Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations winter kill

This years global warming has produced excellent conditions for a major fish kill. 28 in. ice and record snowfall. I installed an areation system in Feb. It blew a large hole in the ice near the shore. Ice fishing is now producing only small bluegills. Now the ice is half gone. When can I tell if a winter kill has happened? Thanks ,Kevin

Hey kjmiller,

I was going to respond to your question, that here in Iowa the DNR and citizens are reporting record winter kills but then I saw you were in Iowa so never mind you probably already know.

To answer your question, with my opinion, you will know when the water temps start to warm up and you start feeding your fish. You can then observe who comes to dinner. Also a seine and a line survey might help after waters have warmed up some.

The experts should be along shortly to confirm or deny this opinion.

Feeding and angling when surface water temps get arourd 55F-60F are probably the easiest ways to determine what fish are present after a possible winterkill. If you do not see or catch some fish near the sizes you knew were present last fall them a partial winter kill likely occurred. Hopefully the aeration helped reduce affects of a severe winter. But in a large surface area pond the open water produced by one diffuser is pretty small in comparison to the entire surface of a large snow covered pond small lake.

I am a very firm believer in regularly removing snow from the ice irregardless of ice thicknesses greater than 20". Enough light can penetrate very thick ice to cause oxygen produciton by microscopic plants to prevent winterkill. As a general rule as the ice gets thicker one should then remove an increasingly greater percentage of snow from ice to allow more light to penetrate through ever increasing ice thickness. There is probably a general rule for this, but right now I hesitate to provide a formula for this.