Winter fish kills and oxygen depletion on ponds are particularly common in Iowa, especially on ponds with high nutrient loads, heavy aquatic vegetation prior to freezing over, and those with small surface area and shallow water depths. See the Iowa State University Extension & Outreach news release for November 20, 2013 for more information on preventing winter fish kill in your pond.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on November 22, 2013. The information contained within may not be the most current and accurate depending on when it is accessed.