What is Winter Fish Kill? “Winter fish kill” occurs when a pond is completely covered with ice and a layer of snow. The fish hunkered down at the bottom of the pond are using up the oxygen in the water, and this “winter fish kill” can happen when their supply is not replenished in time.

Do all fish die in the winter?

The longer a winter lasts and the shallower a body of water is, the more likely it is that the fish in it will start to die off from a lack of oxygen. Different types of fish have different abilities to tolerate these low-oxygen conditions.

Does snow kill fish?

If snow and ice reduce the amount of sunlight available to the plants, the level of dissolved oxygen in the water falls, resulting in fish kills. Although winterkills are not uncommon, this year's heavy snow, later in the year, has resulted in an unusually high number of fish kills.