The slight increase in DO was maybe, maybe not due to extra oxygen production at the bottom. Here are some possibilities.
1. Meter error, variance, or calibration error.
2. Increase of inflow, seepage of ground water that contained some dissolve oxygen and remained near the bottom.
3. If your water clarity is adequate to allow 1% of surface sunlight to reach the bottom and there are either submerged plants (rooted or attached algae) on the bottom they could be making some oxygen and the oxygen is accumulating at the near bottom, sediment water interface so hopefully the removal of snow did help increase DO where the 'plant' density was greatest the bottom area or aka benthic zone.
I went back to the weekly data page and saw that the water clarity at freeze up was around 6ft. This means that without ice cover green plant photosynthesis can occur at 1.7 to 3 times the Secchi disk reading; in this case 10.2 to 18ft deep depending on the water characteristics. If we account for ice cover reducing light penetration the amount of light that penetrates through the ice and into the water is probably not very much compared to ice free conditions. Thus my WAG estimate is day light penetration through 12" of ice would at a maximum be 1 to 1.4 X the Secchi disk reading. We do not have a secchi disk reading for the current conditions of Dwight's pond. Dwight if you or Stick cut an ice hole big enough to drop a Secchi disk, check the measurement.
Bill, that was priceless!!!
