Lake Turnover

Category: Conditions

Lake turnover is a seasonal event, typically occurring in fall, when cooling surface temperatures equalize with deeper water temperatures, breaking down the thermocline and causing the entire water column to mix. During summer stratification, the bottom layer (hypolimnion) accumulates decomposing organic material that depletes oxygen and produces hydrogen sulfide and other compounds. When turnover remixes this stagnant bottom water with the upper layers, the entire lake temporarily becomes murky, low in oxygen, and smells of decay. Fishing during turnover is notoriously difficult — fish become lethargic, scattered, and reluctant to feed as they adjust to the changed water chemistry. Turnover typically lasts 1-3 weeks depending on lake size, weather conditions, and depth. Fish behavior during turnover is unpredictable: they may move shallow, suspend at random depths, or concentrate near inflowing streams where fresh, oxygenated water enters the lake. The best strategy during turnover is to focus on areas with current or fresh water input — creek channels, river inflows, wind-blown banks — where water quality recovers fastest. After turnover completes and the water column stabilizes, fall fishing typically improves dramatically as fish begin aggressive pre-winter feeding.