By Denise Dick
Dead fish littered the shoreline and floated on the surface of Mill Creek MetroParks Lily Pond, their deaths 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 5 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 see some fish swimming around in there,” Avery said.
Two park employees used a row boat to reach and remove the dead fish in the center of the pond. Others stood on the shore, gathering the carcasses that collected near the water’s edge. Masks covered their mouths and noses to cut down on the stench.
Gouges from the bodies of many fish along the shore indicate that something, likely turtles, made meals from the bodies.
The dead fish are being buried at the park’s maintenance facility, Kostka said.
Kostka said that a couple of weeks ago, the big storm that moved through the area caused a temperature inversion in the pond, killing some fish.
But the number that died was much lower than the latest problem that occurred over the weekend.
“We started getting calls about it Sunday afternoon,” she said.
The park plans to restore the pond — the oldest man-made body of water in the park district — and has been raising money. Estimated cost is $380,000.
The trail circling the pond will be restored and a handicapped-accessible observation platform added to allow visitors to sit or walk and get a better look at the ducks, geese, fish and other wildlife in the pond.
At the end of the pond farthest from the main parking lot, a boardwalk will replace a portion of the trail, stretching over the water.