Hundreds of fish die in Lily Pond

Dissolved oxygen is believed to be the cause of the fish deaths

Dead fish float on Lily Pond


Dead fish littered the shoreline and floated on the surface of Mill Creek MetroParks Lily Pond, caused by a lack of oxygen.

Park maintenance workers used nets Monday morning to scoop the dead carp, koi, catfish, bass and bluegill out of the pond, carrying them away in buckets.

Linda Kostka, park development and marketing director, said the Mahoning County Soil and Water Conservation District has taken samples of the pond water and park officials have consulted the Ohio Environmental Protection Agency and the Ohio Department of Natural Resources.

“The sample taken by [Youngstown State University] shows what we suspected: lack of oxygen from the storm Saturday, the high heat and the lack of rain,” she said.

Steve Avery, park planning director and landscape architect, said dissolved oxygen is caused by a combination of high temperatures and a shallow pond. Avery said the pond is about five feet deep.

The fish suffocate from the lack of oxygen.

The pond is closed until further notice.

According to the website of the Texas A&M Agrilife Extension, dissolved oxygen is the most common cause of fish kills in ponds and most occur in the summer. The oxygen demand in a pond is higher in the warmer months and colder water holds more oxygen than warmer water, the site says.

ODNR Division of Wildlife’s website says that summer fish kills are “most common in shallow ponds that are heavily vegetated and have high accumulations of decomposing organic matter.”

The problem didn’t kill all of the fish, however.

“You can still some fish swimming around in there,” Avery said.