DAVID CITY — Visitors to the David City Park would be wise to avoid contact with the lake water while local and state officials try to determine what killed several hundred fish starting last week.
Park Supervisor Scott Bales said he called in officials from the Nebraska Game and Parks Commission and Nebraska Department of Environmental Quality after finding fish at the east end of the middle lake.
Bales said most of the fish were bluegill, the most populous fish in the lakes, but "some of them are bass that I never catch."
On Wednesday, Bales found a 34-inch grass carp that weighed 40 pounds.
DEQ Program Specialist David Bubb said people should avoid contact with the lakes and keep their children or dogs from touching the water for the next few days.
Bubb said the lakes were tested and appear to have plenty of oxygen. The cause of the fish kill is not yet known.
One possibility is ammonia, but Bubb said he couldn't pinpoint the source.
"It almost looks like something dropped off a bridge," Bubb said. "It's kind of perplexing right now."
Bubb also didn't advise eating any fish caught in the lake over the next few days, but he did say the problem causing fish to die would clear up.
As of Monday, he said, fish in the western lake were being affected. Bales said he first noticed dead fish April 24 and they are being removed from the water.
Bubb said the stream feeding the lakes was examined and showed a healthy population of frogs, which indicates the problem is not up stream from the lakes.
The lakes are part of the state's Urban Fisheries Program and stocked periodically with trout.
Bubb said rising temperatures in recent days were starting to cause some stress for the trout in the lake.