The Louisiana Department of Wildlife and Fisheries (LDWF) says it needs your help with spotting fish kills that may occur throughout south central and southeast Louisiana in the aftermath of Hurricane Francine.
Hurricane-related fish kills are generally caused by low dissolved oxygen (DO), and can occur from landfall of the storm until weeks after the event. The main factors contributing to hurricane-related fish kills include storm surge, the churning up of oxygen-poor water and sediment due to wind and rain, and the sudden input of large amounts of organic debris into waterways.
Following the event, organic matter will begin to decompose, and microbes will deplete the DO from the water causing fish to “suffocate.” These factors can work alone or in conjunction to cause fish kills following a hurricane.
Storm-related fish kills have occurred in Louisiana since before recorded history, and the ecosystems have evolved to be resilient and bounce back from them. Decomposers and scavengers including microbes, crawfish, crabs, fish, alligators, turtles, raccoons, and birds will do their part helping to clean up fish carcasses.
Many fish and aquatic organisms will find refuge from the low DO waters, and participate in the boom year of reproduction that normally follow such events since there will be fewer predators and more resources available by next spring.
While fish kills are shocking to experience and can appear devastating, they can lead to a rejuvenated system that is healthy and naturally replenished in the following years if the system has time to recover.
Some of the same areas still recovering from Hurricane Ida will be impacted by this storm. Natural sportfish recovery from Hurricane Ida was going well, and as expected, with bass and crappie beginning to reach desirable sizes for anglers. Unfortunately, this storm could restart that process for some areas, as well as impact areas further to the west.
LDWF biologists have learned through our sampling and monitoring efforts that restocking following storms is not usually necessary and will not speed up the recovery process unless there is a complete kill in a closed system. However, we need to know where fish kills occur and how extensive they are so that we can monitor recovery and consider management tools going forward, including habitat restoration or stocking, if needed. Please help us by reporting fish kills in your area.
Call 1-800-442-2511 or your local fisheries office to report a fish kill.
For more information about the causes of fish kills, visit our fish kill webpage.