State fisheries biologists say they are anticipating fish kill reports in Southwest Mississippi related to the historic tropical-like system that had flooded many areas of the coastal areas of Louisiana and Mississippi.

The heavy rains can cause a phenomenon called “lake turn over” that can deprive fish of dissolved oxygen.

“The combination of heavy rains, organic debris washing into ponds, and extended cloudy weather may result in oxygen depletions,” according to Jerry Brown, the region’s fisheries biologist for the MDWFP. “Low dissolved oxygen levels in ponds are common during August and September when heavy rains rapidly cool warm surface water allowing it to mix with cold, low oxygen bottom water. 

“Also, a heavy influx of debris, such as leaves and pine straw, washing into ponds can result in low oxygen as the organic material is broken down. Periods of extended cloudy weather can cause phytoplankton blooms to crash suddenly due to the lack of sunlight.”

Fish kills that occur on public waters should be reported to the Mississippi Department of Environmental Quality at (601) 961-5171.  Private lake and pond owners can report fish kills to the MDWFP Fisheries Bureau at (601) 432-2200 (Monday-Friday, 8 a.m. to 5 p.m.).