Today I noticed that I had about 20 dead fish today.
Last Friday we had a big rain.
Here are some pics of the first two I saw.
My son said that the larger fish weren't active at feeding yesterday.
I think I need to areate.
Carey
The big rain very possible caused a partial pond turnover. IF you don't aerate then that becomes even a more likely cause of a partial turnover.
Thanks for chiming in on this, Bill. I was kind of wondering if that could've been a possible explanation, but I wasn't sure if that would still happen this time of year and felt like it might be a misguided suggestion. Good to know that it was your suspicion. Is the possibility of the turnover because of the disparity between the temp of the rainwater - presumably cooler temp - versus what is likely now a fairly warm surface temp?
Since the pond is in SC it has had adequate time this spring to form a thermocline and some anoxic deep water. This is even more likely if the pond is old, surrounded by some trees and/or with relatively thick mucky sediments.
Makes total sense. Thank you for the thoughts on this, Bill.
Since the pond is in SC it has had adequate time this spring to form a thermocline and some anoxic deep water. This is even more likely if the pond is old, surrounded by some trees and/or with relatively thick mucky sediments.
The pond is about 4 years old.
Well no more fish have died, so I think it's safe to say it was a partial turnover
We have had two major rains that raised the pond level more than a foot (more than the rain that cause the kill) since the fish kill.
Why did the one rain cause a fish kill and these last two did't kill any fish?
Cold water (rain) sinks, turning over the rest of the pond, so if your water is stratified and then turns over, the layers which are void of Disolved O2 will move to the top (or closer to the top) and your fish will struggle and some die. Aeration combats this problem primarily by mixing the water column and allow all your water to off gas the bad stuff while adding needed O2. Nature naturally added some protection to the pond from the second turnover by naturally aerating the layers that move to the top adding O2 to the water column.
Why? Not definitative, but:
1) After the first fish kill, the biomass was reduced, requiring less O2.
2) After the first turn over, the water possibly wasn't as stratified as it was the first time, so the turnover "change" wasn't as great.
ok, i am officially freaking out!! Calling and ordering my stuff to build an aerator tomorrow!!!
Please dont let my pond turnover....Please dont let my pond turnover....Please dont let my pond turnover....Please dont let my pond turnover....Please dont let my pond turnover....Please dont let my pond turnover....Please dont let my pond turnover....
Pinetar,
Please read up on the right way to "start up" an aeration system. RC51 had a good write up about the time "on/off" per day when starting up an aeration system in an older pond so you don't do any more damage by starting another turnover. Patients is the operative word. Also, find Sue Cruz and PM her, she is a wealth of information about aeration systems and how to best set them up and start them up. For your pond right now this is the pound of cure, but it is going to bring you benefits from now on.
Why? Not definitative, but:
1) After the first fish kill, the biomass was reduced, requiring less O2.
2) After the first turn over, the water possibly wasn't as stratified as it was the first time, so the turnover "change" wasn't as great.
1. Well would 20 fish be enough to make a difference because that’s all that died in the kill?
I was wondering if the fertilizer I tried did it? I stopped using it after the fish kill.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=234871http://forums.pondboss.com/ubbthreads.php?ubb=download&Number=1778&filename=IMG_4627.JPG
Well last night it poured and raised the pond to the point that the over flow kicked in a drained down about a foot of water, so the pond netted about 2.5' of water level gain.
If that amount of rain and the turn over doesn't kill fish then I'm thing that it was the fertilizer that caused the first fish kill. My assumption of the fertilizer has one variable in it the fish kill happen when it rained hard after an extended dry spell lately we have been having hard Rains almost weekly so the pond may not have had time to stratify between rains.
Well last night it poured and raised the pond to the point that the over flow kicked in a drained down about a foot of water, so the pond netted about 2.5' of water level gain.
If that amount of rain and the turn over doesn't kill fish then I'm thing that it was the fertilizer that caused the first fish kill. My assumption of the fertilizer has one variable in it the fish kill happen when it rained hard after an extended dry spell lately we have been having hard Rains almost weekly so the pond may not have had time to stratify between rains.
What I ment was I think the fertilizer combined with the turn over caused the fish kill back in May, does that sound correct?
Does anyone have any other thoughts on it?
I think it was most likely the turn over alone. It takes some time for the colder water layer underneath the upper to stratify, more time to become anoxic, and then even more time for that layer to form other toxic gases (Methane, Hydrogen Sulfide, Ammonia, CO2, etc.).
If your pond is not able to stratify between rain events, these will not form or be degassed to the atmosphere and a fish kill will likely not happen.
This is why effective aeration is so important in ponds.
Your problem sounds a bit like mine. Except I'm further north and losing trout. My losses also started after a huge rainfall. Based on the research I've done, I'm guessing my problem is low oxygen too. Ordered an aeration system today. I figure even if its not an oxygen issue the adduitional aeration can't hurt.
Anyone got a different opinion?