Help, I have a three year old pond in southwest Ohio that has recently experienced a fish kill. Went up last night and counted ~100 6" to 8" bluegills and about 3 to 5 bass. Pond is subject to about 10 acres of runoff from a planted field, and has a serious slick/bloom on top of the pond. I have had an aerator going constantly for last three months, and have only recently noticed a fish kill. I am able to see about 12 to 14" down in water. All dead fish are about the same level of decomposition. Last week we had about 3 to 4 days of cloudy weather that probably caused too much oxygen drop. Pond was originally stocked with 300 bgill, 100 hybrids, and 200 bass in the 3" to 5" range plus several additions of fathead and shiner minnows. My questions are:
should I do anything now in case of more cloudy weather causing a repeat?
Is there anything that can be done about all the runoff, (I've called county soil and water)?
Do you think I've also lost more bass, but just don't see them?
I appreciate any and all help, thanks for such great forum!
Bill

Fishy,

Could your aerator be adding to the problem of your fish kill? You stated your pond is three years old but you've been aerating for the past three months. I'm not an expert but there have been cautions posted in the past about initially setting aerators too deep in older ponds. Doing this can result in all the nasty buildup from the lower depths being brought to the surface. I think one post mentioned that if you experience a sulfur smell thats bad news. Do a search and see what you find out. Hopefully one of the biologists can expend on this.

6" to 8" bluegill, thats a tough loss to take.
Good luck.

Russ

fishy,
Sounds like low DO. On cloudy days & at night a thick soup of bloom will use more oxygen than it produces causing a die off of the bloom which in turn drops DO even more from decompsition of the dead plankton.
Right off I would only run the areator at night & on cloudy days. Operating during the day encourages the algea growth.
Give a little more info & maybe someone with some expertise will respond. IE: pond size, avg depth, have you fertilized, what type of areator, ect.
Also do a search on this site for "algea", & "bloom", & "fish kill"
Ric

Pond is ~1 acre, avereage depth is about 8 to 10 ft, I have not fertilized, but I think I have received fertilizer from the crop field that runoff goes through. My thought was also low DO, is there more I should do to help? I have a DA-1 aerator. I did start the aerator on a schedule to prevent too rapid mixing of bottom water at start-up.

Thanks to all, still open to all ideas.
Bill

fishy,
Sounds like you were doing it right. BTW I never assume otherwise.
I was suggesting not operating the areator during the day only now that you have too much bloom as operating when the algea is producing oxygen will help you keep too much bloom.
There is ALOT of info already on this site & it's easy to search for. Choose [search] in the upper right corner of this window. Under SEARCH WORDS type [fish kill] Under SEARCH FORUM try [Questions and Observations] Under SEARCH IN choose [Subject Only]
Ric

Russ, thanks for your help and ideas
Ric, thanks for your ideas, I don't live there, but will be up there this weekend and will put a timer on the aerator to only run during the night.
Do you think I will be subject to another kill, if we get more cloudy weather? Should I consider buying a fountain to run at this time of the year? I know it's a lot of money, but I'm 56, and looking to fulfill one of my lifetime plans, and would go that route if necessary.

Again, thanks to all.