finfish bony fish Rutilus rutilus Spain juv./adults
nekton finfish bony fish Salaria fluviatilis Spain recruits/juv.
nekton finfish bony fish Salmonidae USA juv./adults
plants other plants benthic algae/weeds Salvinia molesta Kenya juv./adults
zooplankton plank. crust. cladocerans Sida crystallina Japan recruits/juv.
nekton finfish bony fish Sunfish USA juv./adults
nekton finfish bony fish Tilapia zillii Kenya juv./adults
zoobenthos insects insects Trichoptera larva Kenya juv./adults
nekton finfish bony fish Tridentiger obscurus Japan juv./adults
nekton finfish n.a./other finfish unidentified Spain juv./adults
others birds shore birds unidentified France juv./adults
others mammals n.a./other mammals unidentified France juv./adults
zoobenthos benth. crust. benth. copepods unidentified Kenya juv./adults
zoobenthos benth. crust. n.a./other benth. crustaceans unidentified USA juv./adults
zoobenthos benth. crust. ostracods unidentified Kenya juv./adults
zooplankton other plank. invertebrates n.a./other plank. Invertebrates unidentified (not available) recruits/juv.
zoobenthos other benth. invertebrates n.a./other benth. invertebrates unidentified Arachnida Kenya juv./adults
zooplankton plank. crust. cladocerans unidentified cladocera USA Larvae
zooplankton plank. crust. plank. copepods unidentified copepoda USA Larvae
zooplankton plank. crust. plank. copepods unidentified copepods Spain juv./adults
zoobenthos benth. crust. n.a./other benth. crustaceans unidentified crayfish USA adults
others others n.a./others unidentified Diptera Kenya juv./adults
zoobenthos mollusks gastropods unidentified gastropod Kenya juv./adults
others herps toads/frogs Xenopus adult Kenya adults
others herps toads/frogs Xenopus tadpole Kenya adults
others others n.a./others Zygopteran adults Japan adults
zoobenthos insects insects Zygopteran nymphs Japan juv./adults

Good info. My only reservations concern research reports, published in Pond Boss, that tilapia were rarely found in LMB stomachs.

ewest,

Thanks for that lengthy list of food items.

However, I did not see "green screwdriver" - as Jim Wetzel has reported. Obviously, that is only a partial list of what LMB will eat.

+ 1 or an AFLAC duck - lots of reports of plastic worms/craws/creature baits however.