I’m hearing the lakes on the cisco chain are in the process of the fall turnover. But as of Thursday, the 22nd, the water temperature topped out at 56 degrees and as you will see below, turnover will be coming soon.

The truth is, fall turnover depends on the size and depth of lakes. Small lakes that do not have a thermocline do not turnover and the only way to really know the start of turnover is with a thermometer. Some older timers always told me, you will know turnover is happening because of the smell of the lake. (MORE ON THAT LATER).

SO, for those that do not know what or how fall turnover happens here it is. The top water sinks and the bottom water rise, that’s pretty much it. But here is a better explanation.

Basically, lakes have three layers,
1) EPILIMNION, is the upper layer that is warmer, with moderate to high levels of oxygen.
2) HYPOLIMNION, is the deep water that is the coolest and has no or little oxygen.
3) THERMOCLINE, Anglers know this is the transition layer between the warmer water above and the cooler water below.

When the lakes surface temperature reaches and holds around 50 degrees, the top highly oxygenated water layer becomes denser and will start to sink. This causes the colder poorly oxygenated less dense water to rise to the top. At this point the entire lake temperature becomes similar with oxygen distributed throughout the lake and turnover will be complete at 39 degrees.

And this is why some say you can smell turnover. The poorly oxygenated bottom of the lake has decaying matter causing sulfurous gases and when this colder water is pushed to the surface the lake can have a slight rotten egg smell. This action actually helps clean the bottom and adds oxygen for the new deep weeds to grow come early summer.

Well, that is the basics of fall turnover.  Fishing can be tuff during turnover, and some will not go out on the water at this time of the year. But I will write about that next week.

Some may not know this, but there is a turnover in the spring also and I’ll cover SPRING TURNOVER and how it will affect your fishing at that time.