The Louisiana Department of Wildlife and Fisheries (LDWF) reminds the public that increased water temperatures, storms, and extended cloudy weather can lead to fish kills in inland and nearshore waters across the state. These events are typically caused by low dissolved oxygen (hypoxia), which often occurs in warm water, since it has a lower carrying capacity for oxygen than cooler water.  Conditions such as stagnant water, heavy rainfall, decaying vegetation, or increased nutrient runoff contribute to hypoxic conditions—especially in shallow bayous, marshes, and ponds.

Fish kills may affect certain species or sizes more than others. For example, shad are sensitive to hypoxia, and are often the first or only fish that experience a fish kill, while some species, like gar, can breathe air and are resistant to hypoxic conditions. Other species have varying levels of tolerance to hypoxic conditions. 

While fish kills can temporarily impact recreational and commercial fishing, aquatic ecosystems in Louisiana are resilient and typically recover naturally. Even in large fish kills, some fish will find refuge from hypoxic conditions in the affected waterbody or connected waterbodies and survive. Scavengers and decomposers help break down fish remains, and most systems recover over time. If conditions remain favorable, fish populations often rebound after major kills within one to two years without the need for stocking, and young fish benefit from reduced competition and increased resources. However, fish kills caused by pollution or chemical spills can occur at any time and may require additional response.

Documenting fish kills in Louisiana, whether caused by natural or human-caused events, is important to responsibly manage fisheries resources. Please report any observed fish kill to LDWF so biologists can investigate and document the kill as soon as possible. For information on how to report a fish kill or more information about the causes of fish kills, go online to wlf.louisiana.gov/page/fish-kills.