The state Department of Natural Resources says it's investigating a fish kill in northwest Iowa.
Officials say a conservation officer reported seeing dead fish and crawdads in an unnamed stream Tuesday in Lyon County. Further investigation Wednesday revealed dead fish of different sizes and species in the stream. It is unclear how many fish have been affected.
The stream flows into Rat Creek, a tributary of Otter Creek between Ashton and George.
Officials say aerial spraying is the most probable cause of the spill, but lab results are still pending. Three aerial applicators were flying in the area Tuesday.
This is the second recent fish kill in Lyon County. Officials believe it was caused by aerial spraying.