Over the next month, fish are going to move to shallower (warmer) water as lakes start to freeze. Pay attention to where you are catching fish in December as a layer of ice doesn't change their pre-season spot. First Ice should come and you should be able to walk up to that same spots you fished a week ago and get into the same fish that was there when you had to use your boat.
They will stay up in the shallow water for the first couple of weeks before the oxygen runs out, then they will gradually move deeper and deeper following water that is oxygenated, yet still warmish.
A good sign that the area is oxygenated is clear water, green weeds, etc. You will know when the water goes bad as there will be a milky film like substance that makes the water cloudy. This is produced by rotting vegitation. Weed puss if you will. It's pretty nasty stuff. If your not catching fish where you were 2-3 weeks ago, zip up your shanty and look down the whole in that same First Ice Hot Spot will look like cloudy nastiness.
