YOUNGSTOWN - Hundreds of fish found dead at Mill Creek Park over the weekend died from lack of oxygen and stratification of the water, a park spokesperson said Monday.
Linda Kostka, development and marketing director for Mill Creek Metroparks, said the results from testing of the water in the park's Lily Pond confirmed what they already suspected.
"They died from a lack of oxygen," she said, adding that Saturday morning storms coupled with high temperatures likely contributed to what's called "summer kill."
The water testing was conducted Monday by Youngstown State University.
According to the Ohio Department of Natural Resource's Division of Wildlife, cloudy and hot summer days or dramatic weather changes can contribute to summer kill. The condition occurs most commonly in shallow ponds that are heavily vegetated and have high accumulations of decomposing organic matter, the division said.
Park officials were first notified of the dead fish on Sunday afternoon. Kostka said the fish were mostly koi and goldfish, and it was unknown how many fish remain in the shallow pond.
"We don't know what's left, but I don't think it was every single fish," she said.
This is the first summer kill the park has experienced in many years. Kostka said she recalled a winter kill more than 10 years ago, but couldn't remember the last time she or other officials had seen a summer kill.
The parking lot near the pond remains closed while officials get the pond back in order. Kostka said it should be open by mid-week.