If you begin to notice that your pond has multiple deceased fish floating to the surface this time of year, you could be experiencing pond turnover. This occurrence isn’t from chemical runoff or disease pathogens.
As we have all experienced, Burke County has encountered multiple rainstorms throughout May and the beginning of June. With these storms have come strong winds, heavy rain, rapid changes in temperature, and many subsequent events later in time, like pond turnover. The rain that we have experienced causes the structured layers in a pond to mix.
You may ask, what are these layers? Layer one is the upper layer where much of the pond’s algae and other oxygen providing factors are located. Layer two is the mixing layer, which is a small zone where the layers meet. Here, the temperature changes and serves as a barrier to the third Layer- the bottom layer. This area of the pond is very stagnant and cool with small amounts of oxygen.
So, when the rain destratifies the pond layers, which disperses oxygen throughout the entire body of water, it’s now creating a lower concentration of oxygen available for fish. Signs to look for would include fish gulping for air at the surface and death. The only way to prevent this from occurring would be to implement a strategy to aerate the pond, especially at night when oxygen levels are generally at its lowest. Additionally, try not to overcrowd or feed your fish as this can be stressful and impactful on the pond.
If you have the ability to begin aerating your ponds, now would be a good time to do so. Please feel free to call our county extension office for any of your Ag and Natural Resource needs at 706-554-2119!
Source:
Colquitt County Ag Report. (2013). Oxygen depletion and pond “turnover.” UGA Cooperative Extension.
Shelton, Dr. J., & Gerrin, W. (2023). Diagnosing Fish Kills: Important Questions for Landowners. University of Georgia D.B. Warnell School of Forestry and Natural Resources. https://bugwoodcloud.org/resource/files/27816.pdf
Shelton, Dr. J., & Gerrin, W. (n.d.). Understanding fall pond turnover and Fish Kills. Warnell School of Forestry and Natural Resources. (2025)
Shawn Murphy – Burke County Extension ANR Intern
Cliff Collins- Burke County Extension ANR Agent