Cold fronts that affect fish historically occur in January and February in the state of Florida, and we seem to be getting our fair share of them.
Florida is experiencing a third extended cold snap with temperatures from the upper 20s through the 40s from north Florida to the Keys. There aren’t many Floridians who like the change in weather and temperature. The fish in your lake don’t like it either. An unusually strong and prolonged cold front can have a devastating effect on Florida’s freshwater fisheries as we saw during the record setting 2010 cold spell when millions of freshwater and marine fish died around the state. As water temperatures drop many species of fish will become stressed and if temperatures continue falling a significant fish kill may occur.
Our non-native tropical fish species are stressed when water temperatures drop below about 55°F, so we can expect to see occasional fish kills throughout the state during most winters. Tilapia, Peacock bass and cichlid species are particularly vulnerable to cold temperatures and especially when temperatures drop more than 2°F per day. You may see dead fish even after the temperatures warm back up because it sometimes takes several days for the fish to die and float to the surface.
Unfortunately, Florida’s native sportfish, like the Florida largemouth bass, are also sensitive to severe cold weather after becoming acclimated to Florida’s normally warmer water temperatures. Marine species like redfish, snook and others that are found in shallow areas of Everglades National Park and other state estuaries are also vulnerable to harsh weather conditions. The good news is that it is very rare that a fish kill wipes out an entire fish population of a lake or every fish of a particular species. Most often, the survivors reproduce quickly to eventually return balance to the lake’s ecology and fisheries.