The Iowa Department of Natural Resources is investigating two separate fish kills in central Iowa’s Hamilton County — one on the South Skunk River, the other on a tributary.

Water samples in the tributary were tested for levels of dissolved oxygen, acidity and ammonia. All test results showed normal levels, indicating the fish kill did not result from excessive fertilizer or manure in the stream.

Landowners in the area have reported aerial spraying, possibly of a corn fungicide, in fields next to the tributary stream.

The small area affected by the fish kill-about one mile of stream-is typical of chemical drift from aerial spraying.

Specialists will continue the investigation to identify the responsible party. The Iowa DNR will test water samples to confirm chemical contamination. Test results should be available within the next two weeks.

The DNR fisheries section is on site to inventory the number and types of fish killed.

Pat Powers, KQWC, Webster City