Harsh winter brings fish kills to Valley ponds

By Robert Connelly



Kim Dietz went into her backyard on the first day of spring to take pictures of the ducks that fly back every year for the seasonal change.

She saw something by her 20-by-25-feet pond, and as she got closer, she noticed one of her bigger carp dead on the ground.

She found more clusters of dead fish, took photos with her phone and made a posting to Facebook. Two people replied to her post that they had similar cases, but had ponds shallower than Dietz’s 20-foot-deep pond.

This is called a winter fish kill, or winterkill for short. The Ohio Department of Natural Resources defines a winterkill as “when persistent ice forms a surface barrier between the water and air that prevents circulation of oxygen and blocks sunlight.” The lack of sunlight causes plants to stop producing oxygen, and the plants begin to die off and decompose.

The Mahoning County Soil and Water Conservation District said winterkills have been common this year. Kathi Vrable-Bryan, district administrator, said it has had several calls about winterkills from rural residents with ponds.

Vrable-Bryan said winterkills don’t “happen very often in Ohio ... we don’t think how [cold weather] affects wildlife and nature.” She added that the district recommends shoveling snow 2 inches or deeper off of a frozen pond. Another tip, if an aeration system is installed, is moving it closer to the surface to prevent it from freezing.

Dietz said her pond is 30 to 35 years old and they’ve never experienced a winterkill. Dietz said a representative from the conservation district didn’t come out and she was disappointed, but she was visited by an independent tester, John Williams. Williams, trained by the Alliance for Aquatic Resource Monitoring, tested her water for pollution. All the levels came back normal, indicating a lack of oxygen — meaning the fish died from a winterkill.

Williams originally came to Dietz’s property because a horizontal shale well runs through her property. In an email, he told Dietz he came out to test her water because of concern with that well, but did not find any pollution in the pond.

Dietz is waiting for access to her pond to be easier with warmer weather before she removes the fish and puts them in her garden or buries them. She plans to buy 50 to 75 fish later in the year “because you have to account for the ones that aren’t going to make it.” She said her children and other family members feed the fish when they come over or even fish in the pond, releasing the fish after every catch.