Winterkill Question

[rangerforme]

How fast does Winterkill happen in a lake? I've been fishing a small 100 acre lake in the metro and everytime i've been catching 30-60 fish mostly in the 7-9 inch range for gills and 10-12 inch range for crappie, nice big fish. I went out this weekend and drilled the entire lake and never marked a fish. The whole lake is 10 feet deep or less but just last weekend I hammered them. There were a few others on the lake that this weekend and no one else iced a fish either. I'm afraid it winter killed but I'm just suprise it could happen in a matter of days??

PS - I've only kept about 10 fish this year out of there so i know there should be some left in there!!

[Scott M]

It's entirely possible that many fish have kicked the bucket. How quickly winterkill happens depends on how many macrophytes (aquatic vegetation) are producing oxygen in the lake and the size and condition of fish, the depth and size of the lake, and how much snow cover is on the lake. Size, sex, and habitat preference can dictate how much oxygen an individual fish needs. Some years winterkill may affect only a portion of a lake (Whaletail in Hennepin county is a great example) or a portion of the population (certain size classes or fish inhabiting a specific part of the lake).

As far as your small 100 acre lake that you aren't marking fish in, if you put the time in and didn't mark the fish in a lake that small, it may be safe to assume there is some winterkill. The best way to tell is to get a dissolved oxygen reading. Right about now is the time of year when a dissolved oxygen curve of the lake is at its lowest point. More respiration is happening in the absence of photosynthesis, so dissolved oxygen really drops until that snow melts in mid to late March and plant production finally picks up.

[fisherman-andy]

I don't think their dead. Fishing patterns can change and all of sudden what worked may not. Plus I don't think locators/Sonars do all that well in shallow water. It's also possible that the fish may scramble from the signal also.

Drop a underwater viewing camera in the areas you were having success before to see if you can at least see them.