Pond Boss Forums INTRO Questions & Observations trying to prevent winter fish kill

RAH, the larger the fish, the more suceptable they seem to winterkill. I doubt that you have lost all of one species, but probably the larger of each species.

Do you run an aerator during the winter?

I still have 6" of ice on my pond, the top 5" is milky white. We just got 5" of snow Thursday night and another 1" last night. I was fortunate that Cecil let me borrow his O2 meter this winter. I kept tabs on the O2 for a study that Dave Willis is doing on groundwater ponds. I monitored my pond and 4 others that are also groundwater ponds. Some aerated, some not. I didn't run the aerator in my pond this year for the study, and had a low O2 reading in the high 5mg/l range near the bottom in 11' of water. The lowest high reading was in the 8 mg/l range up right below the ice. My pond is less than an acre now due to the drought we've had here in late 2010. With the snow cover and thick ice, it is apparent that sunlight getting thru the ice helps O2 levels under the ice more than you think. If shoveling off the snow or running an aerator is not an option, then I would look into running a pump (even off of a generator for a day) to pump water on top of the ice to melt the snow, allowing more sunlight thru the ice.