Nate - not surprised at all how much fish move under the ice as I have seen them. That was not the point. The point is that BG (and other fish)try to minimize energy use while maximizing energy input subject to static energy demand for involuntary body functions. So when considering the many factors effecting where to fish for warmwater fish like BG under the ice (or in cold water)include the location that best lets them maximize their energy use at the time when their food is most available.

Cecil yes - but YP are not a warmwater fish, are quite active under the ice/cold water and feed on small BG quite easily as the YP metabolism is on go while the BG metabolism is slowed. The YP-BG relationship is similar to LMB eating tilapia in southern waters when the water temp is in the low 60's. There you have a warmwater fish (LMB) easily eating a tropical fish (tilapia) as the tilapia becomes slowed just above its lethal thermal minimum temp.

If we could ever understand all the biological factors which effect fish and know how to rank and integrate them for behavior then fishing would be easy.

Bill I agree ice must cause an effect on pressure as you have water under a pressure/weight exceeding that of the atmosphere within essentially a closed vessel at least until the pressure build up along with other forces cracks the ice. I wonder how much difference there is in pressure between an iced over pond and its twin that has open water due to aeration.