Fish Cages Froze in Ice. I routinely allow my floating fish cages to freeze in ice cover. My cages are 32" to 40" deep from the water surface. My fish appear to be in good shape when the ice thaws in spring. Occassionaly I have drilled holes in the ice and dropped sinking food in the cage and watched fish eat sinking food. When I looked at my old water temperature measurements during ice cover the water at 3 ft deep ranged from 39F to 39.2F.
I will do more temperature measurements this winter to get a more detailed profile of the water temperatures just below the ice down to 5 ft deep. I will also measure the bottom water heating affect at various depths.
