CHARLES CITY — The Iowa Department of Natural Resources says they are continuing to investigate a fish kill earlier this week in Floyd County.

The DNR says specialists looked into a fish kill on a tributary of Flood Creek about four miles west of Charles City on Wednesday. On-site field tests did not show elevated ammonia levels and live fish were seen along the affected two-mile stretch of stream, indicating a pollutant had moved downstream.

The DNR says although dead fish were reported to another agency on Tuesday afternoon, the DNR did not learn about it until Wednesday.

DNR environmental specialist Rachel Glaza says it’s important for people to call the DNR right away when they see dead fish so they can try to determine a cause, but in this case, whatever caused the fish kill had come and gone by the time they started investigating.